Rotary News has posted an official announcement from Mazda Engineering regarding dyno testing the RX-8. It explains the power reduction modes that happen when running an 8 on the dyno.


From the Rotary News article (http://rotarynews.com/view.php?id=212) :
Statement:

There is no true way to generate flywheel horsepower from a chassis dynamometer because of frictional losses in the driveline, clutch, transmission, differential and tires. Also, variations in testing procedures will cause highly disparate readings: open/closed hood, high/low humidity, high/low ambient temperature, tire pressure, how tightly the car is tied down, which gear the car is tested in, etc.

In addition, we have determined that, in order to prevent damage to the catalytic converter and the entire driveline, when the PCM determines unusual operating parameters such as excessive slip in the drivetrain from the front to the rear wheels, it causes a rich high-RPM mixture and retardation of the timing. All these items combine to cause apparent considerable horsepower loss.

BACKGROUND:

Horsepower Measurement

There is only one true method for measuring engine horsepower: on an engine dynamometer at constant speed and utilizing variable load.

The engine should use the same intake and exhaust system as in the car. HP results must be corrected to SAE J1349 standards as listed below:

77 degrees Fahrenheit
Sea level
0% humidity
Correction factors must be applied to reference the measurements to SAE J1349 standards. Any correction factor beyond 7% is considered invalid.

Chassis Dynamometers

SAE has produced a technical paper (SAE Technical Paper Series 2002-01-0887) that attempts to address the ongoing debate about inertia dyno horsepower versus OEM net horsepower. You can order a copy by visiting their website at www.sae.org -- we have no intentions of getting mired in the middle of this discussion.

Bottom line: If used properly, chassis dynos are great tools to assist with tuning and modifying vehicles. It is impossible to measure the actual flywheel horsepower because there are simply too many variables.

Other issues that are unique to the RX-8:

The RX-8 uses a very advanced engine management system. Besides precisely controlling the operating parameters of the engine, self-preservation (of both the engine and the catalytic converter) is also considered.

The engine management system continuously monitors all engine functions and adjusts accordingly. For example:

Under heavy load acceleration, the timing is retarded and the fuel mixture richened to reduce the likelihood of pre-ignition or spark knock. If spark knock is encountered, a knock sensor senses the condition and further retards the timing. Gradually timing is advanced and fuel mixture leaned after the load is reduced.

A second reason for fuel enrichment is that when timing is retarded, exhaust temperatures increase; a richer mixture lowers the exhaust temperatures and reduces the chances of damaging the catalytic converter.

In real world driving, this all goes unnoticed to the driver and appears seamless with no disruptions to the performance of the engine. The car encounters a load under acceleration but the load quickly diminishes as the car accelerates in each gear.

Operating on a chassis dynamometer, however, creates a completely different environment. Inertia dynos use a known mass that is accelerated to measure torque at the wheels. This is usually done in one gear under heavy load conditions:

Only the rear wheels are turning while the front tires remain stationary.

On cars equipped with DSC with traction control, the difference in speed between the front and rear wheels is sensed and the power is reduced immediately to compensate for what the car senses as excess wheel spin.

If the DSC is turned off, the traction control is disabled but the brake functions of the DSC are still operational.

If the DSC system is completely disabled, this removes the brake functions from the equation, however it does not fully remove the engine management system functions.

The ABS hydraulic unit/control module (HU/CM), or the DSC HU/CM for cars with DSC, determines vehicle speed by comparing the speed of all four wheels. If two are turning and two are stationary, it will still compute a speed but senses that the car is experiencing excessive wheel spin. To protect against engine or catalyst damage:

The engine management system compares the throttle opening, gear selection (determined by engine speed and road speed) charging efficiency and engine coolant temperature to determine the driving condition.

Since the car is under heavy load, in a tall gear (testing is usually performed in third or fourth gear), with a wide throttle position angle (wide open), spark timing is reduced and the fuel mixture is richened to reduce the occurrence of spark knock and to reduce catalytic converter temperatures.

There you have it, folks - right now, all dyno tests to date on the RX-8 are not showing the true power output of the Renesis.

I hope all the scare mongers who have spend the past 2 months bad-mouthing Mazda and the RX-8 (you know the ones - "Mazda lied to us and cheated us") will now be man enough to admit they were wrong and post apologies!! (Yeah, like that would ever happen) :D

Regards,
Gordon

Well to me the car must have at least 238hp, after test driving the 350z with it's 287hp I expected to be wowed by it's power. It was underwelming and not really much faster.

Is there such a thing as a dyno that has the all wheels spinning via pully from the driven wheels?

maybe if so that could put this Mazda statement to the test and settle the debate and quiet the naysayers once and for all. Just one dyno graph of a 4 wheel dyno would solve the puzzle!

Then we could all just go out and drive our cars rather than debating our cars half the time. ;)

I really don't want to start anything more than I have already have but the article is from RotoryNews not Mazda right?


Vince

Apologies?? for what??

1. They did downgrade stated HP for A reason.

Admitedly the car is no slouch, but c'mon. I was pissed with the HP thing in the very beginning...not much in comparisson to some others. However, I still won't forget a missrepresentation like this one.

Do you think they would have downgraded HP if there was no reason for it? get a load of negative attention + 'Fxxx UP their Sports Sedan (or Sports Car....doesn't matter too much to me) product competitivity in the market? IMHO: NO, they wouldn't even have paid attention if the car was doing things right.

Is the car performing poorly: ITS PERFECT FOR ME. I don't drag race, I don't street race, I need a fun car to take my wife & me from home down the office, and back.

Do I regret it? Absolutely NO; we'll talk again in 100K miles and some oil & filter changes, and maintenance on the record.

Do some people should regret it? Maybe: depending on what they were expecting; but c'mon, if you test drove the car, you knew what you were getting. I did, and I loved it the moment I laid hands on it.

Mazda should regret it? They better do; they better sell shxx loads of it, get more funding from Ford and develop the 7 (or any 2 seater alternative for that reason Rotary powered.)

Why?? Because I don't know if I could be able to drive a piston engine again (as I said before, we'll talk again in 100K miles.)

Cheers!

"we have determined that" gee sounds like to me they should have known this was a issue from the beginning.

Originally posted by compaddict
I really don't want to start anything more than I have already have but the article is from RotoryNews not Mazda right?


Vince

Read RotaryNews... " Mazda has backed [our] hypothesis up with a release of information."

IE, from Mazda...

If you don't beleive so then see the attached screen shot from my inbox.

So, our standing is backed up by actual automotive engineers from Japan. Thereby proving that we know what we are talking about.

Originally posted by compaddict
I really don't want to start anything more than I have already have but the article is from RotoryNews not Mazda right?


Vince

I believe that Rotary News -- as a media source -- was reporting a story from Mazda Engineering (as evidenced by the title of the article). This is significantly different than Dan or Bern posting a personal opinion on this board.

Walks like a duck......


I believe them!

Originally posted by Gord96BRG
From the Rotary News article (http://rotarynews.com/view.php?id=212) :

Under heavy load acceleration, the timing is retarded and the fuel mixture richened to reduce the likelihood of pre-ignition or spark knock. If spark knock is encountered, a knock sensor senses the condition and further retards the timing. Gradually timing is advanced and fuel mixture leaned after the load is reduced.

In real world driving, this all goes unnoticed to the driver and appears seamless with no disruptions to the performance of the engine. The car encounters a load under acceleration but the load quickly diminishes as the car accelerates in each gear.

I don't understand their use of the word "load" here. Surely, the load on the engine is the resistance it encounters as it attempts to turn the driveshaft. This would be a function of the weight of the car and the gearing (and at high speed the aerodynamic drag). So in the real world (as the weight is constant) high load simply means being in a high gear.

Are they saying that it will only produce maximum power in low gears?

And what about "the load quickly diminishes as the car accelerates in each gear". I don't understand that statement at all.

I would like to see a TSB or a statement from Mazda on Mazda letterhead that's all.

It's really not all that much to ask is it?


Vince

he is giving all the info he knows
relax

Originally posted by poison123
"we have determined that" gee sounds like to me they should have known this was a issue from the beginning.




How would you expect them to know something like this? Name one manufacturer that has ever released a vehicle and only advertised rwhp from a dyno. Also this is the first rotary powered vehicle to have these additional safety features.

T-Von the guys who created the system should have known this would fudge results from it. After all aren't they marketing this car as a sports car? I mean they designed the system to retard the car if something abnormal was happening with the wheels, How smart do you have to be to figure out "Hmm all these guys dyno's suck, maybe its because of the safety systems we installed to retard performance if the wheels aren't going like they should" Just a thought

Seems to me that Mazda has started to answer some of the questions being raised.

Engineers are typically myopic and focused on whatever details they have in front of them so it doesn't surprise me that the response took a while.

I do find the endless questioning unbelievable and unjustified. I also credit the engineers who spent the last 4 years developing the car and engine with a better understanding of the dynamics involved than most of the commentarians on this and other threads.

:) Thanks

We should all thank Gord for clearing this issue up. I would hope that no one would expect 238 at the wheels; that's just not possible if the engine makes 238 at the flywheel. As the article states, it is impossible to get flywheel hp without actually putting the renesis on a real engine dyno. I'd like to hear from someone who's actually done that.

As for a real power loss. I'd be more upset about the A/C compressor losses when the A/C turns on when you don't request it. When I get my 8 the first thing I'll do is to run the wire for the compressor clutch in series with the A/C switch so the switch actually controls whether the compressor is on or not.

Now lets stop complaining about phantom power losses and talk about real issues.

Originally posted by GoBerserk
As for a real power loss. I'd be more upset about the A/C compressor losses when the A/C turns on when you don't request it. When I get my 8 the first thing I'll do is to run the wire for the compressor clutch in series with the A/C switch so the switch actually controls whether the compressor is on or not.


I'd make sure to include the temp switch. If you don't and have the dash switch be the only thing that determines if the compressor is on or off, your system will be frozen in no time.

Originally posted by Peter Sawko
Seems to me that Mazda has started to answer some of the questions being raised.

Engineers are typically myopic and focused on whatever details they have in front of them so it doesn't surprise me that the response took a while.

I do find the endless questioning unbelievable and unjustified. I also credit the engineers who spent the last 4 years developing the car and engine with a better understanding of the dynamics involved than most of the commentarians on this and other threads.

:) Thanks


No, i think most of the people on this forum know more about the RX8 ecu than the people who designed and built it, don't you? ;)

we certainly care to find out more than them

Note that:

(1) Mazda USA apparently arrived at their revised 238 HP figure after chassis dyno testing of 11 production cars. The results were then passed through a roomful of lawyers. In light of their latest statement, just how accurate could the revised figure be?

(2) If you read the statement carefully, the circumstances which can generate "considerable horsepower loss" are by no means limited to chassis-dyno-like conditions. Indeed, fuel enrichment and timing retardation appear to occur under any "heavy load acceleration". The latter term isn't defined, but nothing in the statement specifically precludes the power loss from arising in normal operation of the vehicle.

So, the engine makes less power under a load or if the front wheels aren't spinning. The first part puzzles me- is the engine ever not under a load when at WOT? Could the engine ever even reach a torque/horsepower peak if not at WOT? The engine makes less power in higher gears due to increased load?

Odd then that the highest dynos were in 5th gear (a tall gear, even if 1:1) and with regular fuel (high octane would prevent pings or knocks). I guess Mazda thinks it'd be better to dyno in 1st gear with premium?

Interesting that the Jeremy Barnes shown in the Rotary News email is also listed on THIS ARTICLE (http://money.cnn.com/2003/09/22/pf/autos/pedestrian_safety/index.htm) in CNNMONEY as being a "spokesman for Mazda North American Operations".

Gee -- maybe thats as good as being on "Mazda Letterhead" ;)

I am not real familiar with the dyno-testing process or car engines in general. I somehow seem to have a knack for fixing them though. Anyway... does it not matter that the car is just sitting still when being dyno'ed? If I recall correctly, from a Mazda mechanics video on the 8, at high load/HP/RPM conditions, an additional engine air intake port opens up. The air is fed from the front-end scoops. Seems that speed would effect the amount of airflow being forced into the engine. No airflow, no power. What is wrong with this assessment? Is the airflow change due to speed negligible? Do other engines have additional ports that open up like the RENESIS?

Thanks for any responses.

Zoom-zoom.

The only thing that still nags at me is the question of in-car dyno type devices e.g. G-Tech. They appear to indicate a similar torque curve as the chassis dynos. If the ECU issues with wheelspin, etc were totally to blame for lower-than-expected chassis dyno numbers then you would expect in-car dyno numbers to look better.

jds

Originally posted by mullogutherum
Note that:

(1) Mazda USA apparently arrived at their revised 238 HP figure after chassis dyno testing of 11 production cars. The results were then passed through a roomful of lawyers. In light of their latest statement, just how accurate could the revised figure be?

(2) If you read the statement carefully, the circumstances which can generate "considerable horsepower loss" are by no means limited to chassis-dyno-like conditions. Indeed, fuel enrichment and timing retardation appear to occur under any "heavy load acceleration". The latter term isn't defined, but nothing in the statement specifically precludes the power loss from arising in normal operation of the vehicle.

Agreed.

Who watched "Ed" (american sitcom) last night about the guy selling puppies as pure breds? Of course they were mutts, he offered to return people's money after a week. Well, guess what? Of course, no one took him up on it. It's the old puppy dog close (the first sales technique taught...). Mazda has mastered it.

The similarities between the Miata and the 8 goes beyond their having the same maunfacturer and producing less-than-advertised horsepower. Sorry to say it but the 8 is a Miata: handles great, but underpowered. Why do you think there are 20 rx's at just one of the local dealerships? There are people that LOVE their Miatas..many have dropped $K's on mods though.

The "explanation" of dyno'ed HP seems far too simplistic. What 16-year old wrote it? Why did it take Mazda a year or more to figure out/admit that the US-spec car was making less than announced?

Hmmmm.

Silver8,

I hope the 8 turns out like the miata. It'll be another fun to drive, lightweight, good handling, lots of potential, loved by its owners, easy to mod, reliable car. I've never met a miata owner that didn't love thier car.

Underpowered? Put on a turbo, that's what they're for. The RX7 was capable of huge amounts of power. The new Renesis, with it's improved port design will be able to make more power than the RX7 ever did.

Originally posted by silver8
It's the old puppy dog close (the first sales technique taught...). Mazda has mastered it.

the 8 handles great but underpowered.

The "explanation" of dyno'ed HP seems far too simplistic. What 16-year old wrote it?

Why did it take Mazda a year or more to figure out/admit that the US-spec car was making less than announced?

silver 8, stuff it. i've got my eye on you, and you're taking the thread off topic.

...not only that, but you're wrong. if you need me to count the ways, PM me, and i'll enlighten you.

Originally posted by silver8

Why do you think there are 20 rx's at just one of the local dealerships? Because perhaps that dealer is one of the many refusing to sell an 8 for MSRP or below?

Originally posted by GoBerserk
Silver8,

I hope the 8 turns out like the miata. It'll be another fun to drive, lightweight, good handling, lots of potential, loved by its owners, easy to mod, reliable car. I've never met a miata owner that didn't love thier car.

Underpowered? Put on a turbo, that's what they're for. The RX7 was capable of huge amounts of power. The new Renesis, with it's improved port design will be able to make more power than the RX7 ever did.

RX-8 lightweight at 3000 pounds? I don't think so. Shed 200 pounds and then we're talking. I mean, it's as heavy as a WRX with all it's AWD under there. Maybe lightweight when compared to the porker 6 at 3200 pounds for the V6...

:D

Originally posted by O.R.A.
RX-8 lightweight at 3000 pounds? I don't think so. Shed 200 pounds and then we're talking. I mean, it's as heavy as a WRX with all it's AWD under there. Maybe lightweight when compared to the porker 6 at 3200 pounds for the V6...
Actually the 8 really is lightweight, especially for a four door.

Now, start talking about cars like the BMW M3 that weighs around 3300 and the Audi S4 that weighs in at near 3900 lbs...

I'd love to hear Paul Yaw and canzoomer's take on this development. Both these guys have a ton of knowledge and the resources to come to their own conclusions ... Yaw made some comments about 10 days ago that support this "position" from Mazda.

Guys?

Nobody has brought it up explicitely in this thread yet, but what about concerns of acceleration at WOT as elaborated upon in the RN article?

As indicated in the WOT acceleration post in here, people have reported their cars accelerating faster at partial throttle than at WOT. I borrow the quote:


I've had other cars where this effect was perceptible also, but not to this extent. Typically the modern ecu goes "open loop" under WOT conditions which means a rich mixture, but this MAP seems richer than most.


I guess it would take cold data to compare it to other cars in an objective sense, but some people seem to take notice despite the RN articles mention of how the "driver should not notice", which may (subjectively) suggest more of an effect when compared to other cars.

Also curious to me is how it retards timing along with the richening of the mixture (is that the scoop on "open loop"? as per my reply in the parallel thread in general discussion, I still dont know why this is necessary on a vehicle equipped with a knock sensor - seems like overcaution). Do all performance-oriented cars that recommend/require premium fuel do the same?

And the other question, as far as getting power back...wouldn't it be at least as much of a question of leaning out the mixture as it would be keeping the ECU from retarding the timing? Wouldn't you not have to worry about the effects of a lean mixture at retarded timing on a cat if you didn't retard the timing?

Open loop means, in the general sense, no feedback system. In the sense of the ECU and fuel delivery, in closed loop mode it monitors air/fuel ratios via the O2 sensor and adjusts the mixture so as to keep the ratio at a certain level...generally this is done to maximize fuel economy at cruise. At WOT (I don't actually have to press the gas all that far to end closed loop operation on my FD, I don't know if that is the same as other cars or not) the O2 sensor doesn't react quickly enough, so the ECU goes open-loop and reads from its pre-programmed maps. This doesn't necessarily imply that the maps are rich, but usually there will be some margin of safety in there. As for the knock sensor, its reacting to something bad that has already happened...its not predictive, it is designed to simply keep the bad thing (knock) from continuing to happen, and pray that the first instance didn't break anything. You wouldn't want to use lean maps with no safety margin and rely on the knock sensor to save you.

Sorry if I'm rambling about stuff that is common knowledge...

jds

Originally posted by blizz81
Nobody has brought it up explicitely in this thread yet, but what about concerns of acceleration at WOT as elaborated upon in the RN article?

As indicated in the WOT acceleration post in here, people have reported their cars accelerating faster at partial throttle than at WOT. I borrow the quote:


I've had other cars where this effect was perceptible also, but not to this extent. Typically the modern ecu goes "open loop" under WOT conditions which means a rich mixture, but this MAP seems richer than most.


I guess it would take cold data to compare it to other cars in an objective sense, but some people seem to take notice despite the RN articles mention of how the "driver should not notice", which may (subjectively) suggest more of an effect when compared to other cars.

Also curious to me is how it retards timing along with the richening of the mixture (is that the scoop on "open loop"? as per my reply in the parallel thread in general discussion, I still dont know why this is necessary on a vehicle equipped with a knock sensor - seems like overcaution). Do all performance-oriented cars that recommend/require premium fuel do the same?

And the other question, as far as getting power back...wouldn't it be at least as much of a question of leaning out the mixture as it would be keeping the ECU from retarding the timing? Wouldn't you not have to worry about the effects of a lean mixture at retarded timing on a cat if you didn't retard the timing?

3000 is a lot of weight. I'm still trying to figure out where they put it. But compared to simliar cars out there today it's pretty decent.

The are only two production cars out there that I know of with acceptable weights, are the miata, and the elise, at 2300 and 1600 lbs respectively.

I wish car manufacturers paid more attention to enthusiasts. Mazda is pretty good about it. At least they paid attention to weight when they designed the 8 (carbon prop shaft). But when I get mine it's going to be pretty bare. No heated seats, no naviagtion; I don't want to lug that garbage around with me everywhere I go.

Originally posted by wakeech


silver 8, stuff it. i've got my eye on you, and you're taking the thread off topic.

...not only that, but you're wrong. if you need me to count the ways, PM me, and i'll enlighten you.

Keech:

First off, pound sand.
Secondly, save your breath (or key strokes), you might need them some day.

Weight comes from extra bracing for those suicide doors, + extra space/body for the rear seats.

Some of it is triple layer steel w titanium coating + extra bracing. Looking at all the light stuff they used (ali rear doors, boned, carbon prop etc) I'm suprised it came out as heavy as it did tho.

Cant compare it to the elise tho, thats VERY minimal. alu bathtub body, with a VERY light/small engine (new toyota 190 USis getting is 50kg hevier than the k1.8), no ABS, no airbags, no power steering, no gadgets (air con, powered windows). Nothing.

Just engine, chassy, brakes/wheels/drivetrain etc. Not quite as minimal or light as some of the 7 clones (Caterham R series is 400kgish, or under 1000llb).

The Elise only has 120bhp standard, but still has a higher power/weigh to the 8. But it is very hardcore, and I dont expect lotus to sell that manu federal Elises realy, even with 190bhp and aircon.

Sorry if I'm rambling about stuff that is common knowledge...


Yeah, I apologize for not heading to the web to read up about open loop and making you ramble. The thread was beginning to wander around a bit anyway, but that's no excuse.

Really my concern again is just a comparison of how much the timing is retarded and how rich the a/f gets under situations like WOT accel, with other performance-oriented cars. Like I mentioned in general discussion, another case of waiting for the CAN readers :) But listening to people say "The difference of the car backing off from partial throttle to WOT is more than previous cars I have owned" is tempting to take into a discussion.

(Me being one of the people that's purely satisfied with the overall power of the 8. Just concerned about things like the effect on driving feel and adjustments and having the most control out of the car's performance. If that means being more linear on the gas, so be it).

I hate to be crude, but doesn't it bother anyone else that this gives lots of technical loopholes and sidesteps and fun facts.. but doesn't actually give ANY answers whatsoever? Not to mention brings up several other concerns...

Is the engine really so borderline that it has to constantly choke itself to keep from predetonating?? If even in it's stock form knocking is such an issue, what about when we start throwing aftermarket stuff on it and the ECU can't keep up, suddenly we have a bunch of toasted rotaries on our hands?

Except the JDM models don't seem to have this issue.. is their gas REALLY that much higher octane?

Also, from the way it's worded (and people have mentioned this before, I know) I would assume the ECU is doing this ALL THE TIME, not just on a dyno. A "high load" condition doesn't have anything to do with what gear your in or how fast you're moving. All it means is the engine is doing a lot of work! So what they're basically saying is that the ECU doesn't just choke on a dyno. It chokes essentially any time you have the gas pedal to the floor.

Finally.. chassis dynoing IS a fairly accurate science, just in a different way than engine dynos. Most performance people prefer the chassis dyno because it gives a more REAL number of how fast you can expect the car to go, because it is measuring the amount of work actually being applied to the ground, after all the power required to run the drivetrain and accessories is shaved off the top. Noone's trying to get 238hp on a chassis dyno, they're trying to get a number at the wheels that is decent relative to that. You can predict fairly accurately what the wheels horsepower should be based on engine horsepower.. and 180 at the wheels either means that the engine is underpowered, the driveline is HORRIBLY innefficient, or the ECU is messing with it.

In the case of the ECU, they haven't really given us any reason to believe that the conditions that occur on a dyno don't also occur on the street.

I dunno.. don't mean to be harsh, but to me it just seems like a diversionary tactic is all. Again I don't doubt the RX8 is a great car and plenty quick, but so is my prelude and IT only puts out 195 horsepower. with an extra 30 it would be just plain fast!

I really don't want to stir up much trouble, I just get impatient because big parts of me really want this car, but my sensible, logical side says to hold out for answers, and then ALL my sides get impatient :P

I think its a totally valid concern Tresch. Your right when you say this gives Mazda alot of escape goat options. Honestly they've already adjusted the numbers once by 4.8% exactly and now their saying its impossible to dyno the car. This along with the seemingly high load crap, well I guess that takes this car right out of track and any kind of racing events because those sure as hell will be putting a "high load" on the car. Sigh I really like this car, but I want answers that can be verified by a 3rd party and not mazda.

Originally posted by Tresch
A "high load" condition doesn't have anything to do with what gear your in or how fast you're moving. All it means is the engine is doing a lot of work! So what they're basically saying is that the ECU doesn't just choke on a dyno. It chokes essentially any time you have the gas pedal to the floor.

I dunno.. don't mean to be harsh, but to me it just seems like a diversionary tactic is all. Again I don't doubt the RX8 is a great car and plenty quick, but so is my prelude and IT only puts out 195 horsepower. with an extra 30 it would be just plain fast!

I really don't want to stir up much trouble, I just get impatient because big parts of me really want this car, but my sensible, logical side says to hold out for answers, and then ALL my sides get impatient
Originally posted by poison123
This along with the seemingly high load crap, well I guess that takes this car right out of track and any kind of racing events because those sure as hell will be putting a "high load" on the car. Sigh I really like this car, but I want answers that can be verified by a 3rd party and not mazda.
I'm no scientist, but my common sense (maybe not so common?) tells me that the "high load" would be related to the amount of inertia that needs to be overcome to get from a lower speed to a higher speed. Therefore, how "hard" you accelarate will affect how much load is on the engine, and as you get closer to the desired speed, the load would be decreasing. Also, the car applying "high load" system settings would be so quick that you would not really sense all this going on. Obviously, this would mean that the car does not "choke essentially anytime you have the gas pedal to the floor", as stated by Tresch.

Originally posted by Tresch
In the case of the ECU, they haven't really given us any reason to believe that the conditions that occur on a dyno don't also occur on the street.
What do you mean? In the opening post of this thread, they just stated a whole list of reasons that conditions on the dyno are different than those on the street. Did you forget already?

My suggestion to Tresch and posion123 is to go test drive the 8. If it pleases you and you like it, buy it. If it doesn't, don't. How hard is that?:D :cool:

Anyone want to ship over a container of our 93 octane to Japan and see what they get with their ECUs?:D

Originally posted by javahut


[B]What do you mean? In the opening post of this thread, they just stated a whole list of reasons that conditions on the dyno are different than those on the street. Did you forget already?



Not true. They give a whole list of reasons why "[t]here is no true way to generate flywheel horsepower from a chassis dynamometer". But they state only *one* clear difference between conditions on the dyno and conditions on the street: "[o]nly the rear wheels are turning while the front tires remain stationary." (Or did you forget already?)

The condition which provokes fuel enrichment and timing retardation is simply described as "heavy load acceleration". As Tresch states, there is no reason to believe that this does not occur on the street.

What do you mean? In the opening post of this thread, they just stated a whole list of reasons that conditions on the dyno are different than those on the street. Did you forget already?

Also, don't forget the part about the DSC. they explain that with DSC, it does these certain engine management stuff. In that thinking, then the cars that are totally base without the sport or GT options, should be dynoing much higher numbers! Another hole in the theory. There are just too many holes. Nothing concrete. Lots of theory but no practice.

Then, as poison mentioned, there's the 4.8% thing.. that REALLY gets my skin crawling...who wants to take bets that mazda will lower it another 4.8% when the current return deal runs out? :P

My suggestion to Tresch and posion123 is to go test drive the 8. If it pleases you and you like it, buy it. If it doesn't, don't. How hard is that?

I have! And I like the car for a lot of reasons, but I WILL admit, that as far as top end power, it didn't really seem to pull any harder than my Prelude, which is a 195 horsepower car. Granted, the torque curve was MUCH nicer, because on the RENISIS, the torque piles on thick and quick! Making that 159 ft/lbs seem pretty crazy! where on the prelude you don't get a good kick until you hit VTEC at 5,400 rpm.

But with all honesty, the VTEC is still pulling HARD up to the redline.. where the RENISIS felt like it just fizzled out.

I would love to do both a drag race side by side, AND a ROLL ON race side by side between the cars. My estimation is that the RX8 will win the drag by a decent margin, because of the RWD, limited slip diff, and 6speed gearbox advantages.. but in a roll on from about 40 miles per hour.. I bet the two cars would be pretty even, with perhaps a slight nod towards the RX8.

Frankly, if it really put out 238 crank hp... the RX* should CREAM the prelude in any straight line test.. but I just don't think it would.

Don't get me wrong, I love the car, but if I'm going from a 15,000 dollar loan to a 30,000 dollar loan, I want to make it worth my while! I like going fast. if I drop that much money, I want to be going faster than I am now.

The trouble is, the RX8 is the ONLY CAR ON THE MARKET that meets my other requirements! It's a 4 door SPORTS CAR. how cool is that? I don't want an EVO or STI.. some souped up junky econo sedan.. I want an all out ground up tiny lightweight rear wheel drive sports good that looks nice, is comfortable, and has easy rear seat access. But I also want it to go FASTER than my current car! hehehe.. *sigh* I'm just too picky :P

Originally posted by Tresch
I don't want an EVO or STI.. some souped up junky econo sedan.. I want an all out ground up tiny lightweight rear wheel drive sports good that looks nice, is comfortable, and has easy rear seat access.

OFF TOPIC: You just called for trouble.....:D

Haha, ok ok.. well I apologize to any STI/EVO owners out there, it was a bit of an exaggeration.. but it's pretty widely known that neither of those have any spec of LUXURY in them. (though to be honest, I've never sat in an EVO) They're crazy fast.. but they're not crazy NICE. Different people have different priorities! I wouldn't look down on someone at all for wanting an EVO. they're badass.. just not what I want.

If you really can't see enough of a difference between your Prelude and the RX-8 to warrant the price difference, I think you answered your own question... the RX-8 is definitely not for you.

On the other hand, if you have any kind of feel for sport driving... not just who will win a "staight line race" (although there's no way a Prelude would even come close), the RX-8 is soooo much more than the Prelude has ever been or ever will be. Frankly, your comparison between the two is so absurd, I don't know why I'm even posting a reply. I guess my typing fingers must be restless.

"On the other hand, if you have any kind of feel for sport driving... not just who will win a "staight line race" (although there's no way a Prelude would even come close), the RX-8 is soooo much more than the Prelude has ever been or ever will be."

I'm making the assumption right off the bat that you've never driven a prelude. I'm all about the corners.. in fact, I autocross my prelude regularly.. so do all my friends. In fact, a friend of mine, driving a prelude in STS, is currently leading not just his class but the entire REGION by PAX. KTHXBYE :)

Really though, don't knock it till you've tried it. The 'lude is a highly underestimated car. In fact, it's WEAKNESS is straight line performance, which is exactly WHY I made this particular comparison. If the RX8 isn't much faster than a car that frankly isn't that good in a straight line.. there's gotta be a problem.

Once again though, I don't want to dig myself too deep, because I HAVEN"T put them back to back, only used my comparitive butt dyno. Which says "RX8 has smoother and stronger low end, but prelude seems to pull as good or better at the top"

*shrugs* so.. please.. don't make accusations and judgements on other people's character from single comments on forums. Where did I ever say I only cares about straight line performance? Nowhere. This is what turns threads into flame wars. Just a tip

I made no character accusations. Almost anyone who is into any type of handling, cornering, "road racing" knows that a front wheel drive car does not compare. There's no front wheel drive F1 or CART for a reason.

true, but being RWD does not instantly make a car handle good, nor does FWD instantly make a car handle bad. A prelude will out turn a base mustang any day of the week. And I bet a CRX with custom suspension could probably even take the 8 in cornering.

I'm just saying stay open to things. Just because it's FWD does not make it instanly a horrible performing car. Trust me, one of the big reasons I want the 8 is BECAUSE it's rear wheel drive. I'm just saying that if I'm doubling my car payments I want significant improvement in all areas. straightline AND cornering.

Anyway, this is going off topic. I'll shut up now!

Originally posted by rotarynews.com


Read RotaryNews... " Mazda has backed [our] hypothesis up with a release of information."

IE, from Mazda...

If you don't beleive so then see the attached screen shot from my inbox.

So, our standing is backed up by actual automotive engineers from Japan. Thereby proving that we know what we are talking about.

Doesn't Mazda have a spokesperson or a PR person....people keep using "official" word from Mazda....shouldn't it be undersigned 'Mazda' and not the name of an employee....? just curious........

I happened to own a 2000 prelude......and I did luv it!........once the revs got up there it was fun to drive..........but come on?......it was no where close to being as fast as the 8, or have the handling capabilities...........both are great cars, but sometimes I shake my head at some people on here?........the prelude was clocked at 0-60 in 7.4secs using a hard launch........I think it was actually a little less, but this is no where close to the 8......and the balance of the car did not compare to the 8.............but yes I still miss it............if you drove it hard enough, the V-tec would kick in and surprise anyone who wanted to race..........but the 8 would be too far ahead for that to matter!...........I honestly wonder why people on here are unhappy or complain about the 8?.........it is one of the best cars I personally think for the $$........and not much slower than the 350Z which I test drove twice......and the styling makes heads turn....I think we are all lucky to have one..........or have one on order!!!.........

Yeah, I'm getting close to buying an 8 every day :) I drive too many people around for the back seat in the lude!

Btw, my 'lude has a suspension kit, which overcomes a lot of the handling issues, heh.. maybe I should have mentioned that :P

official numbers: 0-60 in 6.7 and 1/4 mile in 15.2 seconds. that's with front wheel drive, open differential, 5 speed, and less effective torque curve. If it was a RWD, LSD, 6speed... it would probably be closer to a 6 second 0-60 and would easily be in the 14s in the quarter.. i.e: around the performance of the RX8. I'm not saying the RX8 doesn't perform better, I'm just saying that for the amount of power mazda claims, it just seems TO ME like the difference should be bigger, that's all.

but hey! I could be wrong. maybe I should just test drive the damned thing again... and have my friend in my car beside me, heh.. when they get the test drive car in at the dealer.. i'll take it for a longer ride then last time.

-Tresch

And if pigs could fly... ;->

(c'mon you had to see that coming)

Originally posted by Tresch

official numbers: 0-60 in 6.7 and 1/4 mile in 15.2 seconds. that's with front wheel drive, open differential, 5 speed, and less effective torque curve. If it was a RWD, LSD, 6speed... it would probably be closer to a 6 second 0-60 and would easily be in the 14s in the quarter..

Originally posted by bureau13
And if pigs could fly... ;->

(c'mon you had to see that coming)



Don't you mean if trolls could fly

I love the "my car is faster, and my friend is the fastest of everyone" posts in threads like these. makes me laugh for about 2 seconds.

Originally posted by Tresch
I hate to be crude, but doesn't it bother anyone else that this gives lots of technical loopholes and sidesteps and fun facts.. but doesn't actually give ANY answers whatsoever? Not to mention brings up several other concerns...

Absolutely right. a lot of talk, not much lucid reasoning around here.

Is the engine really so borderline that it has to constantly choke itself to keep from predetonating?? If even in it's stock form knocking is such an issue, what about when we start throwing aftermarket stuff on it and the ECU can't keep up, suddenly we have a bunch of toasted rotaries on our hands?

No. The reason it is running rich has bugger all to do with detonation. They are using extra rich mixtures to make the burn hotter in the exhaust pipe, and this makes the catalytic converters work more efficiently on CO to CO2 conversion.
Another factor on this is that the cats are a long way back down the exhaust pipe.
Some cars have them right close to the head exhaust ports.
With the cats as far back as we see on the RX-8 they may be fighting a problem with this. With regards to detonation, if you have knock happenening, it is already too late. The damage, especially on a rotaries seals , is already happening if knock starts.


Except the JDM models don't seem to have this issue.. is their gas REALLY that much higher octane?

No, it is the same as we get here.
The system in most of the world is to rate gas by the RON number.
That is the Research Octane Number. RON is a measure based on tests performed under low severity conditions.

There is also the motor Octane Number (MON)
MON is determined by testing under severe load conditions.
As neither is reflective of all conditions, the standard used in North America is a blend of these ratings.

In North America we use a rating called PON, for Pump Octane Number (also called Road Octance Number by some oil companies who want to further obfuscate the issue).
To determine PON, you use the following formula:
(R+M/2).
That is to say: RON+(MON/2)
Generally RON numbers are about 3 to 5% higher than PON numbers.
So, a world RON number of 95 is roughly equivalent to a PON of 91 or 92.
NONE of these standards are about how much power is available from burning the fuel. These are all about what at what compression and timing levels detonation (knocking) will occur.
Some brands of fuel use high aromatic content additives to boost the anti knowck index, and this has a side effect of also maming more power. Chevron, for example, uses what they call "Techron"
Techron is a fancy name for light aromatic solvent naptha.
See:
http://library.cbest.chevron.com/lubes/chevmsdsv9.nsf/0/121f9e914042ad46882563a2004f1c78?OpenDocument
Other additives that raise the AKI actually reduce the power available from the fuel. A classic example of this is ethanol alcohol, in a 10% mix with gasoline. This is also sold as "gasahol" or "winter oxygenated fuel" it is alos popular as it substantially reduces some emissions levels, especially in winter.

Both methods prevent the occurence of knock. But one provides more available power, while the other reduces power.
One may also use readily available Xylene or Toluene to increase the AKI, Octan rating and make better power. However the carcinogenic properties of these are rather horrible.

See:
http://www.motorcycle.com/mo/mcnuts/fuelron.html
http://www.refiningonline.com/EngelhardKB/crep/TCR4_29.htm
http://www.medfordfuel.com/octane.htm
http://www.shell.ca/code/motoring/encyclopedia/info/jargon.html

Also, from the way it's worded (and people have mentioned this before, I know) I would assume the ECU is doing this ALL THE TIME, not just on a dyno. A "high load" condition doesn't have anything to do with what gear your in or how fast you're moving. All it means is the engine is doing a lot of work! So what they're basically saying is that the ECU doesn't just choke on a dyno. It chokes essentially any time you have the gas pedal to the floor.

Actually, what I am hearing is two possible scenarios:
1) The claim that if the front wheels are not turning at the same speed as the rear, then the ECU, which obtains rpm numbers from all four wheels, assumes the car is in a loss of traction situation, and tries to stabilize the car by reducing power.
2) The ECU sees this condition, and assumes a sensor fault has occurred, and adjusts to "safer" fuel/air mix settings, reducing power as a side effect.

I dispute this. We measured the sensor load and outputs on the wheel sensors. When the DSC is disabled, the ECU is not receiving any signal from the wheel sensors.
The final proof that this is not a valid issue is the fact that cars in Japan, which have the same ECU and sensors, but with a different fuel air map installed, regularly produce dyno rear wheel HP of 210 to 215HP.
This is consistent with an engine making over 240 to 250HP.
In Canada and the USA similar dyno runs show an output between 170 and 185HP, which is consistent with an engine making 200 to 215HP.


Finally.. chassis dynoing IS a fairly accurate science, just in a different way than engine dynos. Most performance people prefer the chassis dyno because it gives a more REAL number of how fast you can expect the car to go, because it is measuring the amount of work actually being applied to the ground, after all the power required to run the drivetrain and accessories is shaved off the top. Noone's trying to get 238hp on a chassis dyno, they're trying to get a number at the wheels that is decent relative to that. You can predict fairly accurately what the wheels horsepower should be based on engine horsepower.. and 180 at the wheels either means that the engine is underpowered, the driveline is HORRIBLY innefficient, or the ECU is messing with it.

As mentioned above the one simple fact that makes the claims about the ECU changing the performance on a dyno is that JSpec RX-8's make exactly the power output on a dyno that we would expect. This show that we can expect the car to dyno normally if the DSC is disabled, and it also shows a comparative difference of around 35HP between Japan and here.
247-35 is 212.
238-35=203
220-35=185
205-35=170


In the case of the ECU, they haven't really given us any reason to believe that the conditions that occur on a dyno don't also occur on the street.

Exactly. More to the point is that Japan cars dyno as expected. Why would ones over here NOT dyno normally?

I dunno.. don't mean to be harsh, but to me it just seems like a diversionary tactic is all. Again I don't doubt the RX8 is a great car and plenty quick, but so is my prelude and IT only puts out 195 horsepower. with an extra 30 it would be just plain fast!

I really don't want to stir up much trouble, I just get impatient because big parts of me really want this car, but my sensible, logical side says to hold out for answers, and then ALL my sides get impatient :P
You are not stirring up trouble.
There are basically 3 factions in this discussion:
Those who are seeing the facts and accept them, and wait to hear more.
Those who do not care about the facts, they just love the car and their feelings are hurt if you say anything to imply it is less than they were led to belive.
Those who work for, or make a living from Mazda, and who toe the "party line" because to do so would risk their positions with Mazda.
It is awfully easy to read the postings and see which category each person fits.

Forthose who say I am whining, I wish to disagree.
I want to determine the facts.
Not the PR messages. We already know those are either provided by idiots or liars. I can see Mazda making a mistake when they said the Miata was 165HP.
I could see two mistakes when they said the RX-8 was 250HP.
After all, the general American response to other measurement systems is not uncommonly one of disregard: "Who need that funny metric system?"

But the idea that after all this they still did not actually know how much power the engine makes in emissions legal settings?
No way, Jose.

In the final analysis we had hoped Mazda would fix the problem. It is clear that they are not doing so.
As RX-8 owners we have three choices in this matter:
Live with it
Fix it
Give the car back to Mazda.

I fall into the middle category. I spent a modest amount of time and money investigating if it was possible to fix it, and determined to my satisfaction that this is not too hard, so I decided to keep the car. The other issues like the heat, AC, oil pan baffles, floor mats, block heaters, and so on are either being addressed by Mazda, or are easily remedied by our own efforts.
These are typical new model teething pains. Many other cars have far worse issues than this.

In addition to the project I am working on, I know of at least 3 other companies or parties working on similar ECU replacement or reprogramming approaches, so I am quite confident that I will own an RX-8 that performs to spec, in both HP and fuel economy ,in a short time period.

That is good enough for me, so today I sent Mazda Canada a letter stating that i have changed my mind, and will keep the car.
The PR person I spoke with was very positive about this, we discussed what some of us owners are doing about it, and he applauded our efforts.
Somewhere up high in Mazda management a decision maker sits, who is more interested in covering his ass, and in burying their liabilities and costs than in delivering what was promised.
While that may hogtie the engineers at Mazda from delivering what was promised, it does not make it impossible, or even very difficult to get what we wanted.
And it is still a lot cheaper than buying another car with similar features and performance.

The car is a bargain, even at 200HP.

250+HP at a cost of an extra $2000 is a steal.

Bravo, Canzoomer! I was very interested to read your research about the ECU and DSC inputs, and agree with your approach to investigate alternatives and solutions. Welcome back to the fold ;) , and please keep us in the loop with your investigations and results! (I'm in the wanting to know all info category, by the way :D)

Regards,
Gordon

Originally posted by canzoomer
As RX-8 owners we have three choices in this matter:
Live with it
Fix it
Give the car back to Mazda.

I fall into the middle category. I spent a modest amount of time and money investigating if it was possible to fix it, and determined to my satisfaction that this is not too hard, so I decided to keep the car. The other issues like the heat, AC, oil pan baffles, floor mats, block heaters, and so on are either being addressed by Mazda, or are easily remedied by our own efforts.
These are typical new model teething pains. Many other cars have far worse issues than this.

In addition to the project I am working on, I know of at least 3 other companies or parties working on similar ECU replacement or reprogramming approaches, so I am quite confident that I will own an RX-8 that performs to spec, in both HP and fuel economy ,in a short time period.

That is good enough for me, so today I sent Mazda Canada a letter stating that i have changed my mind, and will keep the car.
The PR person I spoke with was very positive about this, we discussed what some of us owners are doing about it, and he applauded our efforts.
Somewhere up high in Mazda management a decision maker sits, who is more interested in covering his ass, and in burying their liabilities and costs than in delivering what was promised.
While that may hogtie the engineers at Mazda from delivering what was promised, it does not make it impossible, or even very difficult to get what we wanted.
And it is still a lot cheaper than buying another car with similar features and performance.

The car is a bargain, even at 200HP.

250+HP at a cost of an extra $2000 is a steal.

"I love the "my car is faster, and my friend is the fastest of everyone" posts in threads like these. makes me laugh for about 2 seconds."

Hey man, it sounds stupid but it's true. MUST DEFEND MY CARS HONOR! Hehehe.

Canzoomer:

you rawk

canzoomer........are you still trying to hold on to the image or belief the car does not produce 238hp??.............come on.........it was already clear from the release why the dyno results are showing less power............and with the 0-60 times and 1/4 times times from all the different sources, the car produces at least 230+hp,...........everything makes sense........but it does lack in the 5-60 times..............anyway, I commend your efforts......and would luv to find a way to get 250+hp......but the car is just fine the way it is.........and to the guy who had the prelude at 0-60 in 6.7..........you wish..........every mag out there that tested the car had 0-60 in no better than 7.4secs...........

No, you are mistaken.
I don't. The facts do!

As you are sailing down denial, watch out for these!

As long as canzoomer sticks around we'll make progress. I'm glad you're sticking around 'zoomer!!

Originally posted by canzoomer

We measured the sensor load and outputs on the wheel sensors. When the DSC is disabled, the ECU is not receiving any signal from the wheel sensors.
The final proof that this is not a valid issue is the fact that cars in Japan, which have the same ECU and sensors, but with a different fuel air map installed, regularly produce dyno rear wheel HP of 210 to 215HP.

What you are saying sounds similar to what jmanalov posted about Sport Compact Car finding in their GTech testing with sensors disabled. It now really does sound like Mazda is just throwing out techno babble to hide the real cause.

In addition to the project I am working on, I know of at least 3 other companies or parties working on similar ECU replacement or reprogramming approaches, so I am quite confident that I will own an RX-8 that performs to spec, in both HP and fuel economy ,in a short time period.

Very good news indeed ! Can you be more specific? What kind of MPG gains to you expect? How short of a time period?

Certainly glad to hear canzoomer you decided to keep your RX-8, your observations are always read with interest.

Of course will the reprogrammed ECU's meet emissions tests that more and more states are starting to impose.

As far as I know, plans are in the works to run the RX-8 on a 4 wheel dyno (where the front roller is linked/driven by the back roller), and to run on a regular dyno with a code reader in place to see if the engine is indeed going into a safe mode. There's also the issue of the Japanese ECU code, and seeing if our ECUs were re-flashed with that code if we'd get more power. I haven't heard of anyone having any luck in that front, however.

Regards,
Gordon

Originally posted by javahut
There's no front wheel drive F1 or CART for a reason.

Yeah, the rules do not allow it.

You're just playing dumb right? You don't really think if new rules were set up that expressly allowed this configuration, people would be racing to use them do you?

jds

Originally posted by O.R.A.


Yeah, the rules do not allow it.

Originally posted by nk_Rx8


What you are saying sounds similar to what jmanalov posted about Sport Compact Car finding in their GTech testing with sensors disabled. It now really does sound like Mazda is just throwing out techno babble to hide the real cause.

I do not know with certainty.
All I know is what I read and hear, just like everyone else.
If people in Japan get dyno runs over 210HP, however, I doubt that this is really an issue..

Whther it is down 5HP or 50 from what is claimed I can say that at the top end I definitely feel that is down on power, and i believe that can be improved.

Originally posted by rxeightr


Very good news indeed ! Can you be more specific? What kind of MPG gains to you expect? How short of a time period?

Certainly glad to hear canzoomer you decided to keep your RX-8, your observations are always read with interest.

Nothing too specific yet. Once we are done I will report what we have done.
I am hoping to gain at least 2MPG on use with higher rpm ranges.
On cases where people baby it a bit and keep it down in the lower rpms ranges i doubt it will change mileage much.

We are focusing on what happens above 6000rpm.
The time period is a bit uncertain.

We hope to achieve some results in the next week that I can report on with facts and dyno figures.

There is a season ending drag race in my area next weekend. They have some categories for admission by amateurs , and if we can get enough done in time we will enter my car for the sake of curiousity.

As far as making something suitable for others to install, the biggest challenge is the ECU connectors.

We know what company makes them, but I do not have any information yet as to availability. That will be fairly critical, as we plan to make the unit plug in between the ECU and the harness leading into it. That way it can be installed with wrenches and screwdrivers and without permanent modifications.
For doing a prototype we do not need proper connectors, but as a production item it will be necessary.
The rest of the components we are using are parts that are on the aftermarket already.

Originally posted by poison123
Of course will the reprogrammed ECU's meet emissions tests that more and more states are starting to impose.

We are aiming to be legal under Canadian emissions rules. They are similar to some US states.

For some it will not pass the tests. California, for example.

Originally posted by O.R.A.


Yeah, the rules do not allow it.

no, the rules don't allow it but the only advantage it MIGHT offer the teams who decided they want to fatten up, weigh down, and complicate their already fragile and complicated machinery are the ones way way at the back thinking they can get a better start using traction control and 4WD/AWD. after that, there is NO advantage to using 4WD/AWD. end of discussion.

Cons:
- it's expensive, thus far undeveloped, drive mechanisms complicated, would disrupt the modern structure of the chassis (and all incumbent aerodynamic concessions you see on all modern cars), and also heavy, increasing both sprung and unsprung mass, decreasing the ability to ballast the car (and set it to the right balance)

Pros:
- at the start might gain a car ~1.0s on the first lap at best, to later be passed as their wholly inferior car can't keep up.

don't even try to say that this comprimise is worth looking into, even if it was in the rules.

Excellent news, Zoomer, both on the wheel sensor front, and the fact that you are keeping the car!

You are eminently qualified to work on the ECU issue, and I am sure we can look forward to a fix.....(though we may have to learn 'Linux' to use it!...;) )

One point to consider is that the system may be receiving inputs from an accelerometer. If it has one, it would be located at the 'centre of rotation' of the chassis, in the console between the seats.....
.
.
.
doc

Originally posted by Doctorr
Excellent news, Zoomer, both on the wheel sensor front, and the fact that you are keeping the car!

You are eminently qualified to work on the ECU issue, and I am sure we can look forward to a fix.....(though we may have to learn 'Linux' to use it!...;) )

One point to consider is that the system may be receiving inputs from an accelerometer. If it has one, it would be located at the 'centre of rotation' of the chassis, in the console between the seats.....
doc

Thanks Doc!

As far as the Linux part goes, that should be no major problem. Hard Data Ltd. is the first company in Canada selling computers with Linux pre-installed, since 1993.
Matter of fact almost all our business is Linux based.
http://www.harddata.com/
http://www.linux.org/vendor/company/0015.html
http://www.google.com/search?q=Maurice+hilarius+Linux

As far as a chassis acceleromoter, I guess it is possible, but i feel that it is fairly unlikely.
The wiring diagrams do not show one.

I bought the Mazda RX-8 wiring manual ( it is a separate manual from the shop manual and cost me $125).

Canzoomer,
I have read all your various posts with very much interest.
I for one, pegged you as a "whiner", but now it seems you know what you are talking about! I apologize, it just seemed that you originally were so sarcastic and cynical. Now you are channeling your energies the right way!

I have decided to give the car back, mostly because I don't want to drive it in the winter, and..... hope that all the issues, horsepower, mpg etc are solved by the spring. I do love this car and will probably get another then.

Keep up the good work.

It's a shame that Mazda has handled this all so poorly. Let's hope they eventually learn from all of this.

BTW, what do you do for a living? You seem to know much more than most of us.

Thanks for the kind words Rotarian.

I think that whether you keep this car, or buy another later, you will sooner or later end up with an RX-8, as you obviously like it a lot.
I understand, as I do too.

I was what you call a "whiner" because I was hoping to persuade a lot of people to make enough of a stink with Mazda to motivate them to DO something.
That did not work, so now on to Phase II: "Do something myself".

As for what I do?

I am the president of a company that designs, manufactures and supplies computer equipment.
Most of our equipment is sold to Universities and government/military institutions for research, computational work, etc.
We also build a line of mass storage servers from 1 to 6 TerraByte capacity data storage filesystems.

My background is in electronics, computing, metal fabrication and design, and my hobbies are computers, A/V, cars, pets ( tropical fish, reptiles, etc), travel, cars and bikes, motorsports, and soccer.

I try to keep busy!

As for what I know, well, I am a hardware hacker, I confess. Whether it is computers, cars, satellite, audio and video, I love to take things apart and make things i think up.
Due to the nature of my business and my travel hobby i import and export a lot, hence the reason i am importing Mazda Japan and Mazda Speed parts..
Everything I have learned on the RX-8 has been from reading, the Web, and talking to other people. I have several friends with RX-7's, and have owned an rX-3 many years ago.

I also do not like Mazda Canada a lot, as I have had dealings in the past with them on a few cars, and the service, parts, and warranty issues are a repetitive nightmare.
My son is in the middle of fixing his 1996 Mazda Millenia S ( the one with the Miller Cycle engine with a supercharger) and he has had his first experience with Mazda, and their parts prices and issues.

Take a look at our webite for some info on our computer gear..
http://www.harddata.com

Sorry to say Mazda engineers are misleading Rotarynews and all of you!

Who are they kidding?

first of all, if the DSC (similar to Acura's VSA on my CLS) is disabled (turned off), it will not affect the ECU in anyway. The article also agrees with this fact.

Second, like any modern car the ECU after seeing a a 100% load (or WOT) will rich the mix of the fuel. Then, the ECU will lean it as the air is coming to the engine. No secret about that, any Dynojet with Wideband O2 sensor will show you the A/F mixture.

Also, if the the engine is chocking of air, ( like if there is no Huge fan in front the engine to keep it from overheating and keep decent supply of O2) the knock sensor will retard the timing. This is true if you are on dyno or running on hot summer day. Slipping the rear or if the front are stationary has nothing to wiht that!

However, Mazda in their article mentioned Catalic Conveter and Exhaust temprature... It is not about knock sensor, it is all about limiting emissions to please the EPA.

Again why the JDMs RX-8 dyno 200+ SAE WHP?!!

Nashua.

and the wideband O2's on the dynojet measure post cat readings.

Your engine ecu primarily relies on the pre-cat readings.

I should have readings from a pre-cat wideband O2 setup (with data logging to a laptop) in a few days. We'll all see just how rich these cars are running.

Originally posted by syntrix
and the wideband O2's on the dynojet measure post cat readings.

Your engine ecu primarily relies on the pre-cat readings.

I should have readings from a pre-cat wideband O2 setup (with data logging to a laptop) in a few days. We'll all see just how rich these cars are running.

True, But any OBD-2 scanner will read the O2 sensor voltage. If this is not enough as you mentioned replace the ore-cat stock O2 sensor with a Wideband O2 sensor and have the voltage read and ploted.

Nahsua

Why are people having such a hard time with this? The E46 M3 has had the same "feature" for like the past 3 years, this is really nothing new...

Originally posted by NashuaCLS


True, But any OBD-2 scanner will read the O2 sensor voltage. If this is not enough as you mentioned replace the ore-cat stock O2 sensor with a Wideband O2 sensor and have the voltage read and ploted.

Nahsua

Where did I mention obd2?

It's a whole new O2 outside of any factory O2, with a digital reader.

This is not an autometer gauge tapped into the factory O2, not obd2 readings.

It's a true wideband that is going to be welded into the stock pipe before the cat., with some electronics that read the values (not a gauge).

Originally posted by syntrix
and the wideband O2's on the dynojet measure post cat readings.

Your engine ecu primarily relies on the pre-cat readings.

I should have readings from a pre-cat wideband O2 setup (with data logging to a laptop) in a few days. We'll all see just how rich these cars are running.
We have done that.
It is quite rich.

Originally posted by bureau13
You're just playing dumb right? You don't really think if new rules were set up that expressly allowed this configuration, people would be racing to use them do you?

jds



Of course I'm kidding, but my point is that RWD does not a sports car or performance car make. For example, I've driven a bunch of different Porsche 911's and I am convinced that you need to drive them almost like a FWD car if you want to get the most out of them on a track.

Yeah, this is not the case with the RX-8 and this is one of the reasons why I've been racing Miatas for years, but anyway, just echoing what Tresch was saying about being open minded. Go back to your regularly scheduled issues about apparent missing power and lousy explanations from Mazda people.
:)

Originally posted by canzoomer

We have done that.
It is quite rich.

Good, then start tuning! I'm going down that path.

Nice posts Canzoomer.

Keep up the work!

Vince

So, having gone over NEARLY EVERY fricking device in the RX-8 shop manual and wiring manual, and having digitally metered most of them , we can now say:

1) There is no accelerometer in the car

2) There IS a barometric pressure sensor.

3) The ABS and DSC may be completely disabled by removing the fuse #12 on the fuse block.
This is a 60A fuse, B/L color code.

4) There are 4 wheel speed sensors, used for ABS and DSC.
Removing the fuse not only disables the ABS/DSC and wheel sensors, but also disables the circuit to the ECU.
The ECU throws no fault code when this is disabled.
The ECU does not change fuel or ignition output modes under slippage or varying wheel speed conditions when this is disabled.
One may easily leave these systems on, and using a programmable pulse generator feed in a false signal on the front wheel sensor harness plugs. This also does not affect ECU readings, fuel or ignition outputs.

The DSC off switch takes the DSC off the ECU circuit when pushed once.
It is not necessary to hold and disable the switch. While this does disable it, this is for safety purposes only. It stops the DSC from working until the ignition is switched off, whereas the single short push works in the same fashion, but allows it to be turned back on again. There is no functional difference between thetwo states, except that in the "long hold" mode it can not be turned back on again.

There are only 2 only conditions that can provide feedback to the ECU, when used in conjunction with the DSC and the wheel sensors, that would possibly affect the DSC and cause it to reduce power:

One is the steering angle sensor, which is not activated until we pass about 40% ( or more) turn in either direction.
IF we achieve 40% or more turn, and IF the DSC is enabled, then a signal is sent to the ECU.

The other is the rear wheels. When they turn in substantially unequal amounts ( wheelspin), then the DSC sends a signal to the ECU, which will reduce the power output.
It also looks for front wheels being turned, and if so can reduce power output.

If the wheels are turned more than 40%, and if the rear wheels turn at greatly unequal rates, then the ECU will adjust the ignition and fuel to reduce power output. When the rear wheels resume turning at the same rate, then the DSC signals it is back to normal, and the ECU returns the ignition and fuel to normal states for the throttle level and rpm range.

There is no correlation whatsoever with the front wheel speed sensors and the DSC. They only work with the ABS system.
There is a wheel turn sensor which will trigger the ECU to reduce power if the rear wheels slip unequally. It will reduce even more if the front wheels are turned a lot.

So, if you want to dyno an RX-8, feel free to keep the DSC on, or off, as you wish. Just do NOT turn the wheels, and do not spin the rear wheels on the rollers.

To be absolutely sure , you may remove the fuse for the ABS and ECU circuits, and then the sensors are absolutely inert. The car drives normally, just with no ABS or DSC.


So, Bern: I am calling "BS" buddy!

6) For those who have the headlight washer system, and want to disable it, it is motor driven, and the fuse is on a 20A fuse, #19 in the fuse box.

7) For those hooking up the rear low fog light, it is a 10A fuse #20 in the fusebox.

8) For those with Xenon HID headlights, the auto-leveling system is active, not just gravity driven, and has a front and rear leveling sensor, and two powered actuators, one for each headlight.

9) For the front fog lights, if one wants to make them work without the low beam being on, but with the park lights on, one needs to move one wire which comes from the foglight switch, and bypass the headlight relay.
The connection on this can be accessed at the fuse box.
The front fog light relay is module # E5-01

10) Tuning for power and economy:
Apart from the usual mass-air sensor, the RX-8 incorporates a barometric pressure sensor. Adjusting the output from it to the ECU has a significant effect on ignition timing and fuel injector flow rates as regulated by the ECU. I suspect that running at low baro and low humidity can make a significant difference in power output. At a GUESS maybe 10hp. Running a high baro pressure, at or below sea level, with high humidity, will result in more power output.
There is also a standard anti-knock sensor. When it is triggered the ignition is retarded by about 2 degrees. on the leading plugs, but nothing on the trailing plugs.
This has surprisingly little effect on the power output. I guiess that due to the dual spark plug setup the burn does not change much from this. It also means that running lower octane fuel should have little effect on power, but will have an effect on fuel economy.

More to come. If anyone has specific wiring and logic/sensor questions, fire away!

great info canzoomer, so if someone were to completely disable abs and dsc by pulling a fuse, a dyno would read the hp properly correct?

It sounds to me like what he's saying is if you aren't cranking over the steering wheel while on the dyno (and why would you?) it should be reading properly whether you pull the fuse or not...right? Did I misread something? I'd love to be corrected, because frankly I find this a little disturbing.

jds

Originally posted by SuperRex
great info canzoomer, so if someone were to completely disable abs and dsc by pulling a fuse, a dyno would read the hp properly correct?

Originally posted by bureau13
It sounds to me like what he's saying is if you aren't cranking over the steering wheel while on the dyno (and why would you?) it should be reading properly whether you pull the fuse or not...right? Did I misread something? I'd love to be corrected, because frankly I find this a little disturbing.

jds


Yep, it pretty much says unless the wheel is cranked over or the wheels are slipping on the dyno rollers, it should read correctly. Which means Mazda is still not telling the whole story. It's starting to look like all those who were suspicious of the technobabble in that unofficial official Mazda explanation may be correct in feeling that way.

Great info Canzoomer -- from a real world perspective I must say that the car acts very differently with the DSC totally disabled (hold button down) versus just clicked off. The DSC will definitely grab the back end when on. With it clicked off -- I get good wheel spin to a point and then the system will kick in. With it disabled you can do some really crazy things. :D Based on your info this doesn't seem to make sense. You are saying there shouldn't be any difference between click off and totally disabled :confused:

Very interesting Canzoomer, keep up the good work!

Vince

Originally posted by RXhusker
Great info Canzoomer -- from a real world perspective I must say that the car acts very differently with the DSC totally disabled (hold button down) versus just clicked off. The DSC will definitely grab the back end when on. With it clicked off -- I get good wheel spin to a point and then the system will kick in. With it disabled you can do some really crazy things. :D Based on your info this doesn't seem to make sense. You are saying there shouldn't be any difference between click off and totally disabled :confused:
They both do exactly the same thing. They turn off the logic circuit that the DSC uses to tell the ECU to cut power.
Wheelspin at the rear wheels is the key. The DSC detects wheelspin, and it then tells the ECU. The ECU cuts power.
If the DSC is off then the ECU does nothing about it.

The difference in performance you see is when the ECU cuts power, it does not turn it back up again instantly. It waits a while.
So, on a hard launch, if you spin a tire for a moment, then it takes about 3 seconds to return to full power.

As for differences in the 2 modes, I don't meant to be critical, but I suggest it is psychological.

WRT the turned wheels, if wheelspin is detected, the ECU will not return full power until the wheels are straightened.

Originally posted by RXhusker
You are saying there shouldn't be any difference between click off and totally disabled :confused:

And why would an additional icon light up on the display (the little swerving car with skid marks), after holding DSC in versus just pressing once, if there was no functional difference between the two?

Canzoomer:

Your information needs to be in it's own post so it doesn't get lost in this "official" post.

Vince

Originally posted by javahut


And why would an additional icon light up on the display (the little swerving car with skid marks), after holding DSC in versus just pressing once, if there was no functional difference between the two?

Sorry to jump in, but there is a functional difference: think of it as Pausing and Stopping a movie.

If you believe your DSC is faulty, you can switch it off permanently until you restart the car (this is the best example that comes to mind.) - Most likely this might be done by a technician while performing some sort of diagnostic on the car or system. My guess..

Originally posted by javahut


And why would an additional icon light up on the display (the little swerving car with skid marks), after holding DSC in versus just pressing once, if there was no functional difference between the two?
Maybe I did not express it clearly enough:
Press the button briefly and the one light goes on, and DSC is disabled.
If you want to turn it back on press the button AGAIN.

Press and hold for over 5 seconds and it is turned off until you re-start the car.

Originally posted by canzoomer

Maybe I did not express it clearly enough:
Press the button briefly and the one light goes on, and DSC is disabled.
If you want to turn it back on press the button AGAIN.

Press and hold for over 5 seconds and it is turned off until you re-start the car.

Not just that, but the DSC will come back online if the ABS kicks in (I assume just for the ABS time?) - only way to stop it is a long press.

Uh... yeah... I got that. So you're saying they have an icon on the display and the only thing it is signifying is that I can no longer re-enable DSC until I turn the car off and back on?

Originally posted by RobDickinson
Not just that, but the DSC will come back online if the ABS kicks in (I assume just for the ABS time?) - only way to stop it is a long press.

Wouldn't the DSC disabled indicator go back off if the ABS was causing DSC to come back on?

Hey Canzoomer,
While your pouring through the logic of this car can you take a moment to look at the tire pressure sensor circuit? I would really like to know how to disable it for the times when I am using wheels without sensors. Thanks and keep up the good work!

Canzoomer: It only takes one fault to go into safe mode. I appreciate you going through the motions of checking the traction system, but that is only one that we know of could be triggered to make it run rich on the dyno.


I'm calling your BS flag, and raising you a Exhaust Temp sensor.

--dan

Originally posted by canzoomer

Maybe I did not express it clearly enough:
Press the button briefly and the one light goes on, and DSC is disabled.
If you want to turn it back on press the button AGAIN.

Press and hold for over 5 seconds and it is turned off until you re-start the car.

Forgive me, but I'm not quite following - I was of the impression that the one button controlled two systems:

- the quick push disabled the DSC stability control system, with it's own indicator light. Another quick push re-enables DSC.

- The long push additionally disabled the separate traction control system, with it's separate traction control indicator light (the car with two rubber streaks behind it). DSC and TC can not be re-enabled without cycling the ignition of the vehicle.

Thoughts on TC separate from DSC?

Thanks,
Gordon

Originally posted by canzoomer


4) There are 4 wheel speed sensors, used for ABS and DSC.
Removing the fuse not only disables the ABS/DSC and wheel sensors, but also disables the circuit to the ECU.
The ECU throws no fault code when this is disabled.
The ECU does not change fuel or ignition output modes under slippage or varying wheel speed conditions when this is disabled.
One may easily leave these systems on, and using a programmable pulse generator feed in a false signal on the front wheel sensor harness plugs. This also does not affect ECU readings, fuel or ignition outputs.

The DSC off switch takes the DSC off the ECU circuit when pushed once.
It is not necessary to hold and disable the switch. While this does disable it, this is for safety purposes only. It stops the DSC from working until the ignition is switched off, whereas the single short push works in the same fashion, but allows it to be turned back on again. There is no functional difference between thetwo states, except that in the "long hold" mode it can not be turned back on again.

There are only 2 only conditions that can provide feedback to the ECU, when used in conjunction with the DSC and the wheel sensors, that would possibly affect the DSC and cause it to reduce power:

One is the steering angle sensor, which is not activated until we pass about 40% ( or more) turn in either direction.
IF we achieve 40% or more turn, and IF the DSC is enabled, then a signal is sent to the ECU.

The other is the rear wheels. When they turn in substantially unequal amounts ( wheelspin), then the DSC sends a signal to the ECU, which will reduce the power output.
It also looks for front wheels being turned, and if so can reduce power output.

If the wheels are turned more than 40%, and if the rear wheels turn at greatly unequal rates, then the ECU will adjust the ignition and fuel to reduce power output. When the rear wheels resume turning at the same rate, then the DSC signals it is back to normal, and the ECU returns the ignition and fuel to normal states for the throttle level and rpm range.

There is no correlation whatsoever with the front wheel speed sensors and the DSC. They only work with the ABS system.
There is a wheel turn sensor which will trigger the ECU to reduce power if the rear wheels slip unequally. It will reduce even more if the front wheels are turned a lot.


This makes NO sense at all. How can the traction control work by taking the difference between rear wheel speed - we have a limited slip differential that tries its damndest to eliminate rear wheel speed differentials.

All traction control devices in existance work by comparing wheel speeds of the front tires to the wheel speeds of the rear tires - the difference is how much the drive tires are spinning. It then looks at the throttle and brake positions to determine what is going on - basically are the rear wheels spinning due to power or are they "spinning" because the front wheels have locked up causing the wrong signal. The only other way I have ever heard about it being done is in Formula 1 when TC was banned - then the teams used barometers in the air intake to get the pressure and correlate it with maps to approximate a speed.


I don't understand the logic that you state activates the DSC (i'm assuming your including traction control in DSC?). Are you saying its rear wheel slippage AND 40% steering angle? If this were the case, it would never activate on a burnout (just try doing a burnout with DSC on - its not happening) since the wheels are straight. If it was either of the signals alone, the DSC would be going off when you turn into a parking spot.

A true DSC program takes all 4 wheel speed sensors and steering wheel angle. From the 4 wheel sensors it can calculate a yaw rate of the car. It then compares this calculated yaw rate to the yaw rate supplied by the steering wheel angle - if they don't match there is trouble. This data is then compiled with input from the traction control system. You now have steering, throttle, brake, and all 4 wheel speed information running into the same system. Accelerameters are also quite popular, but not necessarily needed.

Also, I can guarantee you my DSC has gone off due to loosing the rear end while off the throttle with steering inputs much less then 40% already.

Originally posted by Speed Racer
Hey Canzoomer,
While your pouring through the logic of this car can you take a moment to look at the tire pressure sensor circuit? I would really like to know how to disable it for the times when I am using wheels without sensors. Thanks and keep up the good work!
I was not concerned as we in Canada did not get this feature included on our cars.. But, I feel your pain..

OK, let's have a peek..
The TPMS uses an RF sender in each wheel.
These send to sensor receivers in the wheel well area.
No separate fuse is shown for this system (bummer).
It is wired in the same harness as most of the dash area sensors and connections, so isolating the wire is tricky.

The wiring all feeds to the TPMS control module, which is under the dashboard, behind the centre console panel.
Labelled C2-01
To get at it one has to dismantle the centre console area ( the area that holds the audio system, temperature controls and optional NAV system).
I think disconnecting that module is your best bet.
It has an 16 terminal connector, with 5 wires in it used.
The wires are colored L/R, B/Y G/B L/W on the top row, and a single wire coded B on the bottom row.

Code legend for colours:
L=Blue
R=Red
B=Black
Y=Yellow
W=White
L/R means a Blue wire with a Red stripe.

Good luck!

Originally posted by Gord96BRG


Forgive me, but I'm not quite following - I was of the impression that the one button controlled two systems:

- the quick push disabled the DSC stability control system, with it's own indicator light. Another quick push re-enables DSC.

- The long push additionally disabled the separate traction control system, with it's separate traction control indicator light (the car with two rubber streaks behind it). DSC and TC can not be re-enabled without cycling the ignition of the vehicle.

Thoughts on TC separate from DSC?

Thanks,
Gordon
No apologies needed. It is a complex set of systems. The wiring manual is 169 Pages!!

However, there is NO TC system.
The systems are ABS and DSC (Dynamic Stability Control)

There is no subsytem called or anything that mentions a traction control (TCS).

For DSC there are sensors that monitor rear wheel slippage and front wheel turn angle past 40% turn.

The ABS monitors the 4 wheel speed sensors.

Pressing the button briefly disables the DSC, unless it is triggered by ABS signal, whereby it re-enables (Thanks to somebody for that tip about the ABS re-enabling the DSC, you are correct).

Holding the button in competely disables the DSC, ABS input or not, and keeps it off until the car is turned off and back on again.

One can also produce the same result with disconnecting the battery and reconnecting it.
Until the DSC is re-calibrated it stays off. This is because it needs to recalibrate the wheel position sensors.
The sensors are not proportional. They are simple switches.
They send a signal once the front wheels are past 40% turned. They stop sending the signal when the wheels turn back to centre, inside of 40% turned.

Originally posted by pr0ber


This makes NO sense at all. How can the traction control work by taking the difference between rear wheel speed - we have a limited slip differential that tries its damndest to eliminate rear wheel speed differentials.

We have a differential that Mazda describes as a "Super LSD"
It corrects the slippage, but is not instant.
In addition it does not completely equalize the turn speeds, or it would not be a "differential"
What is does is limit the slippage when it exceeds a predesigned amount. It is still quite possible to slip a wheel to a certain degree. When the slippage is above turning radius differences, the measurements from the wheel sensors tell the ECU that a rear wheel is slipping. Above tha tpoint the DSC will certainly try and correct the condition.

All traction control devices in existance work by comparing wheel speeds of the front tires to the wheel speeds of the rear tires - the difference is how much the drive tires are spinning.

All is a strong word. This one does not. One can disable the front wheel speed sensors (unplug them from the harness) and there is no DSC fault. There IS an ABS fault of course!
If one disables the REAR sensors one gets a DSC fault, however.

It then looks at the throttle and brake positions to determine what is going on - basically are the rear wheels spinning due to power or are they "spinning" because the front wheels have locked up causing the wrong signal. The only other way I have ever heard about it being done is in Formula 1 when TC was banned - then the teams used barometers in the air intake to get the pressure and correlate it with maps to approximate a speed.

There is a pressure sensor on the RX-8, but it is used to allow for calibration of the Mass Air Sensor readings to be adjusted for air pressure.

I don't understand the logic that you state activates the DSC (i'm assuming your including traction control in DSC?). Are you saying its rear wheel slippage AND 40% steering angle?

No, it is a small degree of rear wheel slippage, combined with front angle, or a greater degree of rear slippage with no front turn angle.
It allows more rear slip if the wheels are straight. This is balanced with the amount of wheel speed differential caused by going around a corner. Remember, it is a differential unit!

Also, I can guarantee you my DSC has gone off due to loosing the rear end while off the throttle with steering inputs much less then 40% already.
Interesting. Possible cause may be one rear wheel sliding, so it slows down it's turning rate.
I wonder how it is correcting if you are "off the throttle" as you describe? It corrects slip by reducing throttle. That is why it is horrible on a track. When cornering hard, under throttle, you induce oversteer. If you back off the throttle you go into understeer, which can cause the front end to "wash out" and slide.

I have no static way to test for that condition.

In any case, I am looking at the engine, running at a constant throttle pedal position and rpm, and then enabling and/or disabling sensors, measuirng their outputs, and the resulting changes to ignition and fuel injection. Much of what i have said is interpolation from these tests.
Our goal is to increase power and mileage, mainly focusing on the rpm range above 6200rpm.
I simply tested the condition to determine if something "clever" in the ECU was defeating our tuning.
We did the tests static (on a dyno) and in the car on the road.
With DSC disabled while on the road we got the same readings as when static in the garage. Small differences in the Mass Air Sensor readings were detected, but that is due to air flow coming in the engine air intake. BTW, the stock intake system is quite good. it achieves about a 20% extra boost at 100kmh compared to standing still.
If somebody wants to build a cold air intake for this car and gain much, they are going to have to be very good at what they do. The stock setup has very little resistance.

"BTW, the stock intake system is quite good. it achieves about a 20% extra boost at 100kmh compared to standing still."

Are you alluding to some sort of a ram air effect going on here? Could this be where some of the missing HP is on the static dynos? For instance, if top speed is 136 mph (as some forum members have claimed to have reached), could Mazda be measuring top HP at that speed, thereby deriving the benefits of the increased air flow?

Please excuse my ignorance if my question evidences an abundance of it.

OK, got our main part of work on the fuel injection system mapping done.
Still have to do the ignition mapping.
Results so far:
Gain of 24.5HP at 8,000rpm
Gain of 11.3Ft/lb of torque at 5750rpm
This is on a Mustang dyno.

This is still using very conservative figures for richness/mixture.
No chance of knock on 91 octane gasoline.

Will be doing a fuel economy highway run tonight.

Will be doing ignition mapping in the next few days.

We feel we can pull another 10-15HP out of this with gentle settings.

At the present the emmissions level is still legal in Canada and 48 us states.
we would not pass the California spec.
It does not run clean enough inside of 5 minutes. Takes about 15 minutes to fully warm the cats enough to pass CA levels.

Originally posted by vandal
"BTW, the stock intake system is quite good. it achieves about a 20% extra boost at 100kmh compared to standing still."

Are you alluding to some sort of a ram air effect going on here? Could this be where some of the missing HP is on the static dynos? For instance, if top speed is 136 mph (as some forum members have claimed to have reached), could Mazda be measuring top HP at that speed, thereby deriving the benefits of the increased air flow?

Please excuse my ignorance if my question evidences an abundance of it.

Not an expert, but most manufactures rate their engines based on a dyno in a building. If you get more horsepower due to ram air that is just a bonus.

canzoomer: what baseline are those hp numbers from (180?, or 200, 238) ?

or in better terms: what are the final/actual numbers you are seeing ?

BTW, keep up the good work. I'd offer help, but I don't have an RX8 (yet). I wish I knew more about these darned ECU's and how to hack them.

Dave

Canzoomer..

Sounds awesome. I would love to gain 30-40 HP without any permantent mods to the car.

I volunteer to be a pre-prod tester if you need. (I work on computers for a living, but don't know anything about hacking auto ECUs. Sounds like fun though).

Very nice work canzoomer. I missed what ECU you are using, what are you using?

Vince

Thanks for the offer guys..

Baseline I get on a Mustang Dyno is around 178HP (cold) and about 172 after some runs and heat buildup.

We did some more runs today, and started working on the midrange section, between 3700 to 6200
These are the areas where we run 4 out of 6 intake runners.
Surprisingly enough there is HP to gain in those ranges as well.
At the 6200+ we see it running way rich.
At 3700 to 5500 it is actually running too lean, which surprised me.
With a bit more fuel and some minor adjustments we are gaining 15HP in there as well now.
More importantly we see a gainof nearly 20 ft/lb of torque at 5000rpm.

We just started setting up the ignition controller, and will do some tests and runs on that tonight and tomorrow..

It is now dynoing around 204 to 210 HP on the Mustang dyno, at the rear wheels. The ECS is disabled from the dash.


I am hoping like crazy we get done for the weekend..
There is an amateur drag event going on at the local track and I want to try her out..

Originally posted by compaddict
Very nice work canzoomer. I missed what ECU you are using, what are you using?

Vince
Original ECU is in place( it does WAY too much to be replaced) but we are bypassing the fuel and soon the ignition outputs, and are using a separate fuel controller and just installed an ignition controller. We will be experimenting with the ignition shortly.

Off to play!

Keep us posted! Sounds like good results so far!

Since you are bypassing the fuel control and ignition, does this disable the DSC and cat protection circuits? How hard will it be to put it back to stock when you need service - I know its dishonest, but so is stealing our power.

I'd like to understand how dumping a ton of raw fuel down the drain helps the cat instead of clogging it.

I just don't buy that "protecting the cat" deal. They could have plugged an exhaust temp sensor near the cat and then mess with fuel/timing/throttle position, etc. if the temps got so high that the cat could be in danger. That's what other manufacturers do. Simple and effective.

It just looks like the MazdaSpeed Protege ECU maps all over again. The ECU maps in those cars go crazy rich when they switch to open loop. So bad that Mazda just came out with a reflash because a lot of people were complaining about hesitation when the car switched from closed loop to open loop and the car would bog down. The reflashed ECU also freed up some nice hp increases.

Originally posted by LL7
Since you are bypassing the fuel control and ignition, does this disable the DSC and cat protection circuits? How hard will it be to put it back to stock when you need service - I know its dishonest, but so is stealing our power.

We are allowing the DSC to continue to work. When the DSC cuts power, it causes the ECU ignition output to cut power. It does this by skipping signals to ignition. We are not altering that signal, except to change the timing of it. More or less advance as needed to make more power. If the signal does not exist we reflect that.

As for the "protecting cats" idea, I disagree with whoever came up with that. I believe they run them with richer mixtures to make more heat, so the cats work more efficiently, especially right after startup.. As I can not quote empirical evidence about that yet, it remains an "opinion".

On the cat issues, I do have a K-type thermocouple as well as the wideband o2 that I need to install.

Maybe this weekend I can get it all wired and welded on.

I can also data log to a laptop, so I should be able to generate some good graphs, and we can see just how hot the 8 is running.

Reply to previous Post

“I don't understand their use of the word "load" here. Surely, the load on the engine is the resistance it encounters as it attempts to turn the driveshaft. This would be a function of the weight of the car and the gearing (and at high speed the aerodynamic drag). So in the real world (as the weight is constant) high load simply means being in a high gear.

Are they saying that it will only produce maximum power in low gears?

And what about "the load quickly diminishes as the car accelerates in each gear". I don't understand that statement at all.”


I am a novice at this posting bit, but will add what I hope will be some help to the understanding of the above.

“Load”, is as you stated the resistance to the rotation of the drive shaft. When under acceleration in a lower gear, putting the weight of the vehicle into faster and faster motion is the load the writer was referring too. The load is reduced as the rpm begins to peak. This is a curve if it were to be charted. On the front side of the curve is the maximum load because this is where the greatest rate of velocity change takes place. As you go over to the back side of the curve and the rate of velocity change begins to decrease the “load” becomes less until a steady velocity is maintained due to no more RPM being available. At this point, “steady velocity,” the only load is then aerodynamic drag. All of this assumes the vehicle is being operated on a perfectly level even textured surface.

In the larger gears, aerodynamic drag becomes more of a factor. If you had a large enough gear where the engine rpm could not reach its RPM limit and the velocity became steady, say 200 + mph, you would have reached the point where engine thrust (Horse Power) would be exactly equal to the opposing aerodynamic drag and friction losses through the drive train. Then if there was a way to know the value of both drive train losses and aerodynamic drag, actual engine horse power could be calculated for that specific operating condition.

Very interesting

An 1983 Rx7 SoloII Driver

the cat, catylises oxygen. they need to see the proper amount of oxygen in the exhaust to be happy. they want to see a 14.7:1 air fuel ratio. if you give it more oxygen it will get too hot and burn up. the cat is not bothered by a rich mixture, in fact they can use that to cool it off. misfires are also bad, misfires = more oxygen. so the way to keep the cat happy is to not get it super hot, and not have any misfires. and if you get it hot you can dump fuel in there and cool it down

i think this is right, ive been doing a lot of reading to try and find out how to make a cat live, so this is inferred from anywhere i could find info, which is scarce at best

mike

Originally posted by canzoomer
We are allowing the DSC to continue to work. When the DSC cuts power, it causes the ECU ignition output to cut power. It does this by skipping signals to ignition. We are not altering that signal, except to change the timing of it. More or less advance as needed to make more power. If the signal does not exist we reflect that.

As for the "protecting cats" idea, I disagree with whoever came up with that. I believe they run them with richer mixtures to make more heat, so the cats work more efficiently, especially right after startup.. As I can not quote empirical evidence about that yet, it remains an "opinion".

Great work so far Canzoomer. I believe the richer mixtures do lower the heat in the cats though. Liquid fuel lowers combustion temps by the condensing effect yes?

Brian

Originally posted by Buger


Great work so far Canzoomer. I believe the richer mixtures do lower the heat in the cats though. Liquid fuel lowers combustion temps by the condensing effect yes?
Brian
Yes, at certain levels.

The big problem is the newer emissions specs that say the car has to be running within spec in 5 minutes.

If we look at the rpm ranges over 6200 we see it running way too rich.
Same below 3750

In the mid range they are actually running it too lean, to heat up the cats.

The thing about the stock fuel maps that really surprised me was this midrange lean setting.

Going in we expected to see overly rich mixtures. As a result we hoped to gain higher rpm power.
When we discovered that the midrange was low, and we actually gained about 12 to 15 hp in there as well by enrichment it surprised us a lot!

In this they are likely leaning that range to ensure heating within 5 minutes to meet the testing requirements.

Anyway, no testing again until Monday. Burned out my coil packs on ignition testing.
Turned out that the Mazda coil packs are designed for a VERY short dwell and charge time. We were running them too long duration, and they melted!

Before they did we saw some interesting things. Pulled like a train. We were doiing our dyno runs in 3rd gear up to then, but we had to switch to 4th as we were actually running up the revs too fast to be easily controlled, and needed a higher gear to make the dyno tests less touchy. We were actually breaking the tires free in 3rd!

We are up an additional 12HP by raising the timing 1.5 to 2 degrees at 6200rpm and up. We are avoiding adding advance below 5,000 as that is the range you would risk knocking.
Although with the enrichment we added in the midrange it is still pretty unlikely..

That is 45+HP gained at 8000rpm, and most interestingly up 32HP at 5700, which is roughly the torque peak point. Torque was up 26 ft/lbs as well at 5700.

Out of all this we see:
Fuel controller alone will get us back the power we are missing.
In doing so we are still at levels to be legal in 48 states and Canada

With an ignition controller (I ordered in one with tunable charge and dwell timings!) we should be able to safely pull around 220-225HP at the wheels, which is probably around 260+ HP at the crank.

BTW, coil packs cost about $95 Canadian each.
sigh..

Originally posted by vandal
"BTW, the stock intake system is quite good. it achieves about a 20% extra boost at 100kmh compared to standing still."

Are you alluding to some sort of a ram air effect going on here? Could this be where some of the missing HP is on the static dynos? For instance, if top speed is 136 mph (as some forum members have claimed to have reached), could Mazda be measuring top HP at that speed, thereby deriving the benefits of the increased air flow?

Please excuse my ignorance if my question evidences an abundance of it.

No ignorance. A very good question.
The gain of ram air effect is pretty well wasted with the stock intake and exhaust. We did some road runs as well as dynos early this week, and we saw little difference between the two.

We have been using a pressure sensor inserted in the intake and in the later stages of the exhaust, and were interested in this as my next step after the engine tuning may be intake and exhaust.
I think the stock intake system is pretty well matched to the stock exhaust system.

What we saw was that intake pressure DID increase quite a bit at about 100kmh. Power did not go up. This tells me that there is a flow restriction. Probably mainly in the exhaust.

I have not done anything yet about it, but next tests on that would be things like removing the air filter, removing the rear exhaust section, and testing on the dyno and road.
By doing that we can easily guage what gains (If any) we could expect with better exhaust and intake systems. I am really doubting we will see too much change with just the intake though. Speaking bluntly, most people think a car is running faster when they hear intake howl. Often however the change in power is minimal. It usually takes both intake AND exhaust to make a real difference. Good news here is that there is tons of room at the rear to install a good free flowing exhaust system.
I am thinking some mandrel bent pipe and a pair of long Magnaflows will likely do the trick. Maybe remove the stock resonator and put in a longer one as well to keep the sound levels down..

:D

You are one crazy Canadian! This is quite exciting, I wonder what the remapped ECU plus an exhuast and intake would do?

Originally posted by Digisan
:D

You are one crazy Canadian! This is quite exciting, I wonder what the remapped ECU plus an exhuast and intake would do?
I don't know until we try it, but the "seat of my pants" says I think we can hit 240HP at the wheels if we do it right.
While it won't be a Mustang Cobra killer, it will surprise a few people with 350Z's and so on..

I doubt we can break too far into the "280HP Club" unless we look at going beyond naturally aspirated.

Let's start the whole "Turbo versus Supercharger" debate off with a bang.
I think that a blower is a natural for the RX-8. There is very little room to cram a turbo in to the exhaust, but a blower would just drop right in place in front of the engine. And the nice thing is that it is an easy "bolt in" mod which could be removed for dealer service and warranty issues. Remember, with our "free" warranty services we will want to do any mods in an easily removed manner!
With a 10:1 compression ratio we would not want a lot of boost, but about 4 to 6 lbs would do lots for low and midrange, and probably put us to 300HP quite easily. Then you won't get sand kicked in your face by those nasty RX-7 3rd Gen owners!

Originally posted by canzoomer
Then you won't get sand kicked in your face by those nasty RX-7 3rd Gen owners!

Heh, I doubt 300bhp in an rx-8 will trouble a 280bhp rX-7 but its better than nothing :)

Keep up the good work, even though I'm way to far away to benifit directly!

I agree, an SC seems like the best option. One thing that would bother me is the price. For 6 lbs of boost it should cost about $2K for everything, otherwise it wouldn't be worth it to me. I know that's not alot of money, then again it's not alot of boost. Also, the Jackson SCs aren't very cheap, about $2.5K each, they seem to be way overpriced IMHO.

D-san

Hey Canzoomer, are you planning on reselling, or providing any kind of products avaialble to your fellow RX-Comp8triates? With all the mapping and tuning work your doing, selling pre tuned, ready to drop-in parts would be interesting. I'd bite..

OverLOAD

Originally posted by Digisan
I agree, an SC seems like the best option. One thing that would bother me is the price. For 6 lbs of boost it should cost about $2K for everything, otherwise it wouldn't be worth it to me. I know that's not alot of money, then again it's not alot of boost. Also, the Jackson SCs aren't very cheap, about $2.5K each, they seem to be way overpriced IMHO.

D-san
Well, you get what you pay for..

The Jacksons are full kits. That adds up

Don't forget an intercooler is probably going to be necessary as well at 6 lbs..

I figure a full setup with blower, intercooler, plumbing, pulleys, cooling for the blower unit, and a boost controller will likely cost around $3,000

Originally posted by OverLOAD
Hey Canzoomer, are you planning on reselling, or providing any kind of products avaialble to your fellow RX-Comp8triates? With all the mapping and tuning work your doing, selling pre tuned, ready to drop-in parts would be interesting. I'd bite..

OverLOAD


So would I.

Originally posted by OverLOAD
Hey Canzoomer, are you planning on reselling, or providing any kind of products avaialble to your fellow RX-Comp8triates? With all the mapping and tuning work your doing, selling pre tuned, ready to drop-in parts would be interesting. I'd bite..

OverLOAD
Hell yes!

That IS the plan. We will be selling a bolt in fuel ( and maybe ignition, we will see) controller for the RX-8.
I expect to have them available by the end of October. I am not paying for all of this just for fun!
I have to get some money back on my investment.
Do you know what 100+ hours of dyno and tuning shop time costs??

The slowest item for our builds to come in are the connectors to allow you to just plug it in to your ECU's sockets.
We have to use matching male and female connectors to match the ECU, and then we run a harness out from that to the controller, which will be in an aluminum cast box.
Install will take about 15 minutes, as will removal.

We are targetting a fuel map setup like this to sell at around $1,000 and with ignition controller around $1500.
Late, we are contemplating a unit with multiple map capability for around $2,000 for the full kit.
If we manage to get enough numbers we could easily drop it down quite a bit, but for now I am basing numbers on 10 people buying it.
All prices stated are in Canadian dollars, so if you want US cost multiply by .75 ( $750, $1,125 and $1,500).
Taxes and freight extra. Shipping weight around 20 lbs.

With the multi-map setup we would provide at least 3 maps:
1) stock
2) NA tuned fuel and ignition.
3) boosted 6 lbs

Or something like this

We will also likely do a cat-back and mid pipe solution after that.

Feedback is welcome and definitely invited!

Awesome work, canzoomer!

About the car running within spec in 5 minutes: Why, do you think, would Mazda make the fuel maps that way for all temperatures and not do something simpler like having a "5 minutes from a cold start" map to warm up the cat and then go to a more conventional map?

I guess that there are other variables in the law that they need to also look at, but I'm just curious.


I'm also interested in your opinions on the car's behavior with the revised fuel and timing that you are optimizing. Things like part throttle behavior, traffic, around town driveability, etc.

This is really excellent work! I wish I was nearby and could help.

Originally posted by O.R.A.
Awesome work, canzoomer!

About the car running within spec in 5 minutes: Why, do you think, would Mazda make the fuel maps that way for all temperatures and not do something simpler like having a "5 minutes from a cold start" map to warm up the cat and then go to a more conventional map?

I guess that there are other variables in the law that they need to also look at, but I'm just curious.


I'm also interested in your opinions on the car's behavior with the revised fuel and timing that you are optimizing. Things like part throttle behavior, traffic, around town driveability, etc.

This is really excellent work! I wish I was nearby and could help.
I don't know why Mazda did this, but then I suspect this ECU map was a bit of a work in haste. Frankly it is awful.

Response on the road runs i have done gives me behaviour very much like before the mods. I t simply has more torque, way more power, and also I noticed we did not get the rough idle like the stock setup.

The biggest noticeable difference is at around 6200rpm.
Stock setup just falls of at 6200 when the intake opens all the way. It seems to pick up a bit as revs climb past 7000, but it only barely gets back to where it was before 6200.

With the remap you get a noticeable strong surge at 6200, and a smaller one around 7400rpm, and it builds hard with rpm. At 8000 it starts to level off and reaches peak at 8200rpm.
You get peak power within 2HP from 8000 to redline and beyond.

canzoomer,
thanks for the awesome work. I had a couple questions and comments.

1) I believe I understand the changing of the fuel map setup through the ECU. What are the changes to the ignition controller?

2) I thought you had said something about potential increases in fuel economy. Have you looked at that or run enough miles to see any changes there?

I would guess more than 10 people would be interested in buying this. If that would help drop the price and you would take debit cards, I have a feeling you could get alot of $500 debit cards from people.

dyno sheet?

First canzoomer.....Awesome work.
I would definately pay for your Fuel and ignition controller.
Some wish lists would be...
1)Easy install removal (sounds like you have that covered).
2)A way to switch between stock, stock ign + Fuel mapping, and Modded Ign + Fuel mapping.
3)A way to upgrade the Proms (I have access to Prom Programmers) or Flash, in case you find bugs that could cause severe problems (Pinging etc), especially for any of us early adopters.

My goals are probably not as radical as yours. I want to extract any SAFE extra performance without going to the point of needing to run race gas (92 octane pump). I don't polan to change intake or exhaust, I just want optimal performance.


Now a question:
Do you think that Mazda is running lean in the midrange to help produce better fuel milage for hiway cruising? (Is this a stupid question?)
Also, do expect MPG to suffer with your fuel mapping changes? Do you plan to do any MPG tests ?

Thanks for the work. Again I would gladly pay for all of your hard work. I would love to hear your 1/4 mile times soon to shut up the 350Z crowd that keep ragging on the RX.

Rick.

Originally posted by canzoomer
With the remap you get a noticeable strong surge at 6200, and a smaller one around 7400rpm, and it builds hard with rpm. At 8000 it starts to level off and reaches peak at 8200rpm.
You get peak power within 2HP from 8000 to redline and beyond.

Nice work! I'd buy one today if you were ready to sell it.

I would be interested in buying too, once proven safe.

What octane gas are you running when your doing this testing? Will you be making a map that will be safe with California Piss (91 octane)

-Chris

Would the AT see proportional results?

Another customer here if someone reliable in Wash. D.C. area to install & maintain -- may be simple, but not for me.

On the Sevenstock forum on this board, there is a topic about the comments by Mazda about dynoing the RX-8 and it showing less output and they talked to Mazda engineers at Sevenstock and I found this very interesting post by "jsotelo" straight from Sevenstock, which I will quote here:

Originally posted by jsotelo
Okay fresh from Sevenstock.. the RX-8 guys hit Mazda pretty hard with questions on HP.. and when you read between the lines this is what the deal is.

Mazda re-flashed the ECU to fatten the mixture. That seems to be it. They said they did it for a number of reason.. the biggest seems to be that new cars have to have a cat that lasts for 10+ years.. running lean will kill the cat before that so they had to change the map. Then they went into this crap about how hot the cat gets when running lean and starting fires but I don't buy that. It was also hinted that if you get ahold of a J-spec ECU it will plug and play and give you full HP.

The test cars the journalists used were running 100 octaine with the J-spec ECUs. The ECU will give mo powah with higher octaine.. or at least it did before they changed it. The Japanese Renesis guys freaked when they found out that Cali only has 91 octaine and told them to put in 100 for the tests.

Mazda says that you need at least 91 octaine to get good HP out of the car but it will run on 87 and the engine will de-tune itself to avoid detonation.

Mazda (inadvertatly) admitted to a fuel starvation problem on the track once you get to about 3/8 of a tank. They are working on a fix and it sounded like they had one before they basicly told the guy to shut up. Sounds like the pickup in the tank isn't in the best spot but you won't notice this in daily driving.. only track days.


So this explains a lot of things and it actually makes sense. It is obvious that the mixtures are really rich. We've seen that. We've also seen how cars running on 100 octane gas break into the 14's and post similar performance numbers as the "press" cars, but others don't.

Interesting about the fuel starvation at the track. I'm glad they are working on a fix.

It doesn't explain anything about the ECU behaving differently on a dyno. I think that part is simply made up. No one has been able to find evidence of this. All I see is that if you want to make "advertised power" you have to pump up the octane a lot.

All of this also makes me think that we should not be surprised if Mazda remaps the ECU to improve performance once they have more time to test different settings vs. exhaust temp and cat longevity. Like canzoomer said, I think that these fuel maps were done in haste. They had everything set and they got caught with some federal emission law problem and gave it a quick and dirty fix.

Like I said earlier, they seem to have done the same thing with the Mazdaspeed Protege, but the car was showing hesitation problems and so many people complained that they provided a "fix" in the form of a reflash and the reflashed cars show much better A/F ratios.

Originally posted by canzoomer
Let's start the whole "Turbo versus Supercharger" debate off with a bang.
I think that a blower is a natural for the RX-8.

ok fine. start up a new thread, please. we lost the old one (have NO idea where it went), so let's make a new one.

until later.
(turbo are t3h winnar)

Canzoomer,

First, great work! Second, how do your dyno plots look on the top end compared to stock? The torque curve probably doesn't drop like the stock one does, but I was wondering if it looks much smoother than the 'choppy' HP curve on the stock fuel map dynos. If yours does look much better than to me, it thoroughly convinces me that the stock powerloss was all in the fuel maps and that the Mazda explanation about the ECU cutting power due to load, etc was pure bull.

And you will make a lot of money selling your mod!

Originally posted by O.R.A.

The test cars the journalists used were running 100 octaine with the J-spec ECUs. The ECU will give mo powah with higher octaine.. or at least it did before they changed it. The Japanese Renesis guys freaked when they found out that Cali only has 91 octaine and told them to put in 100 for the tests.

[/B]

Back when they first reported the lowered HP for the car, they said that the performance of the car did not change. Time slips were shown with these cars running mid 14's 1/4 mile. So, all these cars they were testing for performance are running 100 octane with Japanese ECU's? How deceitful.

Originally posted by synthtk
What octane gas are you running when your doing this testing? Will you be making a map that will be safe with California Piss (91 octane)

-Chris
Shell Optimax 91 Octane.

Originally posted by mplc
Would the AT see proportional results?
This will NOT apply to the AT. We are doing our tuning on an MT GT model. To do an AT we would have to:
1) Have one to tune on.
2) Have sufficient demand to make it worth it.
We are at about 100 man-hours in this now, It all takes time.
I am lucky that a friend who has a pro tuning shop was interested enough in the project to donate his time and dyno time for this.

Replaced my coil packs tonight, and all is well. No harm done to the car.

Will be resuming early next week. I have "Stuff To Do" that has been neglected, like finishing taping my basement renovation..

Originally posted by nk_Rx8
Canzoomer,

First, great work! Second, how do your dyno plots look on the top end compared to stock? The torque curve probably doesn't drop like the stock one does, but I was wondering if it looks much smoother than the 'choppy' HP curve on the stock fuel map dynos. If yours does look much better than to me, it thoroughly convinces me that the stock powerloss was all in the fuel maps and that the Mazda explanation about the ECU cutting power due to load, etc was pure bull.

And you will make a lot of money selling your mod!

OK, the suspicions about the top end raggedness being due to the rich mixture are true.

Once leaned down it pulls properly to the top, and is much smoother. Interesting note in this is that we see that we are getting HP peak at just over 8,000, NOT 8500. At 8200 it flattens off. I suspect that with better gas we may see that keep rising a bit more. Also, bear in mind we are tuning at 735 meters altitude ( 2400 feet). That may also be taking a bit off our top end.
I think that most of the power loss is in the fuel maps.
We feel we are getting at least the original claimed power now.
Hard to say for sure, as we are not dynoing the engine. We are running the car, driveline loss and all.
I do know that with emissions legal fuel mapping, and some headroom left on it so there is no risk of detonation we pull an increase of about 30 wheel HP. We can go a bit higher, but I feel that to do so would put limitations on the fuel you can use.
We are working on the basis that what we do needs to be safe to run on at least mid grade gas (89 octane).

With the ignition there is also room for improvement. Until we smoked my coil packs we were gaining about 11HP at fairly conservative timing settings.

The next bunch of runs we have to do it to finish the ignition tuning tests, but before we do that we have to confirm our theories on what overheated the ignition coils.
We will be doing a bunch of scope testing to confirm that the ignition signals on our controller properly match the signal from the ECU before we can do much more with that. I can't afford a $400 set of coils too often!

Once that is done the next step is to dial in combinations of the fuel and ignition maps to see what balance of fuel and ignition give the best results.

We probably have about 30 to 40 hours of test time in the shop using the dyno left to do, and some good road runs before I will be satisfied.
I am hoping the weather holds out for that to go smoothly.
Up here it could turn to winter any day now. We almost always have snow on the ground by Halloween.

As for the money, I hope we can make some.
I think there are a lot of us who would like it, but of course there are certainly others doing the same thing, but not talking about it.
I have heard that Technosquare are doing tests, but their approach is to try and reprogram things on the original ECU. From what I hear they are having difficulties as the ECU seems to "correct" for mods you insert in the code. That is rumour, so may be totally false, so please don't flame me if i turn out to be wrong in this.

Fuel and ignition controllers are not a new thing, so it is not like we are inventing any new technologies!
We are also not really interested in reaching maximum theoretical power. We want to end up with a result that is reliable, and will not break cars.
I will grant that what we are doing will possibly shorten the lifespan of the cats, if they are left on.
Still, we are tuning to richness levels that are common on other cars, so I doubt the negative effects will be appreciable.
We are also temperature monitoring the cats now, so we make sure they don't get too warm.

Overall, if we can get about 10HP higher than the original 247 figures i will be quite satisfied.
I know ther are some that would prefer to reach more extreme levels, but as we are doing this on my car, and i don't want to smoke it, I am being a bit shy..

You are doing some very interesting work here canzoomer. What I don't get is why Mazda made such sloppy maps for its flagship car. At any rate, I am pleased that it was the mixture all along that was causing the power loss and not somthing more sinister like some of the more vocal bashers were saying initially.

The real question is, if you can do this, why hasn't Mazda? I realise that this renders the 8 non compliant in Cali due to the 15 minute warm up time, Mazda could have released a federal version and a Cali version, thus saving themselves a PILE of bad publicity and returns of 6% of pre-ordered RX-8s.

What I'm really interesting in seeing is what the gas mileage does. Right now the average seems to be poorer than my 12A powered 4bbl carbed RX-7 does, and that is just plain wrong.

Originally posted by SA22C
You are doing some very interesting work here canzoomer. What I don't get is why Mazda made such sloppy maps for its flagship car. At any rate, I am pleased that it was the mixture all along that was causing the power loss and not somthing more sinister like some of the more vocal bashers were saying initially.

The real question is, if you can do this, why hasn't Mazda? I realise that this renders the 8 non compliant in Cali due to the 15 minute warm up time, Mazda could have released a federal version and a Cali version, thus saving themselves a PILE of bad publicity and returns of 6% of pre-ordered RX-8s.

What I'm really interesting in seeing is what the gas mileage does. Right now the average seems to be poorer than my 12A powered 4bbl carbed RX-7 does, and that is just plain wrong.

I think Mazda can do it, and did originally, but had to reprogram in something at the last minute at port for emissions and cat durability. And when the cars were all sitting in port and costing money everyday they didn't get to the dealers, Mazda had to come up with something very fast, without much consideration to negative affects on performance. So who knows, their engineers could have just quickly used numbers that they knew would get the cars out of port quickly or maybe they even used the Euro fuel maps. Now they can't give the orginal maps back to you even if they want to. The aftermarket can do whatever they want to though since they are not the manufacturer.

Originally posted by nk_Rx8


I think Mazda can do it, and did originally, but had to reprogram in something at the last minute at port for emissions and cat durability. And when the cars were all sitting in port and costing money everyday they didn't get to the dealers, Mazda had to come up with something very fast, without much consideration to negative affects on performance. So who knows, their engineers could have just quickly used numbers that they knew would get the cars out of port quickly or maybe they even used the Euro fuel maps. Now they can't give the orginal maps back to you even if they want to. The aftermarket can do whatever they want to though since they are not the manufacturer.

That's not a valid point. There are new RX-8s being shipped to the US every day. Mazda is still manufacturing them in Hiroshima. There is ample time to test and develop new maps for the cars coming off the assembly line and to reflash the cars that have already been sold. If canzoomer can tune the 8 and still maintain 48 state emissions compliance, then there is no reason why Mazda's engineers can't give the maps a tweak themselves.

Originally posted by SA22C


That's not a valid point. There are new RX-8s being shipped to the US every day. Mazda is still manufacturing them in Hiroshima. There is ample time to test and develop new maps for the cars coming off the assembly line and to reflash the cars that have already been sold. If canzoomer can tune the 8 and still maintain 48 state emissions compliance, then there is no reason why Mazda's engineers can't give the maps a tweak themselves.

Yes, there is a reason:
It is likely (not certain, we simply do not know, and are ONLY SPECULATING!) that Mazda had to use fuel and ignition settings in the ECU that have cost power and mileage.

It is probable that they did this to meet newer emisions specs, mainly in California.

It may be difficult, if not impossible to program the ECU to meet the more strict standards, such as in California, unless you severely de-tune the car.

Nothing has changed since the summer, and it may be that nothing will. In other words the RX-8 and the Renisis might only be capable of this power and economy level if it is legal for all North American jurisdictions.

They are certainly not complete idiots, and if it was a simple thing then they would have done it this summer.

The fact that they made the announcement very shortly after releasing the first cars from port indicates (at least to me) that they became aware of this problem quite some time prior.

As we have seen with other matters, like the oil light/oil pan problem, the Canadian floor mats, and so on, it takes Mazda at least a month to respond to anything, so they must have known about the ECU / emissions issue at least as early as when the cars first hit port.

Basically they have made three grave errors:
1) they tried to hide the problem when they should have been frank to the owners and dealers about it.

2) They lied about it.
They were forced to admit there was a problem, but again, instead of disclosure, they tried to use spin to minimize it. The claim of 238HP is pure bullshit. The fact that they will not comment about the mileage is further evidence to support this.

3) They stopped listening to the engineers who designed the car, and instead listened to the lawyers. The lawyers did not design these cars. If they did they would resemble Chevy Impalas.

Mazda gave me a nice brochure about the RX-8 when i first paid my deposit . In it they claim mileage figures that state:
City: 12.8l/100km
Highway: 9.2l/100km
NOBODY on this forum has managed to get even close to those figures. And some have tried as hard as they can, because they are desparate to do so to dfend their cars against their perceptions that some of us are "attacking" them.

If they started installing a new ECU code now, all owners would want it.
Add the cost of doing that to the cost for the buybacks, $500 rebates, their legal bills, and "free" service and it adds up to a lot of money.

More importantly it would be an admission that the problem was fixable in the first place, and they would be liable again for people to sue them successfully.

They have painted themselves into a very smelly corner.

Thank the lawyers.

It is now time for us all to show some sense and act with maturity.
The information I state above, while not proven, is the most likely scenario.
If you were totally unhappy you would have taken the buyback, and would not be on these forums any longer.

Instead of dwelling on the past, the rest of us now have two choices:
Live with it.
Fix it.

The good news is that it is "fixable".

When i made my final decision on the buyback, i reached this point:
"If I sell them the car back, I will have to buy another car. Every other car I have seen with similar or better performance and amenities and features will cost at least $6,000 more (Canadian).
What can i do to improve it for less than $6,000?
Will that make it as good or better than the alternative cars?"

The answer is obvious (to me anyway): YES!!

Some of you are applauding me for working on it.

Thanks, but let's be pragmatic:
When i made the decision, based on the reason i state above, I set my self a budget of $5K. That is a saving of $1K over the next alternative car i would have bought.
I decided that I was willing to spend up to $5,000 to keep the RX-8, get at least as good, and probably better power and mileage than originally stated, and to do so in a proper professionally installed fashion.
One can do quite a tidy bit with $5K on a car.
I am paying fuel and ignition timing, suspension components, and a blower. I am spending that much on parts and labour on my RX-8. I do not count my time and labour in the total.
Because I am a capitalist pig I also hope to get some payback by selling the fruits of my labours. That will hopefully pay for my work, and maybe pay for a bit more. I thnk that after all the time and attention on this, I owe my wife something too..
If I make a couple of $K on selling performance kits for RX-8's I will spend it on something nice for her, like a weekend in Vegas, or something equally pleasing to her.. It is only fair!

And I, for one, am happy to do so. Once all is said and done I think I will own a car that eats 350Z's, Subaru WRX STi's and Mitsubishi EVOs alive.

:D :D :D :D :D :D :D :D :D

Originally posted by SA22C
That's not a valid point. There are new RX-8s being shipped to the US every day. Mazda is still manufacturing them in Hiroshima. There is ample time to test and develop new maps for the cars coming off the assembly line and to reflash the cars that have already been sold. If canzoomer can tune the 8 and still maintain 48 state emissions compliance, then there is no reason why Mazda's engineers can't give the maps a tweak themselves.

Hi SA22C,

Do not forget that the US EPA testing process is very strict and the cars MUST pass emissions tests at 50,000 and 120,000 miles. To do this, the cats must last 120,000 miles and still be in good condition.

I believe the EPA's test also measures emissions performance immediately after startup. If a modified 8 doesn't have low enough emmissions levels just after startup, it would not pass teh test that Mazda has to put the cars through.

Brian

Originally posted by canzoomer
When i made my final decision on the buyback, i reached this point:
"If I sell them the car back, I will have to buy another car. Every other car I have seen with similar or better performance and amenities and features will cost at least $6,000 more (Canadian).
What can i do to improve it for less than $6,000?
Will that make it as good or better than the alternative cars?"

The answer is obvious (to me anyway): YES!!

Some of you are applauding me for working on it.

*gives canzoomer a big warm hug*

i'm using this quote all over the place, from now on.

everyone is commending your work, i'm glad cooler heads prevailed.

If you're able to pull this off...and every indication so far is that you will...I for one hope you become filthy stinking rich off of it. I don't yet have an 8, I've been ben of a mind to stick with my FD for the time being...but the more I read this thread the more I want one!

jds

Originally posted by canzoomer


I thnk that after all the time and attention on this, I owe my wife something too..
If I make a couple of $K on selling performance kits for RX-8's I will spend it on something nice for her, like a weekend in Vegas, or something equally pleasing to her.. It is only fair!

And I, for one, am happy to do so. Once all is said and done I think I will own a car that eats 350Z's, Subaru WRX STi's and Mitsubishi EVOs alive.

:D :D :D :D :D :D :D :D :D

Originally posted by wakeech


*gives canzoomer a big warm hug*

i'm using this quote all over the place, from now on.

everyone is commending your work, i'm glad cooler heads prevailed.
Thanks keechman!

I am STILL P'ed off at Mazda. But, sometimes the best solution is to "go with the flow"..

As far as "work" goes, i admit I am having a LOT of fun doing this!

Check your 'pm's zoomer....
.
.
.
doc

CHECK YOUR 'PM'S' DOC!!!!!!!

Once all is said and done I think I will own a car that eats 350Z's, Subaru WRX STi's and Mitsubishi EVOs alive.

Now we're talkin:)

Canz - sounds like you plan on seeing a good improvement in mileage too.

I'm getting goosebumps all.

Canzoomer,
The progress that you have made so far is promising and the idea of a true plug-and-play piggy back unit is very appealing but this discussion has also got me thinking. What will happen if our cars do not match the way that yours has been setup up during all of this developement?

It sounds like your car is stock with the exception of the piggy back unit but with mine I already have a Borla cat back exhaust on order and also plan to add a cold air intake at somepoint in the future. Will the extra airflow cause the engine to run too lean with the fuel maps that you are developing? Inquiring minds want to know! :p

Originally posted by canzoomer

Hell yes!

That IS the plan. We will be selling a bolt in fuel ( and maybe ignition, we will see) controller for the RX-8.
I expect to have them available by the end of October. I am not paying for all of this just for fun!
I have to get some money back on my investment.
Do you know what 100+ hours of dyno and tuning shop time costs??

The slowest item for our builds to come in are the connectors to allow you to just plug it in to your ECU's sockets.
We have to use matching male and female connectors to match the ECU, and then we run a harness out from that to the controller, which will be in an aluminum cast box.
Install will take about 15 minutes, as will removal.

We are targetting a fuel map setup like this to sell at around $1,000 and with ignition controller around $1500.
Late, we are contemplating a unit with multiple map capability for around $2,000 for the full kit.
If we manage to get enough numbers we could easily drop it down quite a bit, but for now I am basing numbers on 10 people buying it.
All prices stated are in Canadian dollars, so if you want US cost multiply by .75 ( $750, $1,125 and $1,500).
Taxes and freight extra. Shipping weight around 20 lbs.

With the multi-map setup we would provide at least 3 maps:
1) stock
2) NA tuned fuel and ignition.
3) boosted 6 lbs

Or something like this

We will also likely do a cat-back and mid pipe solution after that.

Feedback is welcome and definitely invited!

Canzoomer,
Would you be willing to do a "trade-in" program for us early adopters? By that I mean, if we buy your fuel controller when it first comes out will we be able to send it back to you to be updated and/or reflashed when you release the fuel/ignition controller or the multi-map setup? Of course we would gladly pay the difference in price between the models.

It would be similar to the business model that Mike Valentine is using with the V1 radar locator. Hey, it may even give your products the same cult like following! :D

First Shebam gonna pm ya I live in close to baltimore and these seem like easy installs so i would help ya out np.

Second Zoomer great work sign me up the moment its done.I could have at least 2 sales for you here tommorrow.

Third anyone wanna bet who retails first bolt on supercharger?

Originally posted by Speed Racer


Canzoomer,
Would you be willing to do a "trade-in" program for us early adopters? By that I mean, if we buy your fuel controller when it first comes out will we be able to send it back to you to be updated and/or reflashed when you release the fuel/ignition controller or the multi-map setup? Of course we would gladly pay the difference in price between the models.


That makes perfect sense.

Yes, I think we would do that.
I will talk it over with my collaborator, but I can't think of any reason why not.

Canzzomer, you say you base your selling price on 10 people buying it!!?? If you get it done soon you will sell hundreds!:D

Originally posted by Sneakyracer
Canzzomer, you say you base your selling price on 10 people buying it!!?? If you get it done soon you will sell hundreds!:D

Good! Then i could afford to buy more toys for my 8!

And maybe drop the price too..

However I will not count THAT chicken until it poops on my desk..

;) ;) ;)

Originally posted by canzoomer


Good! Then i could afford to buy more toys for my 8!

And maybe drop the price too..

However I will not count THAT chicken until it poops on my desk..

;) ;) ;)

I think 10 is a viable base - you won't be the only kid on the block doing this, early to market is your best strategy.

BTW, 20lbs shipping weight ??? How much hardware are you stuffing in this thing?

Yes, 20 lbs should be about right.
Fuel controller go in an aluminum case around 6" x 9" x 2"

With optional ignition controller we would either make a larger case (probably) about 2" wider, or in a second case about 4" x 5" x 2"

Both will go under the dash, and a wiring harness will be included.
It plugs in to the ECU in place of the original harness connections, then we provide a socket for the original to plug in to.
This is under the hood. The harness splits out the fuel and ignition and a few wires ( about 15 wires) to go through the firwall to under the dash. If you look behind the bottle for washer fluid there is a cover plate on a hole through the firewall. This is where the steering passes through on the Japan ( right hand drive) model.

With the Apexi computer it is designed to be mounted on or in front of your dash:
http://www.apexi.co.jp/products/electronics/super.html

I assume one can purchase just the $750 fuel controller if that is all the mods they want?.........I would be interested, and guess by your estimates you figure this will return the car to 247hp?.........always done the chip or filter mods, so not familiar with this...........is this a big process to get it installed?...does it do anything to the warranty?.......where did you get ahold of this controller?............thanks!

Canzoomer, I am in Edmonton as well, and with the info you have posted I am impressed..........my 8 does not come until Feb04, but I like the mod options you have looked into.........I think a friend of mine had a fuel controller on his 2003 Vette, but this was purchased after market..............just curious, have you worked on these things (car mods) for a while?.........

Originally posted by Broker73
I assume one can purchase just the $750 fuel controller if that is all the mods they want?.........I would be interested, and guess by your estimates you figure this will return the car to 247hp?.........always done the chip or filter mods, so not familiar with this...........is this a big process to get it installed?...does it do anything to the warranty?.......where did you get ahold of this controller?............thanks!

Yes! I expect that this is what the majority of people will want.
It accomplishes 2/3 of the possible tuning gains, and at a reasonable price point. With fuel alone you will get at least the 247, and a bit more.

The ignition is for those who to get the most out of it, and don't mind spending more to get it.

In general one can do the fuel controller and leave the rest of the car quite stock and get very good results.

If one wanted the ignition kit too, it would make the most sense to also do the exhaust system and probably an intake.
While I have no test results to back this up yet, I believe that with fuel, ignition, exhaust system and intake, it is quite feasible to gain 50 to 60HP at the wheels.

However that means a car that is not emmissions legal, and would be quie a bit louder than stock.

Pretty well aimed at those who want to run on a track.
While I am sure there will be some who do this on the street, it is not "subtle" at that point.

As to getting it and installing it, we will be selling them in about 2 weeks, and the install is about a 30 minute job with wrenches and screwdrivers. The biggest work is routing the harness to under the dash. The work under the hood can be done in about 10 minutes.

As for my experience with this, i have owned a few cars, done a few mods, and so on. The people i am teaming with on this are in the business of performance tuning, and are a local dealer for Apexi, Greddy, Injen, Compeition Clutch, Fidenza Gears, Lightspeed Innovations, Evolution Lighting, Tein Suspension, Comp Electronics, and Nitrous Express.

The owner does mostly tuning and performance mods for their business, and have a fair bit of experience.

I mainly slelected them due to the fact that they are the local region Apexi dealer, and have had the Apexi training program. Apexi makes the best tuning items for the RX-7s, especially the Turbos.

Canzoomer, you're using out steering hole ?

Bugger!

Does having the Apexi give you the ability to play on the fly?

http://www.rx8forum.com/showthread.php?s=&threadid=12287

Kind of easy, cheap and low-tech but from what I see it should work.

Ideas?

Vince

Originally posted by compaddict
http://www.rx8forum.com/showthread.php?s=&threadid=12287

Kind of easy, cheap and low-tech but from what I see it should work.

Ideas?

Vince

Car uses secondary from about 4000 rpm and up.
Unfortunately 4000 to around 5000 it actually runs a bit lean, then starts to get richer until around 6K when it is WAY too rich, and again boosts fuel at 7200

If you diminish the secondary you will run extremely lean 4K to 5K+

Not advisable..

Originally posted by BillK
Actually the 8 really is lightweight, especially for a four door.

Now, start talking about cars like the BMW M3 that weighs around 3300 and the Audi S4 that weighs in at near 3900 lbs...

But those two cars have the engine power to move that weight around...

Originally posted by canzoomer


Car uses secondary from about 4000 rpm and up.
Unfortunately 4000 to around 5000 it actually runs a bit lean, then starts to get richer until around 6K when it is WAY too rich, and again boosts fuel at 7200

If you diminish the secondary you will run extremely lean 4K to 5K+

Not advisable..

Agreed, my wideband digital reader needs a firmware update, but I can see the trend line as the rpms climb. I did another post on a/f... Ignore that one, and I'll have track condition results this weekend!

Originally posted by canzoomer


Car uses secondary from about 4000 rpm and up.
Unfortunately 4000 to around 5000 it actually runs a bit lean, then starts to get richer until around 6K when it is WAY too rich, and again boosts fuel at 7200

If you diminish the secondary you will run extremely lean 4K to 5K+

Not advisable..

It would be nice to have the hard data on what each injector contributes and when.
From what I can see of the design and from the location of the secondary injector it looks like you wouldn't want it doing a whole lot until 5500-6000 (and kicking it up around 7000) RPM.
Basically Mazda is using three staged injection along with a three staged intake system and trying to make the transitions smooth.
I would guess that the secondary is just being tickled at mid RPM so that when it does start really contributing its effects are not as disruptive to the system.
Again, I'm guessing you have mapped (as best you can) what the sequence and contributing percentage of the three injectors are?

Curious in Auburn!

Vince

Originally posted by compaddict


It would be nice to have the hard data on what each injector contributes and when.
Indeed, it is nice to know. We have a lot of hours invested to find this out!

From what I can see of the design and from the location of the secondary injector it looks like you wouldn't want it doing a whole lot until 5500-6000 (and kicking it up around 7000) RPM.

You would think that, but the injectors have a lot more capacity than what is needed. That is not a bad thing, as it means that if people want to do more radical things later they will not have to worry about having insufficient fuel supply capacity. However what we see in general is that the stock ECU mapping delivers very little fuel in midrange.
Surprisingly too little fuel.
It is on the verge of knocking in midrange rpm, and they are retarding the timing to compensate. By slightly upping the midrange fuel delivery we were able to add almost 3 degrees of advance. This came as a big surprise to us, as we originally thought that the only significant gains were to be made at the top end.
In fact the power gains available are pretty linear from 4,000rpm and up. There is more torque potential lost in the midrange than in the top end.
To get the most from this motor you really have to provide a completely new map from 3,000 and up. I am not going to go beyond these generalities, as we have invested a lot of time, and intend to get some payback on our work!

Basically Mazda is using three staged injection along with a three staged intake system and trying to make the transitions smooth.

Actually it is quite a bit more complex than that. They have three sequential intake sections coming online in sequence, but they also have 3 separate stages where intake runner paths, volume, and length are retuned along the way.
For example at 6,000 all the paths are open, but at 7250 a crossover path opens and shortens the effective intake tract length by half.

I would guess that the secondary is just being tickled at mid RPM so that when it does start really contributing its effects are not as disruptive to the system.
Again, I'm guessing you have mapped (as best you can) what the sequence and contributing percentage of the three injectors are?

Heck yes! Along with exhaust temperatures, and now we are working on road condition ram air effects. There is significant gain to be had as the stock intake has a marked ram air effect, but it is being throttled by the exhaust.
The next step after the fuel/air and ignition is completed to our satisfaction is to re-run a lot of it with a less restrictive exhaust system. That will have significant effects on the maps. I can say that if anyone were to just bolt on a semi-wide open exhaust they will be rather disappointed with the results. The port tuning on the Renesis favour midrange power over top end. I expect to see best tuned horsepower will fall very close to best torque levels, in around the 5200-5500rpm range once fully utilized.
I also expect to see some gains to be had with dual path exhaust tuned like an expansion chamber.
The flow patterns of it are eerily similar to a 2 cylinder 2 stroke piston port motorcycle engine.

The potential of this engine is simply huge. When we started we did not expect it to respond as easily as it did.

I feel it is quite feasible to make 300HP on this engine naturally aspirated with no internal modifications. It flows very well.

Once people build up racing versions of this I expect to see a lot of surprised faces.
The biggest limiter on the potential is probably the transmission. RX-7's had a bit of a rep for having glass trannies, and I don't know how much stronger ( if any) this one is.
At 260HP it should not be an issue, but at 300+ ? scary.

Curious in Auburn!

Vince

Having a lot of fun in Edmonton!

One thing people should watch out for if they do any serious work on the RX-8 is to keep an eye on the exhaust.

After doing some hard runs with improved fuel/air, and ignition, we noticed a funny smell coming from the rear.

Let's just say that the accessory that you can buy that is a metal insert around the exhaust tips is potentially more than an ornament.

Take a look at this picture:

Originally posted by canzoomer
One thing people should watch out for if they do any serious work on the RX-8 is to keep an eye on the exhaust.

After doing some hard runs with improved fuel/air, and ignition, we noticed a funny smell coming from the rear.

Let's just say that the accessory that you can buy that is a metal insert around the exhaust tips is potentially more than an ornament.

Take a look at this picture:

Alright, just a quick dumb quote...those have to be some darn hot exhaust gasses coming out.

I understand the need to keep the information you are doing the work for to yourself.

Thanks for sharing what you can!

Vince

Originally posted by RX8-TX


Alright, just a quick dumb quote...those have to be some darn hot exhaust gasses coming out.

Yes.

When we did this we had the cats removed and just the muffler on the exhaust.

The setup was fuel/air tuned and it had some advance on ignition.

The gases coming out were VERY hot. I would bet that with a racing exhaust and a tuned engine you would see flames coming out at least at night!

The plastic is too close to the tailpipes.

The part one would need to install if leaving the stock plastic in place and running a full race ehaust is this one:

Originally posted by canzoomer


Yes.

When we did this we had the cats removed and just the muffler on the exhaust.

The setup was fuel/air tuned and it had some advance on ignition.

The gases coming out were VERY hot. I would bet that with a racing exhaust and a tuned engine you would see flames coming out at least at night!

The plastic is too close to the tailpipes.

The part one would need to install if leaving the stock plastic in place and running a full race ehaust is this one:

That does it!!!

A big fat single flame throwing centre exhaust it the go ... just imagine toasting the pedestrian that walks behind your car ... literally :(

I'm confused about the lean midrange part of the maps. Doesn't this run counter to the concept of running it rich in order to save the cats? Or is all of that bogus too? :-(

jds

The situation with the heat would only occur on a car with essentially wide open exhaust and extensive installed performance mods.
In other words not what you would run on the street ( at least I hope not!)

Watch some GT or F1 races on TV or at a track and you see the same thing. Some of the endurance races, such as 24 hours of LeMans are a great example. Flaming exhausts, glowing brakes, sparks from undercarriages.. Cool stuff.

As far as the question about lean/rich situation and the cats, they run lean where the engine is at lower rpm, and flowing less volume of gases, as the cats are not getting as much heat from the exhaust ports at lower rpm.

When you open the throttle and increase rpm the total gas flow goes up fast, and they had to add more fuel to cool it down. This has resulted in bad gas mileage at higher rpm, loss of power, and that black smooty stuff we see on our tailpipe tips.

In essence the tuning is being done with a goal of keeping catalytic converters at their ideal temperature for maximum emmissions performance at all rpm ranges.

They are NOT being tuned for producing better gas mileage or horsepower.

While I am neither a tree hugger or an SUV driving gas pig, the emissions tuning they are designing for is for the most strict jurisdictions, such as California, and not for places with less strict regulations.

The work we are doing and soon will be offering to other owners is designed to operate within the specs for the majority of North American jurisdictions, and would not be legal in all places.

We are also tuning to work with mid grade or high grade fuel. In other words 89 octane or higher.

Mazda has tuned ignition timing and mixture to be safe and knock free even on 87 octane gasoline.

Different design goals produce different results.

Originally posted by canzoomer
The situation with the heat would only occur on a car with essentially wide open exhaust and extensive installed performance mods.

....

Mazda has tuned ignition timing and mixture to be safe and knock free even on 87 octane gasoline.

Different design goals produce different results.


Best post yet! Right on the money.

I've been meaning to post something about the economy/power/emissions issue for the last few days but haven't had the time to do so.

Mazda's goal for the RX-8 was for it to have much better mileage than what it currently has and they meant for the motor to run lean. They have spent years developing the catalyst technology to work with a lean running side port rotary.

SAE article 950454 : "The Characteristics of Fuel Consumption and Exhaust Emissions of the Side Exhaust Port Rotary Engine" has a wealth of information regarding the economy, emissions and power performance of a side-port rotary. You can find it on the web although people that buy it aren't supposed to put it up for public consumption.

Be very clear that emissions regulations are what has drastically lowered the power of the RX-8 (from the original 280 of hte RX-Evolv). The main problem is that the new regulations for new and upcoming cars require that they be able to pass strict tests at 50,000 and 120,000 miles.

Mazda has made great strides in catalyst technology in the last 10 years. They developed the "world's 1st 3-way catalyst for lean-burn engines" and in 1998 developed another 3-way catalyst that "starts to purify pollutants from a 70 degree (C) lower temperature than current catalysts" and has a heat resistance "100 degrees (C) higher than current catalysts".

The side-port rotary actually produces more power at the leaner ratios. (See attached graph) Mazda has also released info (a year or 2 ago) that states that "the RX-8 operates with a lean mixture even during high-speed high-load operation."

http://www.rx8club.com/attachment.php?s=&postid=137282

Despite the the capabilities of the Renesis and the advancements Mazda has made in catalyst technology, we are not seeing the full potential in power or fuel economy of the RX-8 because of catalyst longevity.

For those people that do not believe that the renesis is running rich to preserve the catalytic converter, please also note the below which was released several years ago by Mazda regarding catalyst longevity:

"Current three-way catalysts are located as near as possible to the engine in order to make the temperature of catalysts rise sooner. But, under engine conditions such as high-speed driving, deterioration of the catalyst accelerates due to the high temperature of exhaust emissions from the engine. Usually, the temperature of emissions are lowered by injecting additional amounts of fuel into the engine's combustion chamber."

The potential in fuel economy and power IS there. The RX-8 has the potential for great power increases and fuel economy improvements with the lean mixtures it was designed for. As mentioned before BWOB has written about how difficult the EPA testing process is. Hopefully, Mazda's engineers can take the RX-8 to the next level if they can overcome the catalytic converter longevity problem.

Brian

Canzoomer:

Am I right about about how the secondary injector contributes?

Curious in Auburn...

Vince

So assuming you can lean out the mixture to produce more power then you're running the risk of destroying the cats prematurely and not being able to pass emissions? Anyone care to venture a guess on when that might happen? :) How much are replacement cats?

If I read correctly...
The cats were moved up close to get them up to temp quicky for Cali emmisions test. This results in higher Cat temps at higher RPMs.

So, Why couldn't someone not concerned with the quick warmup issue, move the cats back. This could allow us to run less rich at higher RPMs while still keeping the cats cooler.

Is this not an option?

Originally posted by Reeko
Why couldn't someone not concerned with the quick warmup issue, move the cats back. This could allow us to run less rich at higher RPMs while still keeping the cats cooler.

Is this not an option?

well, you "couldn't" because it's illegal to change the distance of the cat to the engine (thanks DOT!!)

anyways, if you really want to save your cats, you could always replace them with a straight pipe for competition, then put 'em back on later for normal driving... or whatever, leave 'em off other than for tests... *shrug*

best way to save cats is not to use them...? ;)

Except that running without cats would probably throw a few CEL codes.. and if you ever get caught, in the Toronto area anyway, they pretty much give it to you up the pipe, so to speak. :) Big crackdown around here on those kind of mods.. $5000 fine I think for tampering with emissions systems?:confused:

Also if you've ever seen a city under a smog alert that alone should convince you to not run without cats.. I wouldn't do that just to gain 20 hp.

Originally posted by Reeko
If I read correctly...
The cats were moved up close to get them up to temp quicky for Cali emmisions test. This results in higher Cat temps at higher RPMs.

So, Why couldn't someone not concerned with the quick warmup issue, move the cats back. This could allow us to run less rich at higher RPMs while still keeping the cats cooler.

Is this not an option?

The cats are moved up close because of EPA testing that measures emissions just after startup. I believe this is a national issue not a California issue. Manufacturers have to be concerned with the quick heating of the catalytic converter because the EPA says they do.

Like it or not, emissions regs are getting tougher every year (in the US and worldwide).

Unfortunately many engineering goals are contradictory in nature. The cats need to be hot at startup so that they can start working... but they can't be too hot at high revs or they will deteriorate faster. You can see that the close cat placement and the double-skinned exhaust manifold before the cat help startup emissions but end up hurting high end power if cat longevity is a goal.

Brian

First let me say emmisions is a joke.Ever been behind a 20 year old dumptruck as they drop 20lbs of carbon in the air before they even move.Second how the hell do you ever get caught running without a cat?Personally i cant see your average traffic cop getting on the asphault to look even if he knew what he was looking for in the first place.

Originally posted by WTF no turbo
First let me say emmisions is a joke.Ever been behind a 20 year old dumptruck as they drop 20lbs of carbon in the air before they even move.Second how the hell do you ever get caught running without a cat?Personally i cant see your average traffic cop getting on the asphault to look even if he knew what he was looking for in the first place.

They do look in Cali, then it's a call to the REF to get your car inspected.

A lot of times, it's just inspections for "rice" looking cars, or people they can actualyl pull over at the illegal races.

Originally posted by WTF no turbo
Second how the hell do you ever get caught running without a cat?Personally i cant see your average traffic cop getting on the asphault to look even if he knew what he was looking for in the first place.

you go to get your emissions testing done and you don't pass. they see that you don't have a cat. and i have seen cops lay down and look under a car to see if the cats and/or mufflers have been removed.

You are absolutely right.

It realy depends on who you are and what you look like and where you are.

I am 47, white, and live in Alberta. My chances of an inspection are slim to none.

If I was Asian, 21 , and lived in California i would drive ONLY stock, and probably a K car!

Sorry officer, I guess i was not paying attention to the change is speed sign back there.
Thanks for the warning. I will not do it again.

BTW Officer Pete, are you and your wife coming out to the golf club this Saturday?

Canzoomer, thanks for the chat the other night.....love to see the car when you get the fuel controller hooked up.........I will be buying one when I get my 8........another 20-25hp only adds to an already great car!......went out today in a G-35 coupe with a friends who picked it up today.......nice car, but made me more thankful I got the 8.....probably just as fast stock, but with 25hp more, there is no comparison.....just my opinion.......

Just don't get a blue one!

I am getting used to the exclusivity around here..

don't worry, my 8 will be black!..........I'll touch base with you in a week or so, and maybe we can go for a spin........you have me curious how much more zip the mods give it !

your car looks great!

nice pic canzoomer

Originally posted by Buger
....Be very clear that emissions regulations are what has drastically lowered the power of the RX-8 (from the original 280 of hte RX-Evolv). The main problem is that the new regulations for new and upcoming cars require that they be able to pass strict tests at 50,000 and 120,000 miles.

.....Despite the the capabilities of the Renesis and the advancements Mazda has made in catalyst technology, we are not seeing the full potential in power or fuel economy of the RX-8 because of catalyst longevity.
Brian,

thanks for a really excellent post. At last we seem to be getting to the bottom of this mystery.

However, as a non-North America resident I am interested in whether this has the same implications in the rest of the world. As I understand it, the Euro 4 regulations for the European cars only apply for the first 100,000 km (63,000 miles) and for Australia it is 80,000 km (50,000 miles).

Do you think this would allow Mazda to run with leaner fuel maps in these markets? Or are you saying that lean mixtures at high revs will kill the cats very quickly.

Chris

Originally posted by ChrisW
are you saying that lean mixtures at high revs will kill the cats very quickly.

Chris

"quickly" means "sooner than 10 years of anticipated levels of use". it's not as if the cats will melt down instantly, but that longevity will be effected in an unacceptably large margin over a long period of time.

Does it have to be the same cat in the Euro stage 4 emisions at 100k?

Say I , being a nonce, put a huge screwdriver through the cat whilst changing/repairing something, and had to buy a new one. What then?

Pbviously the cat sucks power, but is it restricting flow a lot? Would a 3rd party sports cat (available for elise,focus etc here) be better and/or legal?

Originally posted by canzoomer
Sorry officer, I guess i was not paying attention to the change is speed sign back there.
Thanks for the warning. I will not do it again.

BTW Officer Pete, are you and your wife coming out to the golf club this Saturday?

Now here I was imagining that you had a carefully rotor shaped pony tail that slotted onto your seat back... :D

I haven't seen blue in the flesh, does it have the mica finish of the red?

Originally posted by Kev
I haven't seen blue in the flesh, does it have the mica finish of the red?

The blue i sjust metalic. But very nice in the metal.

winning blue is sweet
its got silver flakes
while the red has gold flakes

Originally posted by ChrisW
Do you think this would allow Mazda to run with leaner fuel maps in these markets? Or are you saying that lean mixtures at high revs will kill the cats very quickly.

Chris
Mazda UK is claiming 177KW on the web page last time I looked.
That is about the same as the 238HP claimed here..

Originally posted by canzoomer
Mazda UK is claiming 177KW on the web page last time I looked.
That is about the same as the 238HP claimed here..

Nope, nother mistake by mazda I'm afraid.

The power was 241ps, or 177kw(238bhp) but it was lowered to 231ps. Mazda just 'forgot' to change the kW value.

CANZOOMER

Keep up the good work , maybe i will do a barter deal with your upgrades on the rx8 ,we have great variety of fish and reptiles here in australia , to add to your collection , let me know of any that you are interested in .

Are you going to sell your upgrades here in australia???

Canzoomer,
I am trying to understand how the fuel remapping works (without you disclosing anything that you figured out that gives you a market edge)...

Do you remap the A/F onlt at WOT (Open-Loop?). Do you leave the stock maps for less than WOT (Closed Loop?)
Or do you have different maps?

I am trying to understand how throttle position plays into the fuel controller, and how you map it. I assume in open loop, it is just a simple look-up based on RPM (and maybe air flow). But in partial throttle, the varialbe become much more complicated, correct?

Just trying to understand how your mods would affect partial throttle, as I rarely have it WOT, I still want improved performance at partial throttle.

Rick

Canzoomer -
This may be way off, but while reading this thread I got to wondering -
It seems the ECU is keeping things rich to keep the cats cool;
Is this dependent on some sensor input? Is there something like a CAT temp sensor?

If so I was thinking that a sensor fault or sloppy tolerances could be a source of the poor MPG performance that some (like me) are experiencing. Perhaps variations in sensor performance could account for the way the cars seem to cluster into "low MPG" and "high MPG" groups.

Just some food for thought...

Dave

It is dependant on and has sensors for:
Engine rpm
Throttle opening
Air flow as seen at the mass air sensor
Oxygen levels at the O2 sensors
Barometric pressure sensor

The ECU takes these readings and based on a "map" of levels to use depending on these conditions, how much fuel to tell the injectors to squirt.
It also tells the ignition modules to fire, and varies the timing (advance) of this.

Differences that you see are probably caused by:
1) Driving habits ( biggest factor)
2) Fuel used
3) Altitude
4) Temperature
5) Barometric pressure.

Originally posted by Lock & Load
CANZOOMER

Keep up the good work , maybe i will do a barter deal with your upgrades on the rx8 ,we have great variety of fish and reptiles here in australia , to add to your collection , let me know of any that you are interested in .

Are you going to sell your upgrades here in australia???

Don't tempt me!
I keep tropical fish..

I will sell the kits to anywhere people want them. We have accounts with Fedex and DHL.

Originally posted by Reeko
Canzoomer,
I am trying to understand how the fuel remapping works (without you disclosing anything that you figured out that gives you a market edge)...

Do you remap the A/F onlt at WOT (Open-Loop?). Do you leave the stock maps for less than WOT (Closed Loop?)
Or do you have different maps?

I am trying to understand how throttle position plays into the fuel controller, and how you map it. I assume in open loop, it is just a simple look-up based on RPM (and maybe air flow). But in partial throttle, the varialbe become much more complicated, correct?

Just trying to understand how your mods would affect partial throttle, as I rarely have it WOT, I still want improved performance at partial throttle.

Rick
It varies a bit, but we are mainly adjusting from rpm levels, not throttle opening.

One of the goals is improved fuel economy. As people do not usually drive around at WOT all the time we have to account for this.
Like I mentioned before it takes many hours to take readings at all the different conditions to build the new maps. We are getting close to being done. Probably by the end of next weekend we will be happy with it, and ready to build and ship.

Build time mainly involves the making of wiring harnesses.
As we are making a harness that just plugs on to the existing harness to the ECU and to the ECU itself, it is a bit of work.

The connector on the ECU has 122 pins, about half gold and half tin contacts ( gold for data lines)

There are 5 plugs to hold all the contacts. that mate to it on the harness.

Biggest problem is that the cable plugs are easy enough to do. Just crimped connector terminals, but the mating male connector on the ECU is designed to fit in a circuit board, and is one bg connector. So, we have to modify this added male connector to receive all the plugs.
Lots of terminal crimping and soldering/wiring work to make the harness.
Programming the fuel controller, and installing it in the case is not too much work.

Once we get the volume up on the assemblies we can get a printed circuit board with connectors made to accept the plugs and that will cut the work by about half.

canzoomer, we spoke a few weeks ago, and I assume you will still be supplying this mod in Feb-Mar of 2004?.......wish I didn't have to wait that long for my car, but oh well....:(

with this fuel control system, you mentioned about 20-25hp?...

We will suppl yit as long as people want it.

As for the power, we are now debating what we should target.
We can easily get 20HP and still have cool ouput and a catalytic converter environment.
Some people wnat that as they will keep everything else essentially stock.

We can also get quite a bit more, perhaps as much as 32-35 but with higher exhaust temperatures, and more risk of damaging the first cat. Some people would rather have that, and take off their cats and stock exhaust and go for more power.

Maybe I should do a poll thread?

Originally posted by canzoomer
We will suppl yit as long as people want it.

As for the power, we are now debating what we should target.
We can easily get 20HP and still have cool ouput and a catalytic converter environment.
Some people wnat that as they will keep everything else essentially stock.

We can also get quite a bit more, perhaps as much as 32-35 but with higher exhaust temperatures, and more risk of damaging the first cat. Some people would rather have that, and take off their cats and stock exhaust and go for more power.

Maybe I should do a poll thread?

A poll thread? I think you should start a website :D

How about loading the maps from a USB key on start up (if connected) ... you could sell maps and tuned upgrades/fixes over the internet that people could download (serialized versions to map a serial number stored in the firmware to protect your investment).

Imagine an owner being able to build their own virtual map, based on the sampling you've done, then generate a custom map they could download to a USB key and test in their car.

Don't get your USB keys mixed up people - don't think the 8 will run too well with a fuel map of Prince singing Purple Rain!

I've been intently reading along with this thread for a while. You've done some outstanding work so far, Canzoomer.

1. Would there be any way for you to package multiple maps in a single, switchable controller?

2. BTW, have you produced any preliminary dyno slips? If so, could you post one or two? Images would go a long way in solidifying your initial customer base.

Originally posted by SpacerX
I've been intently reading along with this thread for a while. You've done some outstanding work so far, Canzoomer.

1. Would there be any way for you to package multiple maps in a single, switchable controller?

2. BTW, have you produced any preliminary dyno slips? If so, could you post one or two? Images would go a long way in solidifying your initial customer base.
Multiple maps: Yes. But it is more expensive. Later on we intend to use the Apexi SuperAFC2 for that.
See:
http://www.apexi.co.jp/products/electronics/super.html


Initially, however we are shooting for a low cost unit that holds one map. We will probably offer that in two versions: 20-25HP, gentle on the exhaust and 30+HP, for modified exhaust systems.

We will also offer an ignition control module to go with this tuning level, which will add another 10-12HP. This absolutely requires a complete exhaust system from the manifold back, as it makes a lot of heat, and would destroy stock cats and muffler. Furhter the exhaust, when mated with this combination, will open up flow, allowing perhaps another 5-10HP to be produced.
This will definitely be a "track kit" as there is no way in hell it would meet emmissions testing requirements.

While the FC unit can be re-tuned, this will require the unit to be sent back to us for reprogramming.

I will be putting a web page up soon, and will place dyno charts on this to illustrate results.

We will use charts from the Mustang dyno we are using, and are planning to also get som runs done on a Dynojet, as these are more common.

Please bear in mind that this is an after hours project, so we are going as fast as we can, and still have jobs, lives, families, and need to sleep once in a while as well..

My strongest motivation to complete this is the fact that my RX-8 is a daily driver, and i get reminded every day about the need.

Thanks!
:D

Please bear in mind that this is an after hours project, so we are going as fast as we can, and still have jobs, lives, families, and need to sleep once in a while as well..

Many of us have waited months just to get our RX-8. I think we can wait a few weeks to see the results of your efforts canzoomer.

Originally posted by canzoomer
The connector on the ECU has 122 pins, about half gold and half tin contacts ( gold for data lines)


Very nice job Carzoomer! I don't yet own an RX-8 but will most likely be purchasing one early/mid next year so this mod has me licking my lips.

Quick question about your statement above (and it may be a stupid and obvious question). Are you planning on using gold contacts with gold contacts and tin with tin to prevent corrosion from different metals making contact? The reason I ask is that even vehicle manufacturers make this mistake and have premature contact failure. The Nissan Xterra (which I own) and Frontier are notorious for having their fuel sending units fail prematurely because of this problem, rendering the truck useless. I'd imagine the same thing would happen with the RX-8 if the contacts leading to the ECU also start to corrode after 20-60K.

Keep up the good work!

Originally posted by medcina
Very nice job Carzoomer! I don't yet own an RX-8 but will most likely be purchasing one early/mid next year so this mod has me licking my lips.

Quick question about your statement above (and it may be a stupid and obvious question). Are you planning on using gold contacts with gold contacts and tin with tin to prevent corrosion from different metals making contact? The reason I ask is that even vehicle manufacturers make this mistake and have premature contact failure. The Nissan Xterra (which I own) and Frontier are notorious for having their fuel sending units fail prematurely because of this problem, rendering the truck useless. I'd imagine the same thing would happen with the RX-8 if the contacts leading to the ECU also start to corrode after 20-60K.

Keep up the good work!
Yes, that was the point I was trying to make ( badly apparently!)

About half the contacts on the ECU board connector are gold, and half are tin. One needs to make sure one has matched these parts with similar metals on the plug contacts that mate with them..

However, in a situation like you descrive with your Nissan, there are compounds that one can apply to the terminals that make hep them make a better contact and seal them from moisture and dirt.

Originally posted by canzoomer
Don't tempt me!
I keep tropical fish..

I will sell the kits to anywhere people want them. We have accounts with Fedex and DHL.

Can zoomer

After all your hard work you will definetely need a holiday from your work , so come to australia , and chill out , you could bring your upgrades with you and supplement the cost of your holidays by selling them here in australia , you are very welcome we have great beer , weather , women , and one of the best deepsea diving spots in the world .
michael

Originally posted by Lock & Load
Can zoomer

After all your hard work you will definetely need a holiday from your work , so come to australia , and chill out , you could bring your upgrades with you and supplement the cost of your holidays by selling them here in australia , you are very welcome we have great beer , weather , women , and one of the best deepsea diving spots in the world .
michael

Ah! I knew I was missing something!

I was in Singapore and Malaysia in July, and kept feeling this beer front blowing in from the south..

Canzoomer

In your quest to dissect the intricaties of the rx8 can you tell us how to increase the volume on the red line limiter as most of us can barely hear that beloved BEEPER as we try to find the rx8 nirvana .
Was told by mazda australia that the loudness of the BEEPER can not be adjusted , is that correct ??

Bye the way after a few good aussie beers i cannot feel the souhtherly winds only the call of the lovely sirens awaiting my sometimes uninvited advances which have had i must say a far better chance of success since my rx8 arrived , the girls all want to go for a spin , my scoring rate has vastly improved , as i am hoping will the performance of my car.

Allthe best .

michael

Originally posted by canzoomer
One of the goals is improved fuel economy. As people do not usually drive around at WOT all the time we have to account for this.

Canzommer,

You mention fuel economy. What are your projections for this? I like the idea of more power but I am more interested and getting better mileage out of my car. Power is great but the daily drive is killing me.

Mr. Load has a good point, 'Zoomer... if you could point me in the direction of that bloody beeper, I will do a replacement/upgrade post.

It is pretty well useless 'as is'.

Thanks,
.
.
.
doc

Originally posted by Doctorr
Mr. Load has a good point, 'Zoomer... if you could point me in the direction of that bloody beeper, I will do a replacement/upgrade post.

It is pretty well useless 'as is'.

Thanks,
.
.
.
doc

You make a good point. One can't hear it of the stereo is on.
So, I looked. It is a peizo electric buzzer.
5 volt apparently.
I have louder ones here if you want to have a go.

I have the shop manual, wiring manual, a decent set of tools and a big concrete driveway.

Maybe stop by tomoorw if you are not doing anything exceptional tomoorw and we can play with wiring. i wanted to do my fog lights mod anyway..

Call me if interested.. 456-1510

Originally posted by jtdwab
Canzommer,

You mention fuel economy. What are your projections for this? I like the idea of more power but I am more interested and getting better mileage out of my car. Power is great but the daily drive is killing me.

That is a big part of our goals.
I will be doing a final fit on my 8 next weekend, so after that I can use a couple of tanks and tell you the results. I have detailed records of my gas consumption up to this point, so we can certainly tell..

Originally posted by canzoomer
You make a good point. One can't hear it of the stereo is on.
So, I looked. It is a peizo electric buzzer.
5 volt apparently.
I have louder ones here if you want to have a go.

I have the shop manual, wiring manual, a decent set of tools and a big concrete driveway.

Maybe stop by tomoorw if you are not doing anything exceptional tomoorw and we can play with wiring. i wanted to do my fog lights mod anyway..

Call me if interested.. 456-1510
Does this require removing the dash, as in the RX-7s? Where exactly is the buzzer mounted? Thanks. Really excited about your work, once again.

Originally posted by B-Nez
Does this require removing the dash, as in the RX-7s? Where exactly is the buzzer mounted? Thanks. Really excited about your work, once again.

Yeah, it is in the dash, behind the instrument cluster.
About a half hour to get to it.

doesnt sound like a fun job

Are they ever? :D

Seriously though, who cares??

Isn't the darned tach BIG ENOUGH for some people??

Last thing I want to hear is yet another bloody beeper!

Yes mother, my seat belt is on.
Yes mother, my door is locked
Yes mother, my car is over-revving
No mother, I will not speed
Yes mother, my fly is done up..

Yea, yea.

What about the role of the secondary injector?

Vince

Interesting conversation today.
Through a friend in USA who is a very well known and recognised specialist contractor for (insert some performance component type here) and a conference call, I got to talk with a fairly high placed engineer at Mazda USA.

I am NOT going to say more about that part as people would be quite unhappy if I did..

Seems Mazda are considering the idea of making an ECU upgrade available to those who whine enough..
Not a cheap thing, though.

Here is the kicker:
He said it would allow those who are really dissatisfied to get 238HP..

I worked VERY hard to keep straight face and not sound amused.

We figured out a neat trick today:

Disconnect output from front wheel sensors to ECU.

Take output signal from rear wheel sensors to ECU.
Split out and hook to input on ECU for front wheel sensors.

Now ECU gets readings that tell it front and rear wheels are all turning at the same speed.

It seems very happy with that, and does not want to do anything odd.

And it makes the same power output as we got before.

Also, we did some road running with fuel control device, O2 sensor monitored, fuel/air ratios monitored, exhaust temps monitored.

Readings on road identical to those on dyno, other than exhaust temps a bit higher. Not surprising as on dyno we are not getting as much air cooling as on road, outside, at 11C ( 52F)

Note to Bern:

2nd and 3rd BS flags thrown..

I dont understand your trick of the day

On Rotary News Bern quoted somebody (un-named) from Mazda who claimed that when people put an RX-8 on a dyno the power figures would be wrong because:
"the ECU could tell that it was not running on the road" and that the ECU would lower the power output.

See:
http://rotarynews.com/view.php?id=212

"Only the rear wheels are turning while the front tires remain stationary.

On cars equipped with DSC with traction control, the difference in speed between the front and rear wheels is sensed and the power is reduced immediately to compensate for what the car senses as excess wheel spin.

If the DSC is turned off, the traction control is disabled but the brake functions of the DSC are still operational.

If the DSC system is completely disabled, this removes the brake functions from the equation, however it does not fully remove the engine management system functions.

The ABS hydraulic unit/control module (HU/CM), or the DSC HU/CM for cars with DSC, determines vehicle speed by comparing the speed of all four wheels. If two are turning and two are stationary, it will still compute a speed but senses that the car is experiencing excessive wheel spin. To protect against engine or catalyst damage:"


What the RX-8 has that could feed info to the ECU about wheel speed is a sensor on each wheel that sends pulses to the ECU and from these pulses the ECU tells how fast the wheel is moving.

There is one sensor on each wheel.

On a dyno the front wheels are not turning, only the back wheels.

So, we disconnected the front wheel sensors, fed the signal from the rear wheel sensors in to the ECU on the circuit that the front wheels normally send on.

Now the ECU is getting a reading from the front wheels that is identical in speed ot the signal from the back wheels.

It "thinks" the front wheels are turning at the same speed.

The result showed no differences.

In other words the claim that Bern / Mazda made was BS.

Clear?

Originally posted by canzoomer
Interesting conversation today.
Through a friend in USA who is a very well known and recognised specialist contractor for (insert some performance component type here) and a conference call, I got to talk with a fairly high placed engineer at Mazda USA.

I am NOT going to say more about that part as people would be quite unhappy if I did..

Seems Mazda are considering the idea of making an ECU upgrade available to those who whine enough..
Not a cheap thing, though.

Here is the kicker:
He said it would allow those who are really dissatisfied to get 238HP..

I worked VERY hard to keep straight face and not sound amused.

Hi Canzoomer,

A PCM software upgrade from Mazda would have to pass the EPA and CARB tests which caused the power loss in the first place. If it is like the Mazdaspeed Protege PCM reflash that happened last month, it should not cost anything.

It will be interesting to see how long it takes Mazda to get the new maps to pass the SFTP tests.

Brian

thanks canzoomer

Quite right. It would be sweet if they could pull that off..

I have doubts as they have had a while to work on this already, and not much news, but let's cross fingers, toes, eyes, arms, and whatever else necessary!

Why would they offer new maps AND make us pay for it? It really pisses me off when I have to clean the tips off my car every week not to mention my fuel milage. It should be free or very cheap.

D

I thought at one point someone tested the sensors and they were unpowered with DSC off and no braking? Did that turn out not to be true?

The one other thing that still makes me somewhat uncomfortable is the report from Paul Yaw a while back which seemed to validate the claim that the ECU was getting squirrelly on the dyno. Why would he think that?

jds

Originally posted by canzoomer
We figured out a neat trick today:

Disconnect output from front wheel sensors to ECU.

Take output signal from rear wheel sensors to ECU.
Split out and hook to input on ECU for front wheel sensors.

Now ECU gets readings that tell it front and rear wheels are all turning at the same speed.

It seems very happy with that, and does not want to do anything odd.

And it makes the same power output as we got before.

Also, we did some road running with fuel control device, O2 sensor monitored, fuel/air ratios monitored, exhaust temps monitored.

Readings on road identical to those on dyno, other than exhaust temps a bit higher. Not surprising as on dyno we are not getting as much air cooling as on road, outside, at 11C ( 52F)

Note to Bern:

2nd and 3rd BS flags thrown..

Originally posted by bureau13
I thought at one point someone tested the sensors and they were unpowered with DSC off and no braking? Did that turn out not to be true?

The one other thing that still makes me somewhat uncomfortable is the report from Paul Yaw a while back which seemed to validate the claim that the ECU was getting squirrelly on the dyno. Why would he think that?

jds
It is still true. I posted this.
I am not the only one who tested this.

But I also want to double check things where I can.
So, turn of DSC as with it on wheel slippage will trigger DSC and that will lose us power. Same as before, always been that way.
ABS is still on, and I want to be absolutely sure that no "magic pixie action" is happening due to that circuit.

It is quite hard to run on a dyno with the front wheels turning at the same speed. Dynos are not made that way.

So, if we can't run the front wheels at the same speed as the back, what can we do?

Simple, make the ECU THINK they are!

And the results were unchanged.

I now have two different sets of test conditions validating this.

As for Paul Yaw, Rotary News, and so on.
Ask yourself this:
"Where does the money come from?"

The answer is:
"From working on Mazdas"

Did you ever hear the story of "The Emperors new clothes"?

If we want a reflash to be offered for free rather than at a price, sounds like the thing to do is for all to complain to Mazda documenting (through records that we should start keeping in writing re date, pump and odometer reading) our MPG experience, accompanied by a personal declaration that driving style and shift points seemed to matter little (plus observations re black exhaust tips). The debit card plus free service was premised on our disappointment in the HP and said NOTHING about expecting that the cars would uniformly not come close to the EPA numbers -- or to the mileage actually experienced by Car & Driver (which I recall as 20 MPG for their mileage course, and they do not baby a car).

If our position were premised solely on HP, they could answer that they have already compensated us with about $1,000 worth of value, so it is only fair that we pay back up to that amount for the reflash, which would, in lawyer terms, "make us whole." (We would be no worse or better off than if the cars had met the original HP promise.) However, if we complain about the universal MPG experience as well, they would have some difficulty in arguing that their fix also restores our MPG back to EPA specs -- it would be dangerous for them to admit that it fell below the EPA numbers since they never mentioned this to us or compensated us for it. (They could still claim a less specific "improvement" but my guess, as a lawyer, is that this is a subject they really hope not to touch in writing.)

Since I bring nothing to the party technically, hope this lawyerly contribution is helpful.

shebam, that's what the Mazdaspeed Protege people did. They just kept contacting people at Mazda. Kept trying and pushing higher. Got some mazda people that had the car and were experiencing the same thing involved. It took a while, but Mazda did come through with a free ECU reflash for them.

Ahh, I understand now...you haven't seen anything to change the previous statements about the sensors, you've just provided more data that the ECU isn't doing anything in that case even if the sensors do somehow provide data. Got it.

I can kind of understand Rotary News being in a precarious position with respect to getting access to Mazda info, but I wasn't under the impression that Paul Yaw's operation fell into that same category. Besides, if I'm not mistaken, his observations predated Mazda's announcement...possibly even triggered it. I'm all for conspiracy theories, but I'm not sure I'm buying that one. Maybe he saw something that he interpreted as problems with dyno-ing and it gave Mazda an idea! Who knows...

The Emperor's New Engine? :-)

jds

Originally posted by canzoomer
It is still true. I posted this.
I am not the only one who tested this.

But I also want to double check things where I can.
So, turn of DSC as with it on wheel slippage will trigger DSC and that will lose us power. Same as before, always been that way.
ABS is still on, and I want to be absolutely sure that no "magic pixie action" is happening due to that circuit.

It is quite hard to run on a dyno with the front wheels turning at the same speed. Dynos are not made that way.

So, if we can't run the front wheels at the same speed as the back, what can we do?

Simple, make the ECU THINK they are!

And the results were unchanged.

I now have two different sets of test conditions validating this.

As for Paul Yaw, Rotary News, and so on.
Ask yourself this:
"Where does the money come from?"

The answer is:
"From working on Mazdas"

Did you ever hear the story of "The Emperors new clothes"?

Originally posted by canzoomer
Here is the kicker:
He said it would allow those who are really dissatisfied to get 238HP..

So does that mean he is admitting that the car currently really doesn't make 238hp like the official Mazda claim?

Bingo!

This is COMPLETELY off the record, of course.

Thing is, if you live in the USA, it might be a good time to renew your efforts with the dealer and Mazda.

Apaprently the ECU reflash is not going to be announced in a TSB or anything public. It is apparently going to be used to soothe those who are still complaining..

If you want to get greased, you have to be a "squeaky wheel" apparently.

Originally posted by canzoomer
Bingo!

This is COMPLETELY off the record, of course.

Thing is, if you live in the USA, it might be a good time to renew your efforts with the dealer and Mazda.

Apaprently the ECU reflash is not going to be announced in a TSB or anything public. It is apparently going to be used to soothe those who are still complaining..

If you want to get greased, you have to be a "squeaky wheel" apparently.

In Canada, is this re-flash going to be offered too? (also off the record)