brillo

Have you called dynojet and asked them to email you a older copy of their viewer? I'm sure they have it.

http://www.dynojet.com/about_us/contact.php

800-992-4993 / Toll Free

PoLaK

iTrader: (1)

I have and they don't, not atleast anyone who they xfered me too.

Ole Spiff

Any mass production assembly process puts together a unit from a collection of parts out of bins. These parts are intended to be made to a designed "spec" but in reality a certain amount of "tolerance" is allowed which, depending on how critical accuracy is, can be anywhere from within 10% to 3% of "spec". An average would be about 5% tolerance. That means any unit assembled can and will be made of parts that are somewhere (plus or minus) close to design specification.

A "lemon" is an unfortunate assembly that had bad luck and got a collection of components that were mostly at the low end of accuracy and thus doesn't function all that well; this can include parts 10% under and 10% over which would make for a not-so-good match-up in final assembly. It doesn't happen very often but a small percentage of any assembly plant's products will have some of these unfortunate assemblies. The opposite is true on the good side where a very few, and it's rarer than the bad units, will get a "golden" combination of components through random luck that just happen to be very close to spec...virtually a blueprinted assembly. It's almost like getting the winning lottery ticket.... it does happen which is probably the explanation for the guy's engine who is getting 200hp while everyone else is getting an average of 180. Now keep in mind that the important factor in a golden assembly is how close the various components match each other in tolerance; in otherwords if they are 3% under spec that's not bad if ALL of them are 3% under. The real diamond is that very rare assembly that gets parts so close to spec it's practically a blueprint assembly. Those are often spotted in QC as they'll stand out in testing above the others by quite a bit. They usually don't make it out the door as those are often pulled and taken apart by the engineers to find out why it's performing so much better than the normal assembly....they learn from it.

Some people get better than average gas mileage because their engine was built with parts that matched up better, while others get worse than average because their engine was built with parts that didn't match up so well. There's nothing sinister or "conspiratorial" about it, it's just the reality of mass production tolerances.

As far as the dips in the graphs of the RX8's dyno runs, as Jim Mederer explained it when I was down at Racing Beat listening to him explain his development process for creating an ECU mod, Mazda has created several different maps in the ECU that kick in at various rpm's AND gears. So there will be (I think he said 4 if I remember correctly) maps changing in each gear as you go up the rpm's, and those maps are different for each gear! This is why it's proving to be quite difficult and time-consuming to develop an ECU mod that's worthwhile. As he said, you can just brute-force a change for one specific goal but it would mess up the balance elsewhere. He's taking the time to understand what each map does at each point for each gear so any changes he makes will be truly a balanced improvement, and legal. The guys at RB not only want their stuff to work but they want it to be street legal and emissions certified. This is why it takes longer than other manufacturers for RB to come out with a product. But the results are worth it. Their intake is a solid piece, a marvel and delivers as promised.

I tell ya....when Jim finally gets a worthwhile ECU mod it's going to be a beauty!

DARKMAZ8

hmmm. Is this a future product or just something in the air?

Ole Spiff

He's working on it....has no idea when it would be available; RB never gives that kind of info anyways on something in development. But it is planned to be a future product.

MadDog

This is strange. Shouldn't the ECU sense the influx of more air and compensate to get the same A/F?

Here's a thought. Maybe the REVi, isn't that much better at getting air to the engine. Maybe its just changing the flow around the MAF and changing the effective calibration so that the ECU is tricked into running leaner. That would explain the increased HP and the leaner readings on the dyno A/F sensor in the tailpipe, wouldn't it?

-MD

Mazmart

iTrader: (12)

Polak,
Nice meeting you last weekend (Rotary Revolution). Sorry I didn't get a chance to chat with you more, it was almost unbearably cold. Anyhow I'll PM you or something sometime.
Paul.

r0tor

iTrader: (1)

That would be my guess - that the airflow around the MAF is now different so at the same voltage there is actually more air going through it... otherwise the computer should see more air and give more fuel i would think

dmp

...that implies the little resisters on Ebay for $20 which 'fool' the ECU into thinking their is less air would work.

MadDog

makes sense to me. damn... Is this a way to tune even the close-loop RPM ranges? kinda makes sense. Why wouldn't a voltage divider reducing the signal from the MAF by 10% make it run 10% leaner? I suppose the MAF is where the ECU makes its estimate of the A/F. Is that true?



-MD

r0tor

iTrader: (1)

well the e-manage isn't too much more then a resistor that varies with rpm and engine load...

i'd venture to guess that the ecu wouldn't like seeing the resistor in closed-loop control and should richen itself after a few trips like several CZ owners experienced early on (which makes me wonder that if part of the gain really is from the REVi is tricking the MAF that those gains will diminish over time... maybe thats why racing beat claims 3 hp and Polak got 10???)

dmp

...$ound$ like we'll need a complete $tand-alone....

DARKMAZ8

It's too bad that you have to take off the bumper to install cause as you all know I want to compare the trap speeds and this would be a lot easier if istallation was faster. I say screw dynoing the 8.

DARKMAZ8

looks that way doesn't it.

dmp

Aren't ppl saying the bumper comes off and on in 30 minutes? something like that?

DARKMAZ8

Yeah something like that. I'm sure it's doable but convincing polak to go to a track and beat on his car for us might be a little unreasonable. Hell, I want to buy the intake too but I still want to see if this is worth the $400+canadian. Maybe someone else that already purchased the intake can be the guinee.

dmp

We've got a guy local w/ the intake...maybe I can talk him into it

DARKMAZ8

Maybe if we all pitch like $5 each we can get someone to do it. Heck, I'll do it if someone supplied the intake

r0tor

iTrader: (1)

why? My CZ settings have remained unchanged for 7 months now... as long as you don't screw with closed loop ranges the computer won't know anything

mlx8

Already have done before vs. after dyno results in 2nd, 3rd & 4th gear comparing the RB LWFW to a stock flywheel. The torque graphs are posted in the flywheel thread.

Magic8

My AFR readings are unchanged since last year on my CZ.


BTW you guys could test without the bumper. Sure it looks funny, but you only need to change out the bumper one time. Keeping the conditions same from test 1 to test 2 will allow you to detect changes.

army_rx8

i go tmine off in 10 :D..not hard at all

shaunv74

Racing Beat mentions that due to manufacturing variations in the plastic intake pipe shape it was difficult for them to reverse engineer what the true intake pipe diameter was supposed to be. This may be why there are variations from car to car that cause some people to run leaner and make more power than others. Does the PCM have to assume a certain constant intake pipe diameter to calculate the cross sectional area in order to make the mass flow calculation? If the effective cross sectional area of the stock pipe is less than the computers model than it would assume there is more air flowing at a given intake velocity than there actually is causing it to inadvertantly dump in more fuel to maintain what it thinks is the correct mixture. Is this a plausable explaination for some of the variances from car to car or does the feedback from the O2 sensor help compensate for that?

dannobre

iTrader: (3)

Any changes in airflow will be adjusted in closed loop mode...to go to the set A/F value.
Any Long term changes will affect the long term fuel trims...which are stored by the PCM.

The open loop areas are not feedback regulated in the same way. This allows a piggyback, or any changes in the intake that allow more airflow to change the mixture that the PCM thinks it is getting based on load and RPM , and throttle position mostly.

There seems to be variations in the MAF, IAT sensor, Barro Sensor etc. that make for much intervehicle variations.. and like Ole said above .......some of us are luckier than others in the interrelationship of these sensors

PoLaK

iTrader: (1)

I suppose you've all waited long enough. I GIVE YOU DYNO's!!!!

Once again car was kept in the same position on the dyno, after the stock run, while the intake was installed. Due to it having to be moved while we installed the RB exhaust we only could duplicated the numbers not improve upon them. Look to the name of the Run File to describe the lines.

RB Intake and RB Flywheel+MS Clutch and PP Dyno's below.