mac

Hi Adam,

Could you scan the output and post to the Tech Garage? It would be greatly appreciated. Did you return to the dearlership and asked them if there was anything wrong with the car?

Thanks,

MrWigggles

adam,

No one is trying to give you a hard time. We are simply looking for more info. Try not to take it personal.

If you could scan the dyno chart, that would be most excellent.

-Mr. Wigggles

Digisan

Per the RX-8 press event:



Q "How much horse power does it make to the rear wheels?"

A "About 204-207."


Link


Something isn't right with your car or Mazda is lying.

seikx8

We'll just have to wait until people get their car and start their own verification. Perhaps some one at mazda put the lower version into that car (it only take a person in their sleep to do it) :D I can't wait until mine is broken in and bring it in for a dyno, then to the track.

tribal azn2

calm down guys. i would take that dyno with a grain of sand. i remember when the evo first came out, some stupid tuner dynoed it and got 180hp when all the other tuners were getting much higher. this dyno is simply wrong. just wait for more dyno results, i am positive they will show the true hp.

MrWigggles

I wouldn't dismiss the dyno that quickly.

-Mr. Wigggles

RX-Hachi

Well something's not right, either his car or the dyno.

Hmmmm, could it be the dreaded sticky port issue is not really resolved? Or, is it possible that a 207 hp engine was wrongly mated to a 6 spd MT in some production line screw up?

It just seems too odd that a supposed 247 hp engine dynos like a 207 hp one.

RomanoM

Adam,

Don't take this as a wiseass question, please.

Did they turn off the DSC? Assuming you have DSC.

If not then the dyno run is useless since the traction control will attempt to regulate power output as the front wheels aren't turning at all compared to the rears spinning like crazy.

Also, with DSC you need to be careful as many of the legal departments (including Ford) are demanding that the off switch not be a true off switch. Just that it makes the system less obtrusive. So, the DSC and TC are always there working behind the scenes.


Thanks

RobDickinson

1 press to switch 'off' unless ABS comes into play 6 second press and hold to completly disable DSC until you restart car.

Dyno's are only good to compare against their own results and at that time, if the car peforms (*i.e. goes as quick as it should on the roads) then who cares?

rxtreme

iTrader: (1)

We definitely need to see that dyno chart. It would let us know if the ports were actually stuck and maybe if the DSC was on during the run. Also, I would like the details on the dyno shop you were using. What are his procedures on dynoing the car? How many pulls? Hood up/hood down? What kind of dyno was it? What gear did he use for the actual pull? How did he varify the accuracy of his temperature and altitude adjustment sensors?

There are alot of ways to make a dyno lie and if an owner doesn't know what he's doing, it can really screw up the the results.

RomanoM

Just FYI - Since the control software decides all these things and since only the Mazda and brake supplier actually know for sure this is just FYI.

But. many systems I've worked on when I was brake engineer NEVER actually turned off at all. They simply went into different states. Even the systems that claimed if you hold the button down or hit twice, etc., never actually shut off. They would intrude at very high thresholds, but they will intrude. The Jags for instance are set up as such. Even the Corvette keeps the yaw control working all the time, albeit at a very high threshold, since the car is so easy to spin under power.

Again, I am NOT saying the RX-8 is set up this way!

beaner

Isn't there some other place on the forum where there is a link where they are hooking the engine directly up to a dyno?

Maybe we should wait for those results, since they will completely take drivetrain losses out of the picture.

brillo

Adam,

my comments were not directed at you personally, your numbers are what they are, and you had nothing to do with them other than paying for your dyno. After having looked at many dyno's including the RX-7, I see no reason why it should be this low. I would consider taking your car to another place with your first dyno and see if they could run you (hell they might do it for free just to see your car). Make sure A/C, DSC, traction control everything is turned off

RotorBoy

One dyno test does not a scientific result make.

P00Man

sounds a little strange to me...and i dont really know all that much about it...but since "normal" losses are around 17% and his loss was somewhere near... 26% i think it was, something cannot be right...

anyway, theyll be a lot more dynos soon so well know...
i really doubt mazda has screwed anything up, they have too much riding on this car and have been testing it for too long to have something like this happen, i think its just some human error and nothing to worry about at all
________
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Gord96BRG

Bwaaaahahahahaha!!! It's barely to the point where you can start using full revs. "Broken in" in terms of an engine producing it's full rated power usually takes a few thousand miles. There's plenty of cars out there that are well known to need over 5000 miles before they 'loosen up'.

Try it again when you have 6 thousand miles on it, not 6 hundred. Oh, and turn off the DSC. Your current dyno test was pretty much useless. No, actually - it will be useful to illustrate just how much extra power it is making after it really is broken in.

PS - drivetrain losses are not a straight percentage. For a given drivetrain there will be certain fixed losses, and then if adding additional power beyond a certain level there can be variable losses. For example, thousands of dyno runs on Miatas have shown that drivetrain losses (flywheel to rear wheel) run around 26 hp. NOT 20% or any percentage. So if flywheel HP is 116, it dynos at 90 hp. If flywheel HP is 128, it dynos at 102. If you add a turbo and are producing double the HP, then there are losses beyond 26 hp, but it doesn't jump to 52 HP in drivetrain losses as you'd expect if using a simple percentage number to estimate the losses.

Regards,
Gordon

chikai

1) Adam...don't take any of the above comments personally. People's negative reactions were at the incredibly low number, not at you.

2) I remember when I dyno'ed my car the tech told me it wasn't possible to dyno the E46 M3 correctly. It had a sensor at the front wheel that detects rotation, and if there was no rotation than it cuts off fuel at a certain RPM.

Adam...did you notice when you dyno'ed that the car it was cutting out before redline? Or did it seem like it was lagging a little?

Also what gear were you in? You want to be in the gear that is closest to the 1:1 ratio between engine speed and drive train speed (which according to the Mazda site is 5th gear!!!...wow).

OrangeBingo

The typical loss for a RWD car producing RX-8-esque horsepower is 17%. Yes, this percentage does vary depending on a number of things, but not by much. And the formula just happens to be slightly more complex than you seem to realize, one does not simply double the frictional losses when the horsepower doubles. Geeze, did you really make me say that? I would have thought it was self explanatory.

Red Devil

I don't see it as a big deal if the car only produces 174rwhp, just as long as it performs similarly to what the various magazines tested the car at. Just my thoughts.

At the same time, my concern would be whether my personal car was not mechanically sound, or if Mazda's factory information is not correct. The last thing Mazda needs is a scandal, and I assume every one on this forum can agree on that.

adamp316

again... they didn't put the 207 hp engine in mine.. there is 3 ports. the automatic only has 2 ports. Second i told you that they dynoed it in 3rd and 4th gear. And they weren't stupid, they dynoed it with the dsc abs off and the ac off. ANd for all you who think i payed.. i didn't. the tech was so happy to see one and look at it he put it on there for free. I cant go back to my dealer because its in orlando and i live in Boca. I cant scan the results because im not home. Im in key largo and well the results are in boca raton.. I got it dynoed at petit racing so u can call for your self if u dont believe me. they only do rotary engines. they specialize and make these rotory's called banzai's or something.. they produce like 550 HP. that should answer most of your questions. i should be back tonight and try to scan it

Quick_lude

That can't be right. Either because it's not broken in yet, and at 600 miles it is NOT, or the dsc was on or the dyno was setup wrong. Preludes have 195-200hp and dyno around 160whp.

mac

Thanks for taking the time to post while traveling.

Keeper

As a couple of people mentioned, your engine won't be making full power for a few thousand more miles yet.

I know of once instance where a guy dyno's his eclipse right after he got it and came up with about 110hp to the wheels (for a 200hp car).

You *will* know when the motor wakes up; you'll be driving around one day and you'll be wondering why the car feels like it's kicking some *** all the sudden. It takes a couple thousand miles, and while it won't wake up instantly, it is pretty quick process once it starts.

Gord96BRG

So, first you say it's a percentage... then you say it's not a percentage. That's very self-explanatory, thanks! The use of a percentage should apply when it's actually a percentage - sure, you can divide any number by another and express the result as a percentage, but unless it truly is a fixed percentage which would be scalable, then that's an entirely inappropriate use of that function. To say "powertrain loss is 17%" means that it's 17% at 116 flywheel HP or 17% at 232 flywheel hp. If it's NOT (and it seems we both agree that it's not), then expressing powertrain loss as a percentage is just plain wrong. It's not more complex than I seem to realize - that's why I initially wrote to say it's not just a percentage, because I do understand that it's complex.

However, I've been through this debate on several other forums (especially on the Miataforum), and I know that it's pointless to argue this just like it's pointless to argue religion! So I'll leave it at this.

Regards,
Gordon

RX-Hachi

I'm just stupid about such things, but how do you know for sure your engine is the 3 port 247 hp one (other than the fact that the 6 spd is "suppose" to have it)? Can you tell by the external look of the engine? I didn't think they looked any different from the 207 hp one on the outside. Or did the dyno results show something to indicate 3 ports? Actually, I'd be more concerned about the 3rd ports opening correctly, as the pre-prod cars had this problem.

Also, you seem to be more upset with this forum than the actual results. Are you pleased that your car will be in a mag write up? That's the last thing I'd want with such crappy dyno readings. If I were your shoes, I'd march right back to the dealer, slam down the dyno results, and demand Mazda fly in their top engineers to find out what's wrong with your car!

Why not do a couple of 0-60 runs to see how close you can get to 5.9 secs. That would give you another data point to see if your engine has a problem.