zoom44

ok i wrote teh title based on his first post. ill change it to something else. how about "is my car slower than other 8s because mazda lied?

dmp

How about: Discussion on HP ratings, Dynos, drivetrain loss...Does the RX8 deliver as promised?

zoom44

how about "can trap speed be used to find hp and is my car slower than other 8s in the traps because mazda lied"?

dmp

Now you're just being silly.

124Spider

Why do you so diligently sidestep the entire issue of the actual horsepower of the typical RX-8?

The only reason to sticky this thread is to talk about the power of the typical RX-8, not dmp's RX-8, or his driving of that RX-8?

zoom44

no i stickied this thread for this reason-

he wanted to blame mazda for his low trap speed. many others want to blame mazda for this and other related numbers.im tired of the blame game without some measure of the truth behind it. in order for us to know if the blame is being placed in the right location we have to know several things which i tried to bring out

a- can trap speed indicate bhp?
answer- no because you have to guess at losses. so it is only an indicator of wheel hp

b- can whp be used to figure bhp?
answer- no because you dont know the losses. the only way to know the the losses is to dyno the engine out of the car and then dyno the car witht he engine in it.

c-what does his trap speed indicate?
answer- that either his car is making less whp than other rx8s or there was an error during his 1/4 mile runs

and hopefully to stress this final point- Mazda advertises 238bhp for the hi-power. it only has to be accurate to within 5 percent. in order for anyone to blame mazda and make it stick they have to prove the hp numbers. If someone has proof that the actual bhp of the high power car is not making within 5% of the advertised numbers than they should show the proof to the community and do something about it. or else they should stfu.

zoom44

and why do people diligently sidestep the entire issue that something is wrong with HIS car.

zoom44

lol yeah

but back to the title of the thread - Does my car not make the advertised HP- i think we can all agree that during those 1/4mile runs your car was not making the hp that other rx-8s do. what ever the number. dont you want to find out why?

rxeightr

Racing Beat has the RENESIS out of the car. Zoom, can you convince them to share with us their findings?

zoom44

here spider i will hopefully satisfy your curiosity-

i believe that the engineers who wrote the sae tech paper were acurate. their number was 231ps or about 228 american horses. i believe that most Renesis engines are quite capable of making close to that number. i wont say definetly they all make that number because there are too many variances in production tolerances. as someone else said in a post awhile ago- you can get an engine with all the best parts all the worse parts or any mix in between.

dmp

of COURSE I want to find out why...it's just as impossible, however, as my actually pulling the engine for an engine dyno.

124Spider

Thanks. See, that didn't hurt too badly, did it?

Again, however, I say that Mazda is being sleazy if the engine typically makes 228 American horsies, so they inflate that by about as much as they legally can. Sure, if that's true, nobody has a legal gripe, but anybody does have a gripe about their ethics if they rate the engine above what they know the engine to put out.

If it were legal to be within 5% of the correct weight or volume for food productw, would you nevertheless be annoyed if it turned out that your favorite loaf of bread, advertised at 16 ounces, actually was typically a bit over 15 ounces, when other bread companies typically were truthful? I sure would.

zoom44

nahh dmp we use the scientific method. experiment. first have someon who has run 95 in their 8 do a 1/4 mile run in yours and you do one in their car. that shoul dshow us if its car or driver. while doing those runs we should also hook up a scanalyser or canscan on each car and log some of the variables like temp timing a/f etc. we should also run compression tests on each car to compare. also we should either get you new plugs or at least clean yours.

zoom44

but it has no purpose in this thread spider. because dmps car trouble is that it appear to not make even what other 8s make. and that depends lets take bread for instance

if amoroso rolls came in packs that said they were 16 ounces but rarely did they hit that number but it was also within the legallly accepted variance i wouldnt care. even if the competitor always added some extra crumbs to make it exactly 16 ounces i wouldnt buy them- because i like my amoroso rolls and i dont like the competitors rolls.

but at the same time i am pissed at chips ahoy's. chip in every bite? yeah there is because the cookie is only like 2/3s the size it was 5-10 years ago. its easy to claim most chips in every bite when you keep making the cookie smaller

124Spider

Well, you and I will have to just agree to disagree on whether it's sleazy for Mazda to claim 238 if they know that it's not 238.

While I don't think there's much in common between the S2000 and the RX-8, the folks on this site seem never to tire of comparing the two, and yet the S2000 dynos at 210 while the RX-8 dynos at 180, despite being rated by their respective manufacturers at 240 and 238 at the crank. If I had chosen an RX-8 over an S2000, basing that decision in part on the supposedly virtually identical power of the two cars, I would be severely disappointed.

I don't really care, personally, since the RX-8 is my wife's daily driver, and she loves it (when she's happy, I'm happy, and I don't need to point out to her that the HP figure is probably a bit bogus :p ). But IMO Mazda would do much more for customer satisfaction, and loyalty, if they were fully honest with the power numbers (heck, 226 for a small coupe is nothing to be ashamed of). I certainly will never again take a Mazda power claim at face value, and I will continue to take Honda power claims as conservative, until experience shows otherwise.

CERAMICSEAL

I felt I had to chime in here, so here goes. It's unfortunate that my favorite company has invited questions once again about their power numbers. It would be better if they would err on the part of conservative figures rather than develop a reputation for misleading.
Here's the scoop as I see it. There are probably a number of 8s not producing quite what's advertised. Are there cars putting down 210, 215, 225 flywheel hp? I would say yes. You would expect variances from all manufacturers but I wonder if it's not a little more commonplace with Mazda. Is it the hand-built nature? I don't know. To the best of my memory the Racing Beat test showed 219 on the particular day that I was there. Some dynos read a little low but it's possible that theirs was properly calibrated (Please don't question what I know about dynos).
On the matter of how two cars rated at the 2hp apart could read 24 apart instead, I would suggest one may be not making all it's claimed power (The Mazda obviously) but that it's not quite the disparity that it appears to be. The differential in the 8 is much beefier than the S2000 unit: The one in the 8 is almost identical in outward in appearance to the FD third gen RX7 while the Honda's is similar to the Miata's. I believe this is worth 10hp. So in reality an 8 probably loses about 35hp in transition to the wheels. That puts some below claims and a few right in the neighborhood. That's my take on it, feel free to agree or disagree, but can we please stop talking about percentages for the losses.

kraeji

All im saying is that I'll never trust mazda again when t hey tell me hp numbers. They obviously inflated it like crazy! It's too bad the mustang is too expensive.

CERAMICSEAL

A Mustang instead of an RX-8? I guess to each his own.

guy321

Mustang GT cost 31k??

guy321

I don't want to harp on this, but have YOU checked your plugs?

KentDawg

So can we get money back since it doesn't meet what is said? like $1000 or $2000?

tee_rx8

U dont think the car can do 238 hp just because of the low torque. I think the car is considered to produce 238 hp when it works up to more than 8000 rpm. Get another car if u want more hp or mod urs 8.

Vrimmick

And my rx8 is very fast...

nycgps

iTrader: (1)

Same output, different rating standard.