MrWigggles

Yes, they are the same units. A private investor owns Bel which owns Passport.

-Mr. Wigggles

rotarygod

Here's an idea just to see how the RX-8 compares on the numbers. Use the G-tech (or whichever device) and record 5 runs in a few different cars (brands, models, makes, etc...) then compare these numbers with the factory specs on these same cars for power and accleration. Then do the same for the RX-8 and figure out an average correction by using all the different vehicle's data. I know that different cars have different losses but this is just for comparison purposes. I bet that the losses for all the cars is actually pretty close to each other and that this number would be a good number to use for the RX-8. Just a thought.

GoBerserk

Obviously that was too complicated for you.

So I'll put it simpler. You did not measure power at the flywheel. Instead you measured power at the wheels and infered the power at the flywheel by making certain assumptions. Some of the assumptions you made have a certain degree of error. In your case, the error caused by your assumptions renders your final conclusion inaccurate and, for the "mazda made up power figures" argument, useless.

Don't claim to have measured something when you think actually measuring it is too difficult.

What people should be comparing is Rear Wheel HP, like your 158, not flywheel horsepower, because no one has measured it. It's too bad Mazda didn't publish any RWHP numbers.

MrWigggles

Here's the answer key:

1. The car is in its break-in period. There is no easy way to put a few thousand miles on the car. Other forum members have experienced and dynoed their car with about 10 extra horsepower from before and after break-in. (Do a search) So I added those 10HP in.

2. Because I am in the break-in phase I don't want to rev it to redline. Mazda's claimed RPM for peak horsepower is 8500, I got to 8250 RPM (and I didn't mean to even go that high). It is not that big of an assumption that more power would be available at 8500RPM. If it is 4, 6 or 8 HP, who cares? It is not that big of a deal either way.

3. Where did I state otherwise? In the test the adjusted acceleration experienced passed 6500RPM to 8250RPM is fairly flat and consistent. That means the torque is constant as well. If that trend remains consistent to 8500 RPM, then there will be 3% more power at 8500.

4. Is an excl4mation point necessary? 1.58Hp is imperceptible. I made it perfectly clear that the 10% value was arbitrary. If it makes you happy use whatever value that puts a smile on your face. I really don't care.

5. Is this a joke? You left out a ton of stuff. Go read the Yaw Power threads and you will see how hard it is to actually do an engine dyno for the Renesis. He has one on an engine dyno and can't get to work properly because the ECU (among many things) needs wheel speed from all of the wheels (which aren't there). He has resorted to doing in-car dynos as the only practical method to determine the power of the Renesis. Once again, do a search.

GoBeserk,

What I don't get are post like yours where you know nothing about the RX-8 and haven't taken the time to research. Plenty of newbies like yourself are just spewing ignorance without an once of thought or research. And for what reason? I very clearly stated what part of my measurements were from the G-timer and what I had derived. Do you think your post makes you look smart? Do you think you have solved a great mystery? You want a cookie? Wait, I have something better ... For the apprehension of one Mr. Wigggles, imposter Engineer, I hereby award you your very own Junior G-Man badge:



Wear it with pride and I mean the following quite sincerely:

The World wouldn't be the same without people like you.

-Mr. Wigggles

MrWigggles

That is a great idea.

If anyone in the Houston area wants to compare the G-timer to the Gtech Pro, let me know.

The important thing is that the G's measured between the two units are the same. Everything beyond that is calculations.

-Mr. Wigggles

Broker73

we are still on this hp thing...............did you bother reading the info on the reason the car has issues being dyno'd............they put out a release...........a client who owns a garage, made a comment to me about newer cars and the ECU's underneath...............they have advanced like your desktop computer the last 5yrs, and it is very difficult to have someone other than the dealership that knows the sytem and all the variables to get an accurate reading...............god you guys, this is getting to the point of being humorous...........stop looking for cover-ups when there is none......but if that is what entertains you, then by all means.......

GoBerserk

So you say no one has flywheel dynoed the renesis. That's fine. So the 10 ponies everyone is claiming to have gained are from the RW not the Flywheel. So you need to add them to your 159, and then take your 25.6% -there's two more horsepower.

The peak power is at 8500 (according to Mazda). I agree that more power will be available above 8250. But you're claiming 212, that's only 26 less than mazda. And now you say 8 isn't a big deal? That's 31% of the amount you claim to be missing.

Again, past the peak torque (in the revs, 5500rpm) the amount of torque will be decreasing. Unless it has two torque peaks. I've seen that weird case before. However, as with most engines even though the torque is dropping off the power will be increasing because the revs increase.

Yes, it is. Do you think any car company anywhere, or any race team doesn't try to squeeze every horsepower they can out of an engine? Are you for real? Actually the engineers at Mazda probably got 238 and called it a day. I mean why spend the time to be able to increase power and not increase weight. 1.58 per 1% wrong your guess is. Say it's 4% (pretty small) wrong, that's another 6.32 hp. Actually it's 6.72 because you forgot the 10 that should be added to the wheels not the flywheel. And if I can use any value I choose 21% that whay when I multiply it all out I get 238.

That is unfortunate. Perhaps Yaw should try a LabView system to fake the wheel speeds. Or run the renesis with an aftermarket ECU to see what it's capable of.

Learn to spell. I mean it's right there in the margin.

Thanks, I graduate from Cornell this spring with a Mechanical Engineering degree with a concentration in vehicular engineering. I've worked personally with an SR20DET on an engine dyno and know first hand how hard it is to get things to work outside of thier donor cars.

MrWigggles

Accidents happen...

-Mr. Wigggles

MrWigggles

Where did I say Mazda was a lying bunch of bastards. If you think accelerometers (i.e. in-car dynos) are a waste of time, start a thread stating so.

This is an information thread. Despite GoBerserk's claim:

In your case, the error caused by your assumptions renders your final conclusion inaccurate and, for the "mazda made up power figures" argument, useless.

I have not made that assertion at all. I don't know where he got that. I said in my first post that after break-in and if I went to redline that it is conceivable that my HP would be within 5% of Mazda's claim.

People act like I called their girlfriend ugly. I am reporting what I experienced.

-Mr. Wigggles

GoBerserk

So I came to this forum because I'm looking at cars to decide what I want to get when I graduate and I was sold on the RX8 based on my experience with Mazda, Mazda's history, everything I'd read about the 8, and the renesis. Then a friend of mine told me that there were some major issues with the 8, something like the A/C was busted and it didn't make any power.

So I thought I'd check it out. What I found was a lot of people making the most retarded, unscientific claims I'd ever seen. So when I saw Wigggles' post I set out to correct some of his errors in order to make the information he supplied more usefull.

I erred in my judgement, however, assuming he was one of those people out there pushing the idea that there is some huge power conspiracy. I should have offered my corrections in a more civil mannrr. I do stand by the corrections I suggested. I think they can help to make his numbers more accurate.

Wigggles,
And yes, it sounded at first like you were calling Mazda ugly, but no ( I reread your orig post) that is not that case. I apologize.

Oh yeah, I can't wait to go to work so I can get my own 8. My protege is still alive with 203k miles. go Mazda!