...i guess you've never seen a Honda dyno sheet (most notably, one for the F20C) :p

...did you do the math?? and also, have you looked at the factory dynographs?? peak power comes right at redline, so the torque difference isn't 20ftlbs large, nor is there suppost to be a jump: the curve just isn't suppost to level off and turn down until 8500 rpm.

Probably to stay in the nice emissions friendly low lift cam for epa testing.

So you're saying the torque curve will peak around 120ft-lbs around 4-5000rpm just as it does now, start to dip around 6000 just as it does now, and then at 6250rpm start a linear rise from about 115ft-lbs to 135ft-lbs or so at 8000rpm before going back down to 130ft-lbs at 8500rpm?

Even if it is linear, the engine spools up so quickly that a 20ft-lbs increase over 1500rpms would feel like a spike. 1500rpms for a rotary is like 800rpms in a normal piston motor- you'd get a 20ft-lbs increase in force in about half a second's time in first gear, even though on the dyno the increase would look linear.

To make 207whp at 8500rpm, the engine would have to make nearly 20 more ft-lbs of torque than the dynos currently show at 8500rpm- that's about 128ft-lbs. That's where I got the number from. Since 128ft-lbs is more torque than the engine currently produces ANYWHERE and 8500rpm isn't even the torque peak, you can see why I think the entire graph is low and not just the top end.

I'm not suggesting there should be a peak- quite the contrary. That's why I think the entire graph is reading low, which lends itself to the theory of the ECU only allowing ~90% throttle or something.

oy, i'm not arguing this BS with you... and peak power comes at 9000 rpm from the original Mazda dyno sheet.

I thought you were some veteran here- crap, I've been reading your posts forever on this site. Peak power is claimed at 8500rpm- 9000rpm is redline.

In fact, this graph shows a pretty close torque curve match too discussed here.

Okay, my car now has 44xx miles on it and this week I will dyno it again and post the results.

Vince

Excellent

Do one run in 6th to settle the argument about the dyno not having enough load time for the flow to stabalize.

...funny how you say that, then cite the thread i went ahead and plotted all those curves together in :p

I edited my first post with new graph and data.

Completed new dyno runs today (9-3-2003) 10 degrees cooler and 10% more humidity.

Substantial increase in both horsepower & torque. I also did runs in fourth and fifth gear and they were within 1% of run 002.

Vince

Your updated numbers look better. If we assume a 22% loss, which seems high, I suppose this looks more like what Mazda has stated.

So, the parasitic loss is still about 22% from the stated 238HP figure. Can anyone comment and give a synopsis, as to good, bad or indifferent.

Hey Vince, sorry for sounding stupid but how do I see your updated numbers

huh, interesting that the entire curve showed the ~8-10 increase, not just at higher RPM's...

~10 deg cooler, 10% more humid, and an extra 2k miles.... :eek:

I updated my first post.

Vince

Next time try 87 octane and maybe youll top this guy's run, which i think is the highest dyno weve seen yet. Youve got 2000 more miles so you should top him with 87.

https://www.rx8club.com/showthread.p...5&pagenumber=1

Well the good news is that you are making all the torque you should. I would think that your car should never ( unless modded obviously ) pull HARDER than that. But on the down side, the torque drops off a couple hundred RPMs early, so it's just not pulling strong as long as it should. It is looking better though and i do think there is an easy fix.

Very encouraging that an additional 2000 miles freed up that much power (did you change the oil in that timeframe?).

If it frees up another 10-12 hp you'll be very close to Mazda's 238 hp rating.

SC

Changed it right after the first dyno test.

Vince

fuel?
 

if I missed it I apologize, but the type of fuel in both tests? assuming premium unless stated otherwise.

California 91!

Vince

Hate to be a pain in the ass, but with the original data gone, can we get a quick summary comparing the two?

Ie, peak hp, torque, temperature, miles on the car?

The original data isn't gone. Go look at the updated first post, which compares the old and new runs, including details re temp, humidity, and miles.

Doh. My bad :P The joys of skim-reading the forums with your boss in the room when you're supposed to be doing work ;)

Interesting. Might be worth having other people recheck after an oil change. I do a lot of oil testing for several companies and we've found power differentials of up to 3-4% by changing from standard factory fills to high quality forumlated oils.

Maybe Mazda is using an unusual oil formulation for break in. On piston engines it usually has a high Moly content, but for rotaries I don't know.

SC