What dyno was this tested on? It seems way too optimistic for the WRX, which makes me wonder about the Evo results. If you were to assume the WRX had 227hp then that would equate to about a 16% drivetrain loss based on those dyno numbers. Using that same number for the Evo would give you about 273hp to the crank.

Mark

 

I am wondering how did you get that number (14.76% for losses)? AWDs usually have a bit more than the RWD/FWD cars, which are usually around the 14-15%. AWD cars should be around 18% and that is what was making most of the sense so far. And that is what this 230 - 271 is pointing to, not 14.76!

Fedja

 

Actually, MrAWD when I do the calculation on percentage loss for that it's ~15.13% ... not the 18% you said it was pointing to.. the 14.76 is a wrong calculation for 230/271.

 

Based on the wrx #'s the 273hp seems accurate. If the wrx on that dyno pulled a 165hp then there is something to celebrate about

 

So, what am I missing here?

230 x 1.18 = 271.4

or

230 x 0.18 + 230 = 41.4 + 230 = 271.4

also

271 / 1.18 = 229.66

Anyone care to help here?

Fedja

 

Doesn't look right. You have to take the percentage loss form 271hp. Sort of guessing game till you match the 230hp.

Your taking 18% wheel hp loss or does that translate to 24% flywheel hp loss? Which ever you do depends on what your drivetrain percentage applies.

 

(271-230)/(271) = .1513

calculating loss from flywheel hp to wheel hp

 

Shouldn't it be:

271 * (1.0 - 0.18) = 222.22

I think that gives the amount of hp remaining after drivetain loss (assuming it's 18%) is taken out.

Mark

 

That looks correct buy i think that dyno looks to optimistic and the drivetrain loss on AWD car should be higher than 15% consider 12% on rwd car is excellent.

Problem is we are uncertain on two variable. Friction and Flywheel hp. Actually we can calculate the friction like the aphextwin84 has done but is it really 271hp? And Why is that dyno # so high. I think they messed up like what SCC has omitted on correction factors on the dyno. I recalled SCC had high numbers at one point also.

 

both ours are right KK, which give hope that if it really did dyno at 230 and the drivetrain loss % is similar to previous which has been said earlier around 18% (not sure on this) it should be about 280.5hp

although I will say that it does make perfect sense that if the dyno is too optimistic then ~222 sounds like a good number that it could be up from which probably makes the most sense. So basically you can assume that 222 is probably what it should dyno to and we are probably truthfully getting ~271 at the flywheel... yay US regulations

 

Thanks for the corrections!!

Fedja

 

remember, MMC has a tendency to underrate HP, so I have no problem believing 230 whp in the Evo8. I have seen dyno sheets on the WRX from 165 to 175 hp, depending on temp, elevation, gas etc. (and there are a TON of WRXs in Minneapolis - like hundreds)

 

What kind of dyno and under what conditions was this tested? DynoJets tend to yield higher results than Mustangs, etc. And weather, even though it is "corrected" out, can affect the result, especially on a T/C car with intercoolers.

 

true, but most dynos tend to underrate "real" hp because they are in indoor areas and tend to be hot with little airflow that is so critical to cars with forced induction. unless the Evo was dynoed in some wierd extreme condition, the 230 mark is an excellent baseline to work from.

 

I figured somebody wouldn't believe me, because as you say it proves everybody else wrong. Well, everybody else just may be wrong. I never said the set HP loss was correct, just more correct. Read this, this guy knows his ****.
http://www.vishnutuning.com/dyno_myth.htm