KavMan,

My mistake, it was only a 10 hp difference in the 91 versus 93 octane which I guess does make sense. I guess it was a bit early in the morning when I read and responded to that thread.

2GTSiAWD

Thanks for your response. Makes sense then that there could be up to a 30% drivetrain loss on all wheel drive cars.

 

Understood. I already knew that you don't want it too rich in the higher revs... going as low as 10:1 just seems a bit strange, though...

Who knows... Tuners will figure things out. Hopefully I started a good discussion here. I don't know much about good/bad A/F ratios to provide good info. Maybe more people will add their comments.

 

If 91 octane is all that is available in CA, how do you get 93 octane to run your test? Do you mix the 100 octane race gas into the 91 as you mentioned in another thread?

If yes, how you you know when you have actually added enough 100 octane to equal a good 93 mix?

You mentioned previously that you 'splashed in' some 100 octane to bump up the octane rating of the gas in the tank. But to really get 91 octane gas to equal the 93 or 94 octane gas the car requires as per the manual, you would have to add 0.5 parts of 100 octane for every 1 part of 91 in the tank(3 gallons of 100 has to be added to 6gallons of 91 to equal 93/94 octane mix).....which is a lot more than a splash.

SC~

 

Lookin good - cant wait to get my evo !

 

If visnhu didn't have any 100octane gas then they can just go over to Modacar (in the same complex) to get 100 octane.

it's a guessimate on the octane you end up with, but there is a chart you can use to roughly calculate the final octane.

"splash" could be just a figure of speech not a measure of the amount of actual gas that was put in.

 

Splash = approx 4 gallons.

Brett.

 

--bobby

 

Hi Shiv,
Have you heard anything from mitsu regarding power output on the Evo8 ?? Thanks.

 

From the dynos, it looks like from the mild knocking you get about 160hp. I don't think too many people who live in CA are going to want to put 4 gallons of 100 octane gas every tankfull so they don't get knocking.

 

Hey big Al!

Thought you were going with the USDM STi? Were going to miss you in subaru land.


Looks like the s-afc is going to be a huge early seller for evo8 owners, piggy pig rich!

 

Nice torque numbers on the evo. No wonder people are saying it feels fast as hell and faster than a modded wrx.

Has almost the same torque numbers as the JDM evo 7, HP should be just around the corner- I hope.

Can someone explain why it runs so rich or is it normal for DSMs to do so? Did DSMs run that rich stock?


Nick

 

Shiv,

Just wondering... does Dyno Dynamics dynometer works for
fwd/rwd cars?

If they do.. have you ever dyno fwd/rwd cars? How much
drivetrain loss do they typically show for these cars?

Thanks,

 

These pulls are at WOT, nearly all cars (hell, even lawnmowers) will run between 10 and 12 to 1 ratio at WOT. Running at lower ratios creates a "hotter" burn in the cylinder, which is really hard on engine components like piston surfaces and especially exhaust valves because of the higher exhaust gas temp. Plus, the cylinder head temp is much higher, creating hot spots, which ignites the fuel before the spark does. The piston suffers a major backlash from the ignition happening while it is still rising and the vibration can be heard as "ping". In a high specific output engine like the EVO's, all of these problems are even worse because you already have to deal with very high combustion chamber pressure due to the turbo. Hence, the more boost and throttle the computer sees in the EVO, the richer the computer will make the ratio. put this that way to make the engine more durable.

 

The vast majority of the cars we dyno are WRX and 2.5RS turbos. We have dyno'd some stock, or reasonably stock, 2wd cars.

Looking at the dyno graphs on the office wall, a stock S2000 made 188 wheel hp. Stock Type R made 153 wheel hp. Stock 2nd gen Miata makes 100 wheel hp. A Dodge Lightning (auto transmission) put down around 300 wheel hp. The very un-stock Top Secret Supra (the gold-painted wide bodied thing) put down just under 700 wheel hp.

FWIW, a stock R33 Skyline (with the muffler removed) put down 240 wheel hp. The dyno is so sensitive it even picked up the constant back-and-forth torque distribution as little saw-toothed patterns on the torque and hp curves. Stock Porsche 993 turbos have put down 300-310 wheel hp. A stock Porsche 996 turbo has put down 336 wheel hp. The Porsches are nearly impossible to dyno on a Dynojet since they place too much unrealistic strain on the electronic center differentials, making the car buck and tend to leap off the dyno. Those cars make serious power.

Cheers,
Shiv

 

shiv, a little ot but have you dynoed any 240s with sr20det swaps? i was wondering what they put down on a dyno dynamics..
thanks
--bobby