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Discussion Starter #1
sorry I know this is the racing forum but This is the forum were Ifind the people are most knowledgable.. LOL. seriously..

ok here try to stick with me here
Most STI's dyno stock between 225-230 at wheels right. that equals 300 HP at the crank (25% drivetrains loss) so this is the math. 300 Multiply(x) 0.25 equals 75 and u add 75 to 225-230 u get 300 HP make sense? Or u take 230 devide that by 0.75 u get exactly 306 which is crank HP


Now my STI dynod exactly 230 2 times when it was stock.
After My Dowpipe , full exhaust , ecutek and boost set to 19.5 psi

I dynod at 273 at wheels..NOW U take 273 devide that by 0.75 which equals 364 which is my crank HP. or I take 364 Multiply(x) that by 0.25 which equals 91 ADD 91 to 273 and that equals 364!!
which is my final HP # at the Crank!!
Not bad huh... lol I hope u can follow this and correct me if I'm wrong.. but i did include the 25% drivetrain loss
 

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Tailspin said:
sorry I know this is the racing forum but This is the forum were Ifind the people are most knowledgable.. LOL. seriously..

ok here try to stick with me here
Most STI's dyno stock between 225-230 at wheels right. that equals 300 HP at the crank (25% drivetrains loss) so this is the math. 300 Multiply(x) 0.25 equals 75 and u add 75 to 225-230 u get 300 HP make sense? Or u take 230 devide that by 0.75 u get exactly 306 which is crank HP


Now my STI dynod exactly 230 2 times when it was stock.
After My Dowpipe , full exhaust , ecutek and boost set to 19.5 psi

I dynod at 273 at wheels..NOW U take 273 devide that by 0.75 which equals 364 which is my crank HP. or I take 364 Multiply(x) that by 0.25 which equals 91 ADD 91 to 273 and that equals 364!!
which is my final HP # at the Crank!!
Not bad huh... lol I hope u can follow this and correct me if I'm wrong.. but i did include the 25% drivetrain loss



that was a big waste of time doing all that work. who cares what it is a the crank it's whats gets to the wheels the mater.
 

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The engine's output counts more on a technical/engineering standpoint. They get into sophistication factors and crap like that, based on how much hp/liter an engine is making. You could hook up a 800 crank hp 2.0L four cylinder engine to a drivetrain made of cast iron, and end up with like 15whp, but you still have one hell of a high performance engine on your hands.

And driveline % loss seems to be the way to go. By using a %, it does increase proportionally with the amount of power you're making, so really it isn't a "flat" loss at all, it is a moving number. 1250 crank hp with a 25% loss is 937.5hp, actually, so I think you meant 1333hp with a 25% loss would be 1000hp at the wheels. If it really would be or not, I don't know. I'm not an auto engineer, and I don't know if things would start getting weird at those power levels. But from the basic rules that I've picked up, it should be that way.

Check out this thread, it has a link in it that should help clear things up.
 

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Shouldn't the drivetrain loss max out at some point or another? There has to be a point where you really don't need to factor in the drivetrain loss any longer. Let's say that you're making 4,000 horsepower, are you telling me that you'd lose 1,000 horsepower due to powertrain loss? Just a thought :)
 

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There's always been a debate on where the percentage of drivetrain loss becomes static. Surely at 1000hp you can't be losing 250hp through the drivetrain. With that sort of energy it would surely melt the drivetrain parts.

25% loss is a huge amount. That would mean my 350whp WRX was making 437hp. I dont think so.....
 

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Tailspin said:
sorry I know this is the racing forum but This is the forum were Ifind the people are most knowledgable.. LOL. seriously..

ok here try to stick with me here
Most STI's dyno stock between 225-230 at wheels right. that equals 300 HP at the crank (25% drivetrains loss) so this is the math. 300 Multiply(x) 0.25 equals 75 and u add 75 to 225-230 u get 300 HP make sense? Or u take 230 devide that by 0.75 u get exactly 306 which is crank HP


Now my STI dynod exactly 230 2 times when it was stock.
After My Dowpipe , full exhaust , ecutek and boost set to 19.5 psi

I dynod at 273 at wheels..NOW U take 273 devide that by 0.75 which equals 364 which is my crank HP. or I take 364 Multiply(x) that by 0.25 which equals 91 ADD 91 to 273 and that equals 364!!
which is my final HP # at the Crank!!
Not bad huh... lol I hope u can follow this and correct me if I'm wrong.. but i did include the 25% drivetrain loss

dude this is the 2nd time.well 3rd someone else already said it on this thread STOP SAYING RWHP...u have a fawkn AWD car..its AWHP...got it?? ..u dont drive a vette or supra, viper etc etc..u drive a subaru wrx sti AWHP! ..damn it...sorry had 2 rant:mad:
 

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SLOW4EAT said:
what are you a comedian?

i was going to mention something of that sort. but i'm an outsider and didn't wanna start anything. glad someone else did it.
 

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silverscooby said:
There's always been a debate on where the percentage of drivetrain loss becomes static. Surely at 1000hp you can't be losing 250hp through the drivetrain. With that sort of energy it would surely melt the drivetrain parts.

25% loss is a huge amount. That would mean my 350whp WRX was making 437hp. I dont think so.....

I'm guessing if you put a 1000hp ej20 into an otherwise stock wrx, it would indeed wreak havoc on the drivetrain components.:) My best guess is that it won't continue to be a 25% drivetrain loss, cause the entire drivetrain is going to be differenct. I'm sure you'd replace it all with light weight, high strength stuff, all carbon fiber and titanium and stuff.
 

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OffRoadWagon said:
I'm guessing if you put a 1000hp ej20 into an otherwise stock wrx, it would indeed wreak havoc on the drivetrain components.:) My best guess is that it won't continue to be a 25% drivetrain loss, cause the entire drivetrain is going to be differenct. I'm sure you'd replace it all with light weight, high strength stuff, all carbon fiber and titanium and stuff.
My point was that the energy loss of 250hp (assuming it was still a 25% loss) would create so much heat that it would wreak havoc on any drivetrain.
 

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not to be a jerk, but are those number a little low for the mods you have? my friends STI made 301awhp on a dynapack on 93oct. w/ utec, catless TBE, intake silencer removed, and a BOV (good for like 50hp at least!!).
 

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Discussion Starter #20
yes

could be or... the dyno just had didd #'s. I have seen dynos for stock sti's dyno at 240-250 at wheels and some between 225-230 at wheels..
 
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