I know whp is all that matters. But I am trying to figure out the crank Hp with this car due to the 18-20 % drive train loss. I am sure we have a bunch of smart guys that can figure this out. according to my calculations (tell me if I am wayy off ) My car bone stock dynod 237 whp
and now 308

300x 0.25 =75
add 75 at whp 300 which equal 375 @crank make sense?
But my tuner told me that 300whp or 310 is almost 400 at the crank?
also what should my strap speed be in the 1/4 mile with this power?
Thanks

 

I can't help you with your "strap speed," but you're probably making about 370-380 hp at the crank.

 

Don't add or subtract. Only multiply or divide.

Try this:
300crank / 237whp = .79
308whp / .79 = 389crank

So there you go. 389 crank hp.

At least I think that's how it's done. Math was never my strong suit.

 

In your example the 300 crank should be 276 as the whp of 237 is stock...

237 / 276 = .85 or 15% drivetrain loss
308whp * 1.15 = 354.2 which should give you your estimate at the crank.

 

He's got an STI, not an Evo. 389 is about what it should be.

 

WTF is he asking this question on an evo forum then?

 

But I wish I had a EVO..
Thanx guys

 

Now that's a good question!

 

A question I'm glad someone else answered so that I didn't have to...

We don't know what STi's trap with certain horsepower, nor do we know their drivetrain loss, but then again...we don't know Evo drivetrain loss either. It's not an exact science...

 

If you have a calculator do this.. 237x1.18 and that will give you crank number okay.
1.18= 18% drivetrain loss.

 

The reason that this *isn't* an exact science is that the drivetrain loss is variable. In other words, just because you have a peak HP figure on your Evo stat sheet, and then dyno out with a peak HP figure that's 18% lower does not mean that your overall drivetrain loss is 18%. It's physics, and it's complicated, but just believe me when I say that it's not a linear function that you always lose 18%.

I'm certain that if you do a little reasearch into this, that you will arrive at the same conclusion.

Sell the STi and buy an Evo already