Jake951

I saw this posted on Bimmerforums and thought it would be of interest here, too. It's a calculator for 1/4 mile ET and trap speed, based on just hp/weight ratio. Go here to take a "test drive". There are actually 3 different calculators there, all based on empirical formulas.

The "LRT" calculator provides the overall "best" match to a broad collection of data from Road & Track road tests. For a stock Turbo S (3200 lbs. est. and 247 hp) this calculator predicts 14.4 sec @ 98.4 mph. Back in 1988, Road & Track got 14.2 sec @ 100.5 mph, so the LRT calculator slightly underpredicts performance of the 951S.

What about a modified Turbo S? At 300 hp (keep in mind this is crank hp), LRT predicts 13.6 sec @ 104.6 mph. This would correspond to Turbo S with some decent chips. At 350 hp (my car with MAP), the numbers are 13.0 sec @ 109.8 mph. Given that the LRT calculator underpredicts a stock Turbo S, I would expect these numbers are a bit conservative.

Let the bench racing begin...

atinybug

this is assuming everyone's got the same gear ratio, same size wheels, etc etc. but woohoo! 12.4 sec @ 115 mph go me! (in actuality, probably closer to 14.0 cuz i'm gonna launch like a granny so i dont break stuff)

porshhhh951

The LRT says 12.310 s @ 116.83


Ofcourse who know's how acurate this really is.

still very good fun.

Tomas L

From what I've read, terminal speed should be a good indicator of engine power (vs. weight) . The E.T is dependant on many things, tire grip, chassis settings, gear, driver skill, etc. Terminal speed is more insensitive of these other factors.

Tomas

Darius Juca

damn I though I would get better than low 12's in mine..can't be right!! or maybe it is.. scared to try it..i saw the video of the broken cv.....

emwporsche

12.4

remember that bhp is to the flywheel
so I added 11% to my rwhp

I have no lsd so I would really get a 13.7 or something!

atinybug

oh, well in that case, 11.7 @ 122 mph
hehe