Quote:
Originally Posted by SeanWRT
Crank power is whatever you feel happy with. The way I look at it - it's a 90whp gain over stock car same condition, which is equal to 365+"90~100"= 455~465hp at crank. But unlike stock, GP500 runs super cool and efficient at just 16+psi and is much more consistent and reliable pull after pull at track. Basically I'm doing 90whp more yet leaving more headroom than M2 from factory. I can do 1 or 2psi more to show a better and ego satisfying number, but I chose to show the number that's consistent enough for track use.
M2 has been the all time most inconsistent turbocharged BMW there ever is, thanks to the fact that factory flash already pushes a little out of its turbo efficiency zone, making it highly sensitive to octane/IAT. As a result, USA Dynojet has seen a range of 320~355whp reported from 2016 summer to early 2018. I believe on a cool day and 93OCT, M2 is a 350whp car USA number.
In my case, under perfect condition and good pump gas, stock M2 is 330+whp, M4 base 390, ZCP 410. That's how my dyno reads 15~20whp lower than USA. Stock M2 competition would be 380whp on my dyno at best.
With USA numbers, you'll see M2 N55 doing 430~440whp from STG2 turbo on pump gas tune no issue. And S55 would be doing 450/470whp from BM3 STG1/2 tune.
As for M2 mod vs. M2 competition. My opinion is this
https://f87.bimmerpost.com/forums/sh....php?t=1551866 |
The only reason I’m talking about crank hp is because this is how it’s measured in the UK from a dyno they add a percentage on top of the whp for a drive trailer loss.
You covered everything I wanted to know on this thread and the link above.
So thanks for your input I’ll stop bothering you now, Much appreciated