Actually, while the 15-20% that everyone throws around as a loss/gain is rule of thumb, the rule is inaccurate at best.
Example, my last 346" driven M6 went 460rwhp/424rwtq. Let's use 20% as the loss(rwhp x 1.20(20%)= 552 FWHP)through a heavy ass driveline.... steel DS, 12 bolt/4.56's, and 28" slicks.
Swapped in a braked stalled lock up TH400 and went 440/400 which shows a loss of an additional 20 rwhp.
New motor w/the same TH400 went 540/500(648 FWHP, again using 20%)through the same driveline. So.... if I swapped the same M6/clutch & flywheel back in it would go 81+ rwhp more? The math says not.
Driveline loss is drive line loss, and is what it is. It doesn't increase exponentially with power increase. That would be like saying it would take 300 FWHP in a 2000 FWHP motor to turn the same driveline I'm turning with 108 total FWHP in a 648 FWHP motor
I could understand and agree that when going to an unefficiantly built trans/converter combo, or even add in gearing/tire combo's the loss would increase(or decrease), but I don't buy the 15-20% across the board blanket statement for every application.
I HAVE done the math.
Back to Chris being full of shit......
He is not.
Have a nice day
