Originally Posted by Si B

Who ACTUALY has compared their engine BHP on a dyno to the power in the car? IE run it in a dyno cell (TUV approved ), then on a proper set of rollers such as Dyno Dynamics?

50% or even 40% losses

The rule of thumb / fudge factor / generally accepted figure on the MLR for Evo transmission is 24%, and I bet most Cossie 4*4 trasmission losses are similar.

Most guys on the MLR now only quote the ATW (at the wheels) figure, as the bhp at the fly varies so much with the different operators and rolling roads.

At the wheels is the most important real world figure. Mine on DD rollers is 437bhp, sounds low for a GT35 running 2 bar boost, but that's all hitting the ground, unlike half the dream figures people are quoting if they are using a 50% conversion rate Does that make mine 655 bhp, cool