This topic will always have disagreements.



-As a RR measures power @ the rollers,
-hub dyno's measure power at the hubs, which is different to power @ the wheels.
-Engine dyno us the only accurate way of doing power at fly.
and all need to done correctly on the right dyno mode/settings.



i believe power losses is not a set bhp, due to it being a resistance. so more power at the fly, the more lose.
But i also agree that Most RR's quote incorrect power losses from fly to wheels.



NISSAN MOTOR COMPANY, quote the power loss on their Pulser GTIr to be 77bhp from fly (227bhp) to wheels (150bhp), which is 34% losses.


Also the gearbox isn't the only thing that causes losses, Props, driveshafts, cv and uj joints, wheel bearings, tyres, and all the rotateing wieght of the whole lot.