Quote Originally Posted by gbaumann View Post
Pickles. Is power loss in the drivetrain always a percentage of engine hp/torque that scales with the engine or does it take a fixed amount of effort to turn the drivetrain at a given rpm/gear? In other words would a 1000 hp engine give up 250 hp to turn the driveline based on a 25% loss factor; a 500/125; 100/25 and so on or do all engines start with a -X loss due to the hp/torque required to turn the drivetrain?
All depends on the efficiency of the transmission, differentials, number of axles being driven. 27% seems a little high to me. I've had my truck dynoed when I first bought it-- it has about 140hp at the flywheel at 2600 rpm and it showed about 120-125hp at 2600rpm redlined at the rear wheels or about 14.29% loss. Which is pretty good.