horsepower

Originally posted by GT40FIED
That's a really general statement. It all depends on the efficiency of your drivetrain. For instance, if a 20% drop between engine and wheels was the case in my car, my engine would've blown up long ago. I dyno'ed at 657hp at the wheels. If I was losing 20% through the transmission (an automatic) I'd be making 788hp at the flywheel (657 x 0.2). This is certainly not the case. So it's hard to tell with a chassis dyno what the engine's making...those are just estimates and for a basically stock car they're not too bad...just don't use them as a rule.

Someone failed math.

657 x 0.2 = 131.4

Based upon your math....the drivetrain is making lots of hp! :o

But yeah, your point is correct. It's difficult to use a dyno result to get flywheel power, or flywheel power to get wheel power.

All that really matters on the road is what's at the wheels anyways, so I'd just stick with measuring that. And what matters more is the power and torque under the curve, not the peak. Specs from the mfgr are all peak, it's really quite useless data if you don't know what the power and torque curves look like.

b