I know the automatic has 280 Hp but how much is to the wheels?

 

depends on your car... probably about 230-240

 

+1 always around that

 

around 230........search it for stock dynos and stuff

 

280HP auto engines are 220-230 whp on a dynojet

 

+1

I personally saw an 05 5AT Coupe dyno at 225 last year. I saw an 03 5AT coupe(with stillen intake, unknown exhaust, can't remember other mods) put down 229. So 220 to 230 on a dynojet is typical.

 

What I have always heard, as a general rule of thumb, is that all cars will lose 10% to 15% hp through the drivetrain. In this case, that would equate to about 238hp (approx) to the rear wheels. That would support G.Ride's reply.

 

How about not enough hp

 

That's definately a general rule. G's lose a bit more. It all depends on what the manufacturer "claims" is at the crank and the drivetrain.

 

I've heard about ~25% loss for autos and 18-20% loss for manuals.

 

Thanks

 

its actually 20% loss for autos and 15% loss for manuals.

my 05 at dynoed at 224hp and 215 tq which is almost exactly 20%.

 

It really doesn't depend on the dyno. Every car loses power from the engine to the wheels due to friction and other energy losses in the system. It's physics.

Dynos differ in their reported wheel horsepowers too, but the % loss of power from your engine to your wheels is a function of energy loss. Auto's lose more because they are not as efficient (more loss occurs in the torque convertor).

 

^I think he meant it depends on which dyno meaning that each type of dynop gives out different readings. Dyno #1 might say you lost 15% at the wheels, while dyno #2 will say you lost 20% at the wheels because one compares the value given by the dyno to the avertisded HP, which is also only an estimate. The problem is no two dynos are exactly the same and too many factors play a role in power readings to get an exact figure for HP lost, even for the matter of fact HP you have in a car.