Can someone explain to me if there is a relationship between Engine Horsepower and Rear Wheel Horsepower? In other words if I was attempting to produce 700 horsepower at the rear wheels, how much horsepower would the engine have to put out?

Thanks.

 

LT1 Tech is a good forum.



Its all dependent on tranny, reciprocating weight of drivetrain and rear end.

 

For these cars people seem to use 13% drive train loss for M6, and 15-18% for A4. It will vary however with how much HP you are making altogether, and the rear end being stock or not. 9" Ford costs a little more than a 12 bolt, and a TH400 will suck more power to drive it than a 700R4 or etc

 

You need to do a "search"... there have been several extensive discussions on "drive train losses". And these same topics have been discussed numerous times on LT1 Tech.

Obviously, RWHP = flywheelHP - drivetrain losses

Drivetrain losses are often expressed as a percent of flywheel HP, but you will find that while you can make generalizations, it depends extensively on the specifics of the drivetrain, and the power level being transmitted.

For an M6, you will find that losses might be around 14-15% on a stock setup, and 12.5% on a very high HP (and that would be 700RWHP) setup.

For an automatic, depends... you might see 16-18% in a 4L60E on a stock engine, but you probably need something like a TH400 for 700RWHP, and now you are looking at something more like 18-22%. I found that my 783flywheelHP setup produced 689RWHP with a T56, and 617rwHP with a TH400. Performance was surprisingly not affected a whole lot.

Since there is already extensive material available, and this isn't really an "Advanced Tech" thread, I'm going to lock the thread.