[TN0908]

What "percent" drive train loss do you calculate when you determine horsepower at the crank. Also torque.

 

[nismotony]

I believe that the normal commonly accepted nubmers would be to have a 15-20% loss in hp and torque from the flywheel to the drive wheels.
Thus if the car dyno'd at 200hp at the rear wheels (using the 20% rule) the actual horsepower would be: 250hp

using 20% rule calculate like this:

rear wheel hp
-------------------- ~= flywheel hp
.80

Same goes for torque since a chassis dyno measures hp, then calculates torque by:

HP X 5252
----------------- = Torque
RPM

 

[yurmohill]

dynos don't win races.