[s-cars] article on horsepower conversion, rwhp to flywheel

[Trevor rice]

The guys from the puma racing site are know a great deal about tuning etc,
but i'd be very cautious of any equations which assume a std transmission
loss.

Your best bet without taking the motor out  is to use a rolling road & see
what the power drop is when the throttle is closed after a full power run is
complete. This won't be 100% accurate as you probably don't have an exact
1to1 gear ratio between wheel & gear selected, nore can u guarantee
sufficient traction.