finitialdriveforce

can anyone tell me how do i transfer real vehicle power into finitialdriveforce value?

So far it doesn't seem like there's a direct horse power or torque to fInitialDriveForce conversion. From messing around I found it to behave more (most?) like torque, but I couldn't figure out the units. The torque "curve" (basically just a ramp up and a constant torque) also doesn't really follow the "real" torque curves. (Correct me if I'm wrong).
Add to that the 0.2RPM to 1.0RPM values of the game and the default fixed gear ratios (with a "final drive" that depends on your fInitialDriveMaxFlatVel) , and it's pretty hard to translate real data into game data.
Your best bet is to measure acceleration times (050, 50100, etc) and tune fInitialDriveForce and fInitialDragCoeff to match a cars' acceleration data. Also take in account wheel slip and things like that, as those might negatively impact acceleration times.