mathematical model of vdrift cars

[flo]

No, that was not what I meant.

If you look at the equation in clutch.GetTorque (in carclutch.h):

new_speed_diff = engine_speed - drive_speed

There is on the one hand the engine speed, calculated from modified euler method in rotatinalframe and on the other hand the driveshaft speed computed "backwards" from the wheel speed over transmission to the clutch. The difference is multiplied with the maximum force at the clutch, which leads to a friction force. But this result is only active if new_speed_diff is between (-1, 1), elsewise the friction force is set to (-max_force) respectively (max_force). So if the current drive_speed is bigger than the engine_speed+1(both forward speed), you get in return -max_force, which in turn is getting positive because of the minus at the total torque.

total_torque = combustion_torque + friction_torque - (-max_force)
(with max_force from clutch)

What I meant in the last post was, you are driving with forward speed, but without use of the throttle at the moment you get something like this.

total_torque = 0 + (-small_friction_value) - (-max_force)

And the engine would accelerate because of the high torque from the clutch, without any use of the throttle.
So in my opinion, the clutch.GetTorque function only make sense, if new_speed_diff is really small and engine_speed is bigger than drive_speed, than you can see it additionally friction force.

I hope I made my problem more obvious this time :-p