Need Help with Torque plz

[LuckysGmod]

Hello everyone,
I have a probleme, I'm working on a tutorial for acf helicopter. The helicopter work fine but when i power it with acf (1 turbine connected to a clutch connected to the rotor) the clutch is transferring a part of his torque to the main body with make the helicopter rotating on itself (that is expected).
I'm applying a opposing torque for the moment but the probleme is that this force is not linear and variable therefor i can't effectively prevent the rotation by simple trick.
And it get realy worse when I remove Drag on the engine and the Clutch.
I tryed to calculate this force with acfRPM() acfTorque() acfTorqueout() but nothing look to work.
I also look directly in the acf code but its to advance for me...

I would like to know, how can i with perfect accuracy calculate the amount of torque transferred from the Clutch to the main body so I can apply the instantly the exact opposit Force.

Thank you for any coming help

[LuckysGmod]

I want to know how to calculate the backforce applied on chassis by engine and gearbox plz