Fantastic help you're giving out, pickle.
// Engine
engineTorque = 12000; //4000; // Engine power
engineBrake = 2000; // Braking when throttle is 0
brakeTorque = 50000; // When brakes are applied
maxWheelSpeed = 30; // Engine scale by current speed / max speed
You most likely want to edit this part in the JeepVehicle datablock. In particular, you would want to change maxWheelSpeed and EngineTorque.