Hey,
nearing beta release with my game and would need to iron out some problems I haven't been able to get rid of, starting with this one.
This is reproducible in the Car demo in Havok 2010_1_0_r1 (quite old I know).
To reproduce, modify m_slipAngle values to 0.3f and m_friction values to 5.5f or even 15.5f (bigger value amplifies the effect).
You can see the effect in this short video, only throttle is applied, but vehicle makes abrupt turns left and right.
https://www.youtube.com/watch?v=HmECHMEt6Ow&feature=youtu.be
Any (bigger than 0) slipAngle value and friction combination basicly triggers the effect, bigger values, bigger effect.
It also causes evil rumble in force feedback at slow speed. Also when I add AI's in my game it also makes the car actually to "drift" (slowly steer) to left or right even when only slight throttle is applied and no actual wheel slipping is happening.
Anything I could do to fix this problem?