In options >> advanced : you have sliders
Gforce : put it completely to the left to disable driver head movements in all directions. I like to feel my virtual body when I brake/accelerate so I set more than 50%.
Look-to-apex : must always be at 0 completely to the left (head turn left/right to follow steering wheel direction if you enable it). I set always 0 because I don't like that.
World movement : to the left the cockpit is fixe but world horizon is moving, to the right the cockpit moves but horizon is fixe. I set 50% but for VR some people recommend 0.