As there is no friction from the tyres, the red force keeps acting and the car drifts in the red direction, when ideally I only want forces to act in the blue direction. After a while the drifting stops and it only drives towards blue however the red force still acts for a longish time.

I’ve considered applying forces in another direction to simulate friction but it seems a bit hacky. and also might decelerate the blue force.

You need to apply a centripetal force as well as your driving force. Each step, as well as applying the red force in the lookVector, you need to apply the centripetal force in either the rightVector or -rightVector.

The amount of the centripetal force is based on your speed and how tightly you want the radius of the turn. It will be related to how quickly you’re turning using the BodyAngularVelocity.

edit: Made the diagram a bit more detailed. Your BodyForce should exert a force vector that is the vector addition of the centripetal and driving forces.

All three apply in pretty much every situation. Second law is used to derive the centripetal force equation where the sum of the forces is equal to the rate of change of momentum that you’re trying to create when changing the car’s motion. F=d(mv)/dt which is simplified for a constant mass to F=ma.

@BanTech could you explain this a bit more simply please? I’m not familiar with rightvector or lookvector and I happen to have the same issue with my car, except it uses BodyThrust to drive. Any help would be appreciated, thanks

Circular motion and centripetal force can be tricky to explain. I think the circular motion resource I linked to is probably better at explaining than I am, if my original answer didn’t convey it fully.

The main difference when working with BodyThrust is that the force is in local object space rather than world space, so it’s a lot simpler. Centripetal force is applied as the X number in the thrust vector, and the forward acceleration is applied as the Z number in the thrust vector, regardless of orientation.

The RightVector and LookVector parts were to allow acceleration and centripetal force to be converted to world space based on the orientation of the vehicle.