Yeah, those physics are correct. Its like riding a manual pallet jack. But I dont think that it is something you would want built into the physics. The more the engine has to do itself the more problems you will encounter. I would just develop a script to speed up the rider when turning.
Like I said. You propel with sideways force because of the force like riding a pallet jack. If you stand on a pallet jack and turn the handle side to side (turning the wheel back and forth) you propel yourself forwards. Its just like holding a bike by its seat and steering it back and forth by leaning it back and forth. This also propels the bike forward. But its such a small force that IF you wanted it in your game (for perfect realism) you would put it in with a script or something. Not to count on the physics engine which is already flawed (and by flawed I mean not nature).
I thought centrifical force was when say a person was spinning with an object in his hand, and he suddenly let go of that object and it would go in a straight line…
No. The object is already going in a straight line unless acted upon by an external force. “Centrifugal Force” is how people desribe the force that “throws” the object out. In reality, centrifugal force doesn’t exist. There is a centripetal force that acts to change the objects path from a straight line to a curve. http://regentsprep.org/Regents/physics/phys06/bcentrif/default.htm
…and no, there is no force that speeds up objects that are turning. The pallet jack example uses a force called friction to move it.