Weight Transfer In Cornering
Racing car drivers usually talk about weight transfer – weight transfer forward under brakes, rearward under acceleration and from inside to outside wheels when cornering.
Weight transfer concept is critical in suspension set-up, particularly in car cornering. Engineers must know how to distribute weight transfer between the front and rear axis to adjust balance of the car when it is cornering. As a driver, we are certainly unaware of the weight transfer distribution, the only thing we notice when cornering is the feel of the car resulting from the balance adjustment.
Weight transfer is the result of increasing speed, decelerating or cornering. If you speed up, brake or corner harder, you will transfer more weight.
For the driver controlling the car better, the driver need to be able to feel the weight transfer or something similar to it.
What Can The Driver Feel?
If accelerating of the car, certainly the driver can feel. But the most useful motions for the driver controlling the car better is a direct result of forces acting on the tyres.
If the the driver could feel from accelerating the car, it is the result from the linear forces of longitudinal acceleration, braking, and the lateral force of cornering. These are significant forces acting on the driver's body, and easily felt. When cornering, the linear force of cornering is felt on the driver's body as the lateral G-force, which builds up in entering the corner and that is gone in corner exit.
Due to the tyre slip angles building up in corner entry, the body of the car will rotate on the tyres slightly, creating a nose in attitude of the car that we could see when cornering.
This delicate rotation is an indication to the driver of the rate of turning through the corner. It's the rotation the driver can feel only under the right conditions:
1. If car rotates more than expected. Counter steering may be required.
2. If car rotates less than expected. Driver should push harder.
Pitch and roll occur because of the forces of acceleration, braking and cornering acting at the centre point of gravity of the car, causing weight transfer forward or back, or across the car.
If the centre of gravity is at ground level, there would be no weight transfer. But if centre of gravity is somewhere above the ground, there must be weight transfer. Thus, a lower car will have lower centre of gravity, which is always better. Thus, the lower car will always corner faster.