Learn About Handling from the Driver's Point of View
The Driver’s Experience: The driver has set a direction or heading for the car with an initial movement of the steering wheel. If the car turns (or rotates) less than the driver expects, we say the car is understeering. If the car turns more than the driver expects, then we say that the car is oversteering. The driver anticipates the onset of oversteer or understeer by adjusting steering, brake and throttle so as to influence the weight transfers and rotation of the car on corner entry. Effectively, to combat understeer, the driver will try to rotate the car a little more on corner entry, so as to have less steering angle by the corner apex. To combat oversteer, the driver will try to drive the flattest possible trajectory for the corner, minimise steering angle and wait as required before accelerating off the turn.
Slip Angles at the Tyres
The slip angles at the tyres are key to understanding handling. In fact, with no slip angles, the car would be uncontrollable at speeds anything much above 20 kph. At the centre of the driver feedback process is the tyre slip angles and the resulting Body Slip Angle. In our training course, "Every Racer's Guide to Suspension Tuning" we discuss exactly how the change in Body Slip Angle leads to change in Lateral G that the driver can feel. Lateral G sensing, the driver's most finely sensed feed back mechanism, used to sense understeer and oversteer, is coming from the rate of change of Body Slip Angle - the Body Slip Rate. Without the Body Slip Rate and the Tyre Slip Angles, we could not control the car.