- 04 Oct 09, 16:11#160236When F1 drivers talk about oversteer or understeer balance, they are often talking about the car's center of pressure. This is the combination of the standing center of gravity of the car and the aerodynamic center of pressure on the car.
The center of of aerodynamic pressure on the car can be moved forwards and backwards at in order to induce understeer or oversteer by adjusting things like wing angles but every aerodynamic component on the car plays a role. A basic example would be something like a driver wanting less understeer and therefore adjusts the front wing to create more downforce or the rear wing to create less downforce, moving the aerodynamic center of pressure forwards.
The standing center of gravity can also be adjusted at a setup level by moving ballast around within the car. The center of gravity as the car is motion can be adjusted by the driver using the brake and accelerator and this is largely how drivers compensate for either oversteer or understeer during a race. Braking throws more weight onto the front of the car and gives oversteer, accelerating throws more weight on to the rear of the car and generates understeer. Of course, loosing grip under braking by locking the wheels compensates for this by reducing the amount of grip the front wheels have in relation to the rear wheels. Under these conditions, the car would understeer. Accelerating too hard causes wheelspin which reduces the amount of grip the rear wheels have in relation to the fronts, causing oversteer.
Suspension setup also has a bearing on whether or not the car will oversteer or understeer and in racing series where downforce doesn't play as great a role, this is how the handling characteristics of the car are largely defined. Stiff suspension settings mean that the mass of the car remains more stable during cornering and means that the tires are pressed into the road more evenly, thus generating more overall grip. However, stiff suspension settings mean that the tires are more likely to skip up off the road when responding to bumps and this means grip is lost. High bump rares must be met with appropriate rebound rates in order to ensure that when the wheel skips up off the surface, it returns back to it again as quickly and finally as possible. Setting the suspension or roll bars stiffer at the front of the car than the rear will generate understeer as the front wheels loose contact with the ground more frequently than the rears. Parameters such as toe in/out, and camber also affect the way the tires interact with the road and can enable the car to be setup to oversteer/understeer more gradually or to further ensure the mass of the car stays stable and over the wheels during cornering.
