As promised, here is the next installment on car setup basics for Autocross. In previous articles we covered some of the fundamentals of tires, tire pressure and alignment. This article will cover sway bars and shocks.
The resistance of a car to leaning, or roll, while cornering is a primary factor in how a car behaves. There are two reasons for this: Roll affects how the tires touch the pavement and relative roll resistance determines how much weight transferred each corner of the car will carry in a corner. It is clear that a car’s body roll influences grip by tilting the tires on the pavement, but tires are also sensitive to how much vertical load is placed on them. More load equates to more grip, but the tire is also less efficient. Increasing the roll resistance of one axle of a car causes more load to be transferred at that axle, making the tires on that axle work less efficiently. It is this principle you work with by stiffening or softening the chassis. Sway bars and shocks are part of a car’s roll resistance. They are commonly adjustable and work in different ways to affect a car’s behavior.