A performance suspension is used to get better handling and driving out of a vehicle. Many times the upgrade will also raise up or lower the suspension which in turn will change the center of gravity. The suspension has many different parts and it is not necessary to upgrade the entire system, but just the components that need it. Some of the most common parts of the suspension include springs, shocks, struts, linkages, shock absorbers and the suspension support. Many car enthusiasts will use aftermarket or an import suspension to enhance the performance of the vehicle.
The main springs used in suspensions are coil springs or leaf springs. Leaf springs tend to be used with very heavy vehicles such as trucks, vans and SUVs. When the suspension is lowered or raised, the main part that is changed are the springs. A coil spring will expand or compress depending on the wheel motion. The leaf springs have several layers of metal that act as one unit. Air springs are the latest advancement, and these use cylinders of air that fit between the car body and the wheel. The air can be compressed and absorb the vibrations of the wheels. These springs are actually very old, as they were originally used on horse drawn buggies.
The shock absorbers function as a dampening structure. When the car is moving, the springs will change and release energy. Without shock absorbers, the springs will keep bouncing as the energy is transferred to the car body. The shock absorbers dampen the spring motion, providing a smoother ride. The science behind this is that the shocks will change the kinetic energy of bouncing into heat energy, which is then transferred to the hydraulics.
The struts are another type of dampening structure in the suspension. Besides functioning like a shock absorber, they also provide support to the suspension. A strut is actually a shock absorber that is found inside a spring. This is considered to be an important safety feature. When the struts become worn down the vehicle tends to lean more during turns. This in turn will affect the braking and cause the tires to have less grip on the road.
These bars provide additional support and stability to the vehicle. It is actually a metal rod that will join each side of the suspension together. The bar will stretch from axle to axle. When one wheel moves up and down, the bar will transfer that movement over to the other wheel, which levels out the ride and will eliminate most of the sway.
There are two main types of front suspension: a dependent system or an independent system. A dependent system will have a very rigid front axle that will connect directly to the front wheels. It will use shock absorbers and leaf springs. These are commonly found in trucks. The most common type of front suspension is the independent system in which the front wheels move independently. The most common strut in this suspension is the MacPherson strut.
The rear suspension is less complicated than the front suspension because there is no steering mechanism to deal with. There are dependent and independent options. For many years, American cars used dependent suspension because they were simpler to install. Today either is used, as any type of front suspension can be altered and used for the rear suspension.