The Volvo Parts, Accessories &
Performance Specialists Since 1963

Gas Shocks vs. Non Gas Shocks

2011-03-03 - IPD Staff

In England an automotive shock absorber is referred to as a “damper”. This is probably a better name as it more accurately describes what this part of your car does. As a car passes over the up hill side of a bump the springs in the suspension system are compressed. On the down hill side the springs extend. If that’s all there was to it you wouldn’t like it very much. The problem with this simple system is the springs will always over compress on the uphill side and over extend on the down hill side. The feeling in the car would be similar to a small boat in a rough sea. It would make you sick. A shock absorber dampens or slows down this motion and keeps the spring under control. It makes the ride much more comfortable and a lot safer.

A shock absorber works by forcing hydraulic oil through small holes as the shock moves. There are different holes for extension and compression. By adjusting this hole sizes and the valves that go with them, shock absorbers can be “tuned” to provide a particular result. Regular shocks offer good control with a focus on a comfortable ride. High performance shocks typically have tighter control and make the car ride a little bit stiffer. But they do offer much better control at higher speeds.

Many shock absorbers contain pressurized nitrogen gas in them as well as the hydraulic oil. If a shock has to react very rapidly to an up and down motion the hydraulic oil can start to foam. This foam causes the shock to lose some of its control. The purpose of the gas in the shock is to keep the oil under pressure so it is less likely to foam. This is the same reason a can of soda that has been shaken is still a liquid until you pop the top. The foam doesn’t start until the pressure is released.

At ipd we carry a variety of different shock absorbers. Each has particular advantages depending on your driving style and condition. Let us know what you want your car to do and we can probably suggest the best damper for your needs.