Shocks, shock absorbers, struts, dampers, coilovers...what’s the difference? Suspension tuning can be difficult enough on its own, so getting our terminology right is a good first step before getting in too deep.
First up, don’t say “dampener” when talking about vehicle suspension. Damper, yes. Dampener, no. It’s not a big deal, but let’s not say that word.
Right, now that we’ve got that out of the way, let’s talk about dampers.
A damper converts kinetic energy (motion) into thermal energy (heat). We’re pushing a disc with holes in it through a tube full of oil to reduce vibrations and movement. We’ll get to all the different ways to do that some other time.
Without dampers, or with broken dampers, the springs on a car would cause it to bounce excessively after bumps. With dampers, energy from the springs compressing/extending is converted by the damper into heat and allows the chassis to settle.
“Shocks” and “shock absorbers” are dampers. A strut contains a damper, but is different in that the assembly is a structural part of the suspension. The strut body acts as a suspension link and has other functions beyond reducing vibrations and movement.
So what are coilovers? They’re often touted as the ultimate suspension upgrade, but all that word means is that the coils (springs) are over the damper. Struts are always a coilover. Shocks are sometimes a coilover. Most cars come with coilovers.
Coilover is a term that has taken on a slightly different meaning thanks to the aftermarket tuning world. Usually, we now talk about coilovers as any height adjustable suspension that packages a damper and spring together. This isn’t technically correct, but a lot of things aren’t in the aftermarket tuning world.
In part 2, we’ll talk about inverted struts, remote reservoirs, piggyback canisters, as well as the difference between monotube and twintube dampers.