Before we get into the pros and cons of coilover suspension, let us look at the limitations of the cars standard suspension.
1. Coilover Suspension – Springs.
Standard car suspension uses progressive springs. Progressive springs are soft in their first part of travel before jumping to their the full spring rate after they are compressed a certain amount.
Why are progressive springs progressive?
Ride comfort. The initial soft bit of travel in the standard springs allows the suspension to absorb bumps in the road and pass less shock into the cabin.
Why is this bad?
Instability. For the normal driver this bit of progressiveness in the spring travel is not a bad thing.
For advanced drivers this soft piece of travel in the spring can cause major issues.
Fast direction changes. If take a while for the suspension to load up with progressive springs. If you turn right and then turn left in quick succession the suspension will still be loading up on the left side while you start the following left turn. This exaggerates movement in the suspension because not only does the suspension have to go through the initial part of soft spring travel, the suspension also has to recover from the initial movement in the suspension to the left.
The situation can lead to huge instability depending on how progressive the springs are. The longer the soft bit of travel in the spring the more pronounced this instability will be.
How do coilovers solve this problem?
High quality coilovers can be run with springs that do not use progressive springs. This means the suspension loads up immediately meaning the suspension keeps up with movements of the car’s body.
Ride comfort can become worse. More shocks from bumps can be passed into the cabin. However high quality dampers can largely overcome this problem.
2. Coilover Suspension – Shock Absorbers (correctly called dampers)
Standard dampers are not adjustable. This means regardless of where you live, regardless of how good or bad the roads ae that you drive on, regardless of how use use your car (track/road) the suspension is the same. In other words the suspension is a massive compromise.
Coilover suspension comes with adjustable dampers. This means you can make the damping have more control of body or less depending on your driving and the roads you are driving on.
In a sentence, you can customise your suspension depending on the conditions, no compromise.
If you are an advanced driver and you want your suspension to behave differently according to road conditions and the way you are driving, coilover suspension gives you everything you need and this is why you need coilover suspension.
Coilover Suspension – Which one is right for you?
Like everything, you get what you pay for.
So what is the difference between cheap coilovers and expensive coilovers?
The main difference is in the valving and the adjustments available.
Lower cost dampers will adjust bound and rebound together, whereas the more pukka coilover suspension setup allow the driver to adjust bump and rebound independently as well as adjusting for speed.
So not only can you adjust for bump and rebound independently you can also adjust high-speed and low-speed bump and rebound independently. In layman’s terms you can adjust the suspension’s behaviour for bumps and cornering forces separately,
This gives a simply massive range of adjustability but this adjustability comes at a price.
And in between these two extremes you have dampers which contain valves which behave differently according to the speed of the movement. The damper behaves differently between high and low-speed movement but this factor is not adjustable by the user.
Springs are a leveller.
Coilover suspension usually use 2.25 inch inner diameter springs meaning you can use the highest quality springs on the lowest quality dampers, springs are completely interchangeable.
Quality coilovers start at around 600GBP from UK based manufacturers such as GAZ & Spax.
These companies are heavily involved in motorsport and are well-respected in the UK.
From here we move to manufacturers from Germany and Holland with Koni, H&R and Eibach.
Then we go on to names like Moton, Nitron, Penske & Ohlins which offer the full banana when it comes to adjustability.
The high-end manufacturers tend not to offer off the shelf solutions and are degined for user who have the ability to fabricate their own mounts. Users like race car manufacturers.
So there you have it. Why you should buy coilover suspension and what to kit to buy.