By Any modification of your car’s suspension setup is a serious decision. Changing stock suspension can change the way your car behaves. One bolt-in solution is an aftermarket set of adjustable coilovers to replace a standard shock absorber-and-spring system. This more advanced suspension system allows for adjustable ride height and dampening as well as other fine tuning; this allows for decreases in body roll, better ride, and smoother transitions in corners.
The first part of selecting a set of coilovers is to figure out how and where you’ll be driving. Are you looking for a system for street use, or one for high-performance driving experiences and track days? Time attack, drifting, and drag racing all benefit from different components. Manufacturers may offer unique systems for several of the areas listed, or they may have a single offering targeted at one of the driving modes mentioned.
As always, when you consider making any changes to your suspension, the factor you need to consider first is the tires, as they are the vehicle’s only direct link to the road. In fact, the coilover kit you select should be one tuned to the type of tires that you’ll be using. For example, street coilovers take best advantage of ultra-high performance summer tires. Performance coilover systems designed for track use are more aggressive to pair with slicks or DOT-R tires, and tend to ride tighter than most people will be comfortable with on the street.
For track days, a set of moderately-priced coilovers, combined with larger diameter sway bars with adjustable links are a great starting point. As you learn the characteristics of the car over laps and laps of track driving you can begin to make adjustments – one at a time – to optimize the set-up to your car, tires, and driving style.
Why Coilovers are an improvement Over Springs and Shocks
The separate springs and shocks or struts with which your vehicle was built are a compromise between several factors, primarily responsiveness and ride comfort. The more a car is intended for luxury, the more the springs and dampers are tuned toward ride comfort. On a vehicle with a performance suspension package, the opposite is true.
In all but a few cases where full-on track packages are an available OEM option, stock suspension components aren’t up to circuit driving or even canyon carving. While a simple upgrade of replacement struts and lowering springs offer a significant upgrade from stock, and in many cases are a good starting point for a daily driver starting off in performance driving, they lack some of the important features inherent in an aftermarket coilover setup.
Coilover Springs
But before we get to that let’s consider the individual elements of a coilover suspension. First, are the springs. On a coilover system, these are helically wound from a high tensile steel alloy. The steel needs to be able to provide consistent and reliable characteristics like free length and spring rate for years of driving without yielding, which is a key element in how much weight is transferred to each tire during cornering. It’s important to source your coil spring from a well-known brand, like Tein, Eibach, Koni, or Bilstein, that has a history in motorsports as you’ll be assured that the springs you buy will provide extended use and consistent performance. These companies will also provide you with solid technical information to help you select the proper spring, not just in rate, but in size and configuration that’s best for your application.
Almost all coilover systems offer an adjustable spring perch. While it’s true that the preload of these can be used for height adjustment, they can also be used to shift the weight on each wheel. This allows you to equalize the weight on the wheels as much as possible for more consistent handling throughout turns. This is called corner balancing. You can do this at home with a bathroom scale and a lever, buy your own dedicated scales, or take it to a professional race shop, as a standard alignment shop will likely not offer this service.
Coilover Dampers
The initial role of a damper was to control the release of energy by the spring after striking a bump in the road or from loading in a turn. They’ve become more complex, particularly in coilover configurations, as they are one of the most important aspects of suspension tuning. And with those developments has come a wide range of adjustability so that the driver and team can develop an optimum set-up for every track and condition.
There are several levels of adjustability. Be aware that with every increase in the ability to tune the shock comes an accompanying increase in price. In this case, think long term. If you are committed to becoming an expert track driver, then investing a sophisticated system to start with saves you from the expense of having to buy a more advanced system in a few years.
On the other hand, if you’re an occasional track day driver with no long term plans, a less adjustable system will not only save you some money but also reduce the complexity out your set-up so you can concentrate on your driving (and not be overwhelmed with adjustability).
Single-way adjustable dampers allow you to alter the compression characteristic alone or a combination of compression and rebound. Two-way adjustable dampers allow for a rebound adjustment as well as compression. Four-way dampers offer both high-speed and low-speed settings for compression, along with high-speed and low-speed setting for rebound. So what does that actually mean?
- Low-speed compression controls the compression speed when the suspension compresses slowly, such as in corner entry and exit.
- High-speed compression damping controls the compression speed when the suspension compresses very quickly, affecting the stability of the car during fast changes in driver input.
- Low-speed rebound damping controls how quickly the suspension can extend after being compressed.
- High-speed rebound damping controls the speed of extension following a deep compression and effects the suspensions ability to recover following multiple impacts.
One final note: once you replace your OEM springs and dampers, the wheels and tires will be in a different position in terms of the suspension geometry (camber, caster, toe, etc). It’s important to realign the car after a changeover.
There’s enough information on this page to make you dangerous. When you get into three-way and four-way adjustable settings start with the settings recommended by the damper manufacturer based on your vehicle, other suspension changes, and the tire you’re running as a starting point. Then, begin to play with the adjustments to understand what each does separately (never make two adjustments at the same time unless you’re a professional). Use an open track day to play with the adjustments, taking each one in turn and trying a few laps at the maximum and minimum settings. With that knowledge you can start to apply smaller adjustments to improve handling and lap times.
Motoroso offers a wide variety of high-quality coilover springs, coilover dampers, and full coilover suspension kits to provide you one the widest online selections suspension components for your car, truck, or SUV. It may take a while to decide, but always keep in mind that the “best coilovers” are the ones that work for your particular driving plans.
