Coilovers

What Are Coilovers? | Tuning 101

The suspension is one of the most important systems of your car and coilovers are some of the most advanced components. For starters, the suspension is responsible for keeping the car “glued” to the road surface while simultaneously eliminating its negative impact. In other words, the suspension is involved in a constant struggle between handling and ride quality. By definition, the vehicle suspension encompasses everything from tires and tire air, over springs and shock absorbers, to linkages that connect them to the body or frame of a vehicle. But to really understand what coilovers do and why you might want some, here’s an article covering just that: what are coilovers, what are the main advantages and drawbacks and what makes them different from other types of suspensions.

Skunk2 Pro S Coilovers for Acura RSX 05-06
Skunk2 Pro S Coilovers for Acura RSX 05-06

What Are Coilovers?

So, what are coilovers then, and where do they come in? Coilovers are an advanced type of suspension setup consisting of both a shock absorber (damper) and a coil spring. More precisely, they consist of a coil spring encircling the shock absorber hence their name – coil over shock absorber.

Once almost exclusively limited to racing cars, coilovers have ultimately found their way to the conventional car market and are now a highly coveted commodity among tuners and other car enthusiasts. That’s because coilovers allow for several adjustments to the car.

One of the most common uses of coilovers is to lower the height of a vehicle including its center of gravity. However, that’s just the tip of the iceberg.

As with any type of suspension or suspension components, coilovers have pros and cons of their own. The advantages and disadvantages of employing a coilover-type suspension are listed below.

Ksport Kontrol Pro Coilover Kit for Scion TC 2005-2010
Ksport Kontrol Pro Coilover Kit for Scion TC 05-10

Benefits of Coilovers

There are numerous benefits of using coilovers in both track-focused and off-road vehicles.

Adjustability

Only one of coilovers’ biggest advantages over other suspension setups, but arguably its most focal point as well. Not only can you lower or raise your car in the simplest of manners, but, depending on the model, you may also adjust the rebound, handling, and ride quality as well.

Better handling

As mentioned above, coilovers’ adjustability can greatly improve your ride’s handling. More so than a set of performance tires, for instance.

Perfect balance

Most coilover setups are perfectly balanced from the get-go. More even weight distribution means that the tires have a maximum grip around the corner which also improves safety. Similarly, accelerating and braking don’t transition as much weight to the back and front respectively.

Reduced body roll

With coilover adjusted for stiffness, the overall roll of your vehicle should be greatly reduced. Furthermore, many coilover suspension kits come with camber adjustment slots helping to keep the suspension geometry intact.

Simplicity

The simplicity of use is another important factor of coilover suspension setups. Adjusting a coilover is often as easy as turning a few screws.

Drawbacks of Coilovers

Of course, like any setup out there, coilovers come with issues of their own.

Higher cost

When compared to other suspension setups, coilovers are definitely more expensive. High-quality aftermarket coilover sets from reputable manufacturers will cost you upwards of $1,000; going well over $3,000 for most complex setups.

Cheaper coilovers

You can quit easily find cheaper or imitation coilover models are readily available on the market but don’t even think of going that way for a multitude of reasons. Most of the aforementioned advantages of a coilover setup can instantly turn into your worst nightmare in a setup of sub-par quality. Poor quality or even badly optimized coilovers can lead to stiff ride, poor handling, the possibility of failures, lack of travel space, etc. If you don’t have the budget, you might be better off buying a cheaper set of lowering coil springs instead or simply leave your car as-is. A stock suspension, no matter how soft it is, is often better than a cheap set of eBay coilovers.

The Difference Between Shocks, Coilovers, and Struts

These 3 terms are sometimes thrown around a bit and may lead to a bit of confusion. Let’s try to define each one and see how they differ.

Shocks

A shock is the simplest suspension component and was more largely used on older vehicles, especially in the rear with non-independent suspensions. With this type of suspension, the coil is placed beside the shock and not over it. This specific setup is simpler, cheaper, and a lot easier to replace. However, it’s also the least efficient in terms of handling power.

Struts

The most common example of struts is with MacPherson struts. This type of suspension also features the coil spring over the shock but serves as a major structural component of the suspension. In most cases, the strut is also used in place of the upper control arm and to steer the wheels from left to right.

Coilovers

Coilovers basically combines the abilities of a strut with the damping of a shock and are installed as a single unit. They’re also usually adjustable in height and rebound rate.

Lowering Springs vs Adjustable Coilovers

Understanding that one of the main advantages of employing a coilover-based suspension is the ability to lower your ride is the main reason behind the lowering springs vs coilovers dilemma. Lowering springs, as their name suggests, will also lower your ride as that’s their main purpose.

Unlike coilovers, however, lowering springs have pre-defined spring rates and ride height. Even non-adjustable, entry-level coilovers (partially threaded coilovers) come with partially-adjustable height but you can’t adjust their stiffness, compression, and rebound rates.

Fully adjustable coilovers, on the other hand, offer all of the aforementioned. In that sense, adjustable coilovers are definitely a way to go although lowering springs are much more affordable.

4 way Adjustable Coilovers Ferrari 458 Italia 10-14
Coilovers come in all shapes and prices. Here’s a $6K kit for Ferrari 458 Italia

Different Types of Adjustable Coilovers

While even non-adjustable coilovers offer some adjustability options, things get more interesting with fully adjustable coilovers which allow more liberty in fully customizing a suspension. Here are some of the main examples of adjustable coilovers.

  • Height-adjustable – all coilovers are height-adjustable to a lesser or greater extent but let’s take the partially threaded coilovers as an entry-level example. They feature a spring perch and a locking collar which allows for height adjustment by turning them counter-clockwise and clockwise respectively.
  • 1-way adjustable – essentially, this means that, aside from height, you can also adjust rebound and compression as well. This should work for most people as more advanced options are usually only used by racing teams.
  • 2-way adjustable – this would allow adjusting rebound and compression simultaneously and independently, for instance.
  • 3-way adjustable – this is where you can adjust rebound, high-speed, and low-speed compression.
  • 4-way adjustable – the ultimate level of adjustable coilovers. Allows adjusting low and high-speed rebound, as well as low and high-speed compression adjustment.

Don’t be confused if you see a “32-way adjustable coilover” sticker somewhere, for instance. In essence, they’re probably 1-way adjustable, but with a 32 clicks adjustment range. It’s a misuse of the adjustability term and can be somewhat misleading.

Bilstein B16 RideControl Kit
Bilstein B16 RideControl Kit
Bilstein B1 (iRC) - Active Suspension Control Module
Bilstein B1 – Suspension Control Module

On the other hand, it’s even now possible to find coilovers kits that can be adjusted in real-time using an app on your phone.  Blistein B16 RideControl coilover kits, for example, can be paired with the Bilstein iRC Smartphone Controller for the ultimate ride-height adjustment

How to Adjust Coilovers

Adjusting coilovers really depends on the type of coilover you’ve got. Some are easier, while others require a bit more work to adjust. Then again, everything beyond 1-way adjustable models can be extremely complex to set correctly and should only be done by professionals.

Mechanic adjusting coilovers

Adjusting height

Most coilover requires only two spanner wrenches to adjust the height; one on the spring perch turning counter-clockwise and one on the locking collar below it, turning clockwise. Once they’ve been loosened, it’s easy to adjust the ride height by simply turning the locking collar by hand until you reach the desired position and then turning the spring perch with a spanner – clockwise to lower the car and counter-clockwise to raise it. Once the desired height has been reached, simply return the locking collar to the spring perch by hand and tighten them up with spanners.

The fully threaded setup also allows for pre-load adjustment. To do so, you’ll have to loosen both the spring perch and locking perch until the spring is completely unloaded. Then slide them both up with your hands until they can’t be moved any further. Finally, use a spanner to turn the upper spring perch counter-clockwise until it separates from the locking perch. The separation will be your pre-load. In the end, you only need to lock them both together again by using spanners.

Adjusting the rebound and compression rate

If your car is equipped with 2, 3, or 4-way adjustable coilovers, you’ll also be able to adjust the rebound and compression rate to your liking. Doing so is quite easy as most coilovers will have knobs on the side or on the top of the shock absorber letting you increase or reduces the rates. However, what’s can get quite complicated is knowing how to set them.

Depending on the type of racing you are doing, the setup may be completely different. For example, a suspension setup for drag racing has nothing to do with a drift setup. Finding the right one for you will require a lot of on and off-track testing. Your best bet here is to select base settings, do a test run, change the setting, test it again, look at the time result, and repeat.

There’s simply no easy way to do it aside from testing it and seeing what works best with your driving style.

Last Words

Coilovers are essential to any individual willing to push his/her car’s performance to the limit. They’re arguably the best option on the market thanks to their high adjustability ratings and ease of use. Ever since they migrated from the tracks into our daily lives, coilovers have been highly coveted by tuners and performance enthusiasts alike. They provide both quite a significant aesthetic and performance boost. Installing coilovers can be conducted in the safety of your garage and is not that complicated at all. Tuning a high-end coilover set, on the other hand, is a task better left to a professional. You’ll see that finding the right balance between ride height, spring stiffness, and handling can be daunting. Even more so when you add camber adjustment to the equation.

Find a set of performance coilovers for your car here.

About Nikola Potrebić

Avatar
Nikola strives to preserve the untold stories of the '70s and '80s special-edition and limited-run models from the U.S. market. He also has a penchant for Saabs and Volvos, and wouldn't mind seeing more contemporary cars with a manual gearbox.

Leave a Reply

Your email address will not be published. Required fields are marked *