What to Consider When Buying Suspension

This article was written by Coilovers.com Owner and Principal, Lou Tortola.

Buying suspension is one of the biggest aftermarket purchases you will make for your car. Lowering springs, a full coilover kit or something else, the right setup changes how the car corners, brakes and handles rough pavement. You want to get it right the first time. Fixing a bad suspension purchase often costs more than buying the right kit up front.

If the list of parts feels like a lot, this is the guide to buying suspension we walk customers through on the phone. Here is what each part does, which kit type fits which kind of driving, and how to avoid an expensive mistake.

The Main Suspension Parts, Explained

Springs

The spring is the energy-storing part of the suspension. It supports the car's weight, absorbs road impacts and resists body roll through corners. Spring rate, measured in pounds per inch or kilograms per millimeter, is one of the most important tuning choices in any setup. Get the rate badly wrong for your car and driving, and the rest of the setup has to fight it.

Dampers (Shocks or Struts)

The damper controls how the spring moves through its stroke. Without damping, a spring would keep bouncing after every bump. The damper turns that motion into heat through hydraulic resistance and helps keep the tire on the pavement.

Monotube designs shed heat well and suit hard use. Twin-tube designs give more travel for their length, and with street valving they often ride softly. Both are valid. How the kit is engineered matters more than the tube count. Our monotube vs twin tube guide covers the trade-offs.

Coilovers

A coilover suspension combines the spring and damper into one assembly at each corner. It mounts on a threaded shock body, and a locking collar holds your ride height setting. Adjustable damping is common, and that control is something a factory setup cannot match.

A coilover kit is the most common performance suspension upgrade for enthusiasts who want real control over how the car handles. One note on unsprung weight, the mass the springs do not carry. A coilover does not cut it automatically. That mass lives mostly in the wheel, tire, hub and brakes.

Sway Bars

Sway bars, also called anti-roll bars, connect the left and right sides of the suspension and resist body roll in corners. Stiffer bars reduce roll and shift the car's cornering balance. They pair well with a proper coilover kit and are often one of the best handling upgrades for the money.

Control Arms

Control arms connect the wheels to the chassis. Each arm affects caster, camber or toe. Upgraded arms are often used to restore or fine-tune geometry after a ride height change. On lowered cars, adjustable arms are often needed to bring the geometry back to spec. See our guide to performance control arms for more.

Tie Rods

Tie rods connect the steering rack to each front wheel and carry your steering input to the tires. They do not usually change with a suspension upgrade. Their length and angle still matter on dropped cars, and they get adjusted during every alignment.

Tip 1: Pick the Type of Suspension That Fits How You Drive

There are three main types of aftermarket suspension: lowering springs, coilovers and air suspension.

Lowering Springs

If you want to keep most of the factory suspension and just drop the ride height, lowering springs are the low-cost starting point. They replace the factory springs with shorter, usually stiffer springs and keep the factory dampers. Install is straightforward. Just remember that the factory dampers were never valved for the new springs.

On cars with factory electronic damping, lowering springs let you keep that system working. So can BC Racing's ASP Series, an adjustable spring perch kit that keeps the factory electronic dampers on selected applications.

Coilover Kits

This is the most common choice for people who want the car to handle better and sit lower, with real adjustment. Aftermarket coilovers replace the factory spring and damper at each corner with one matched, adjustable assembly. A coilover kit gives you ride height adjustment, damping control on most kits, and a matched spring and damper. Brands like BC Racing, KW, Fortune Auto, TEIN, Bilstein, Öhlins and Feal all build them. For serious street and track use, this is where most people end up.

Air Suspension

Air suspension replaces the springs with air bags and adds a management system to control pressure. The big benefit is that you can raise or drop the car at the push of a button. Air suspension often costs more than many coilover kits, and it needs ongoing maintenance the other two do not. It makes sense for show cars and stance builds. For pure handling, a proper coilover kit is usually the better choice.

Tip 2: Know What You Get at Each Price Level

Once you have picked the suspension type, start looking at brands and prices. You do not want to underpay or overpay. You do not want a kit that cannot keep up with how you drive. You also do not want a full race kit when a street setup would serve you well.

A more useful way to sort kits is by how much adjustment you get. Our guide to adjustable coilovers explains each level. Price tends to follow adjustability, engineering and build method.

BC Racing offers its whole range of series at a good price for what you get. On BC Racing kits, Swift Springs SPEC-R springs are an upgrade option on most fitments. They ship standard on HM and ZR Series kits on most fitments.

Tip 3: Do the Research Before Buying Suspension

Read reviews, watch install videos and look up write-ups on your exact chassis. Are suspension kits worth it? A good one stays with the car for years, so the research up front pays off. Look for owner reports on your exact year, make, model and trim, not generic brand testimonials.

Pay attention to what owners say about ride quality over time, not just on day one. Check how the kit handles roads like yours. Cold weather, salt-belt corrosion and heat on track days all matter, depending on where you live and how you drive.

Tip 4: Work With a Dealer That Actually Helps

This is the step most buyers skip. Anyone can take an order. Not every seller stays involved once the box ships, and that support is what you need when a question comes up mid-install. We cover this in our look at buying coilovers online.

We built Coilovers.com on one principle. Every customer gets as much attention as they need, for as long as they need it. We answer our phones during business hours. We reply to emails. We stay with you until the kit is on the car and you are happy with how it drives.

Plan for the Install, Alignment and Lead Time

When buying suspension, plan for installation if you are not doing it yourself. Plan for an alignment after the install, which every kit needs. Plan for possible geometry parts, such as camber arms on lowered cars. The full cost is the kit plus the coilover installation cost, the alignment and any extra parts your setup needs.

Plan for coilover lead time too. Some kits ship fast. Others are built to order, like every Fortune Auto kit, and that takes longer. Tell the dealer your timeline before you commit so they can match you to a kit that arrives in your window.

Frequently Asked Questions

Keep reading: Our guides to reading kit fitment and drivetrain and fitment.