Things to Know Before You Buy Coilovers
Coilovers are a funny thing. With a seemingly new brand cropping up every week it can be hard to figure out what is quality and what is garbage. Today we’re going to look at some of the things you need to know to arm yourself with the knowledge that will help you make the right decision. Hopefully at the end you learn something new.
Application
What you need really depends on your intended use. Do you race or is your car a dual purpose street/track car? Do you just drive on the street and want the adjustability or wow factor? Do the roads in the area you drive have good road surface, or does it feel like they were carpet bombed and never repaved? Answering these questions affect your setup and choices. Once you get into dedicated racing parts the rabbit hole gets deep and prices can easily sky rocket into the 5 figure range. Everything depends on what you are tuning the car for and there are few absolutes.
PRO TIP: If you’re not running in a professional series you probably don’t need the most expensive stuff. Save your money and get something you upgrade later on. This leads us to…
>>Join the conversation about Things to Know Before You Buy Coilovers right here in the S2Ki Forum!
Adjustability: One way or Two way?
Extending on the concept of application is the question of adjustability. All coilovers allow you to adjust spring preload, and sometimes ride height, but what we are talking about is adjustable damping. A shock absorber has two ranges of motion: Compression and Rebound. Coilovers that are one way adjustable typically adjust the rebound side of the shock. Think about a car going through a left hand corner - the right side squats down and the left side rolls up. That rolling up of the left side is the rebound, and adjusting this is where most of the benefit occurs. Two way adjustable coilovers allow adjustment of damping in both directions. If you’re new to performance driving then you want to focus on just playing with rebound as it offers the most noticeable increase in performance.
PRO TIP: Fine tuning rebound and compression is a science. You have to test a lot to get it right so spend plenty of time at the track trying various settings making note of lap times as you do so. If you can find someone who has knowledge of your specific car and brand of coilovers, and is willing to help you it will greatly speed up the learning curve.
>>Join the conversation about Things to Know Before You Buy Coilovers right here in the S2Ki Forum!
Ride Height
For a tire to be effective it needs range of motion and wheel travel. Slamming your car to the ground is the fastest way to kill performance. You might think it looks cool until a guy in a stock Honda Civic blows your doors off at the race track. This isn’t to say there aren’t gains in lowering the center of gravity, however, doing it in excess is the wrong way. So how low is too low? Any ride height that bottoms out the shock or has your tire rubbing in a fender is too low. Bottoming out in the middle of a corner causes a rapid loss of traction on the end of the car that bottoms out first. At the front this means sudden understeer. On the rear it means sudden over steer. Really not ideal conditions at high speed.
PRO TIP: Race cars and road cars are not equal. Any setup that has to do two things (i.e. street & track) is going to have to compromise on one. You need travel to absorb things like curbs at the race track. Having a car too low can damage underbody components or even the bodywork itself!
>>Join the conversation about Things to Know Before You Buy Coilovers right here in the S2Ki Forum!
Spring rate
Spring rate depends on application! I have driven cars with 1000lb/in springs on the road that were more comfortable than 350lb/in springs. So how can a stiffer spring be more comfortable and take bumps better? The shocks on the 1000lb/in spring were custom valved for those rates with specially designed internals with ride height and shock travel perfectly matched. Now is where you start to scratch your head. This is why everything depends on application. In general people talk about spring rates and coilovers like we all have the same setup. This isn’t the case as you begin to understand how each component works with the others to form one complete system. Generally speaking a stiffer spring will ride harder than a softer spring. In endurance racing we typically see softer spring rates than sprint racing. Why? Because we need to make the tires last. Stiffer springs put more energy into the tire and heat it up quicker!
PRO TIP: The more you know the less you know. People assume stiffer means more performance. This is another myth as it all depends on what you need the tires to do, how long you need them to last and what type of surfaces you drive on.
>>Join the conversation about Things to Know Before You Buy Coilovers right here in the S2Ki Forum!
Buy quality and ask for a dyno chart
I’d like to assume most people who read this are serious about performance, so I want to address the topic of quality. If you have made the decision to fork over $1000 for a set of coilovers I would really recommend saving a little longer until you can buy something in the range of $1500-$2000. Sometimes you can get lucky and find a used setup that cost someone double what you’re paying. Each car has the known “super tuners” who offer stuff a step down from the all out setup of a company like PENSKE. Talk to the experts and tell them your intended use. Don’t just call one person either! Call several and see what each of them says, then compare their opinions. Avoid anyone who won’t give you a shock dyno chart of the exact set you are putting on your car.
PRO TIP: Cheap coilovers tend to have a bad feature called cross talk. When you adjust rebound you are also adjusting compression or vice versa. This is a bad thing as you want them to be independent of each other to maximize control of the wheel.
>>Join the conversation about Things to Know Before You Buy Coilovers right here in the S2Ki Forum!
That's all folks
So there you have it. A short article about some things you might have not known about coilovers and suspension in general. I’m currently working on an article that is shock specific and a little more in depth, as well as an article about how to read shock dynos graphs and what they mean. Hopefully this helped you learn more about a common topic in the car community, and informed you a little more than you were prior to reading. See you next time!
>>Join the conversation about Things to Know Before You Buy Coilovers right here in the S2Ki Forum!