63-82 Composite Springs

To start off, lets first talk about factory steel leaf springs. There are two versions that were standard options for the C2 and C3 corvettes. The base model 9-leaf spring, and the Gymkhana 7-leaf spring. The base springs were rated at 180lbs while their 7-leaf counterpart were rated around 315-330 lbs. All steel leaf springs have rebound built in as they fight themselves when springing the car back up after hitting a bump. This directly affects your ride quality.

For composite springs, Van Steel can build a springs ranging from 300lbs for easy cruising to well over 400lbs for racing applications. Each composite spring is a low arch style that allows for factory ride height to around 1 1/2″ lower. A composite spring must be controlled by a quality shock to get the best handling or ride quality out of your Corvette. For this simple fact, the composite spring out handles and rides much better than a steel transverse leaf spring. The composite spring allows the shock to do the tuning for ride or handling and the spring is just holding the car up. The higher the spring rate, the more the spring can hold the car up with higher forces for cornering or hard launching.

So, how do you choose the spring needed for your Corvette chassis? There are a few factors we take into consideration. First is the weight of the car, mainly for cars that have been lightened or it’s a different model with a Corvette chassis swap. Second is horsepower, this is why most spring setups are called small block and big block. And lastly, how and where are you going to drive your car.

For weight, if it’s a lightened C2 Vette, the 300 and 330 lb springs are most common. This allows for shocks with light valving and will give you great ride quality along with minor handling gains over a 9-leaf steel spring. We typically pair these two springs with QA-1s standard non-adjustable shocks for excellent ride quality. If the car is heavier than original, whether it’s under a Chevy Nomad or you have a huge sound system in the back, a stiffer spring rate will help you get the car up to a proper ride height. These are more typically your 360lbs springs but can even be 400lbs if there is a lot of added weight over a factory Corvette.

Next up is your horsepower or projected horsepower rating. With more power and grip, the more the rear of the Vette wants to dip or squat under heavy throttle. This isn’t great for a lot of your rear end components on a IRS setup, plus it’s wasted motion. With high horsepower small blocks or even standard big blocks, anyone over 400hp typically should go with a 360 lb spring. The 360 spring gets just enough weight transfer to give proper grip to your tires, then the motion of your Corvette goes forward instead of down. Drag only and some road course applications run 400-500lb spring rates.

Then, how do you plan to drive your Corvette? Is it just a weekend cruiser just waiting for a parade to join in on, or do you like to carve up the mountain roads? Do you have the tendency to want to get a jump on that car next to you at a red light and just itching for the light to turn green? These are all things we ask to dial in your ideal composite spring.

On a final note, we also have shortened composite springs. These are for one thing and one thing only, tire clearance. Just a half inch off per side can be enough to give ample clearance from your wheel and tires. For those running 15″ wheels, we generally recommend going a full 1″ off per side, just note there can be some minor wear on the spring from the increased angle on the ride height adjustment bolts. For 16-17″ tires it’ll depend on how wide you go and your tire size, but generally 1/2″ off is enough. For 18″ and larger, you typically do not need a shortened composite, but depending on your width and backspacing, you could have some minor contact at full droop, but then it’ll clear once back on the ground.

For any further questions on composite springs, you can message us on Facebook, @vansteelcorvettes, give us a call at the shop 800-418-5397, or email us, salesteam@vansteel.com.