Coil springs support the weight of the vehicle and establish the ride height. As such they are the main components in lift and lowering kits for many vehicles. But performance coil springs can also improve handling, providing the stiffness required to reduce body roll and maintain traction at all four wheels. We have coil springs in a range of heights and spring rates, spring kits to replace air suspension systems, spacers to alter ride height, polyurethane isolators, and a large selection of spring mounts and hardware for both factory and custom installations.
Coil springs have 2 common specifications, free length, also called spring height, and spring rate, although lowering and lifting springs also specify the amount they will raise or lower the vehicle. Free length is the length of the spring when in its unloaded state. Spring rate is the measure of spring stiffness. It greatly affects handling and must be soft enough to let the suspension move over bumps, yet stiff enough to keep from bottoming or topping out. There are linear rate, sometimes called constant rate springs, progressive springs, also known as variable rate springs, and dual rate springs.
Spring rate is the amount of weight it takes to compress a spring one inch. If a 300 lb. load is applied to a 300 lb. per inch spring, the spring will compress one inch. In a linear rate spring, the rate is constant throughout the spring, and the coils are evenly spaced. Progressive springs have coils that are closer together at one end than the other. The coils that are more tightly wound provide a smooth ride, but when you step up the pace, they come together and the remaining coils compress at a higher rate, which prevents bottoming out, excessive body roll, front end dive, and acceleration squat. Dual rate springs are a form of progressive spring, but instead of a gradually changing rate, they instead have two distinct spring rates.
Our spring manufacturers carefully select spring rates for each application. Although lowering springs are a popular choice for lowering a vehicle, the downside is that most will only reduce ride height by a predetermined amount. If you want to fine tune the height, a set of adjustable coilovers is an alternative, but if you want to stay with coil springs for some applications we can offer you height adjustable springs. These springs come with threaded spring perches that will allow you to individually adjust each spring height, so you can get the perfect gap between the tire and fender at each wheel. This also means that you won't have to get a different lowering kit if you change your wheel and tire combination. Adjustable spring perches are also available separately for some vehicles.
If you have a Jeep, truck, or SUV and want to go up, we have coil springs that will raise ride height from 1” up to a towering 6” or more. However, unlike lowering kits which can often be used with OE shocks and the rest of the factory suspension, even a lift of only 1-2” may require longer shocks, and more parts and modifications are needed for higher lifts. We strongly recommend that you check out our selection of lift kits, which include components engineered to work together. If you want to raise your rig and retain your stock springs, we have spacers that can be used to level the front end or provide a lift all around. And if you need coil spring mounts for a custom installation, we have seats, pads, brackets, posts, buckets, and saddles, as well as hardware for secure spring attachment. |