Choosing Sports Spring For Your Car

Lowering Your Car Properly Using Sports Springs


Rate vs. Load vs. Sag

It's all too easy to get lost in suspension lingo. However, when it comes to springs, there are a few terms that you should get familiar with and understand.

- Spring rates are generally rated in pounds per inch (lb/in), which represents the amount of force required to compress the coil spring by 1 inch. For example, a 900 lb/in spring will compress 1 inch under a load of 900 pounds. This is not the same thing as pounds per square inch (psi), which is a measure of pressure.

- Spring load is the amount of weight that a coil spring can support at any given compressed height. More simply put, if a 10-inch-tall spring at free height with a 200 lb/in rate were compressed to a height of 6 inches, it would be supporting 800 pounds at that height.

- Spring sag happens over time and will eventually drop a car's ride height even lower. While this won't affect its spring rate, it can cause other problems, such as ground clearance, causing the tires to rub or the chassis to compress onto the bumpstops.

Be sure to check your alignment any time you alter the ride height. While lowering your street machine will vastly improve the center of gravity for better handling, it can also increase negative camber--the inward tilt of the top of the tire (as shown above). This causes excessive wear on both the tire and suspension components.

Hope this info will help you when considering to lower your car.