The heart of a suspension system is the springs. Springs perform five critical jobs. First, they keep the chassis and suspension from bottoming out over bumps. Second, they control the tires over bumps. Third, they control body roll during cornering, chassis squat during acceleration, and chassis dive under braking. Fourth, the springs determine how the load on the tires shifts during braking, cornering, and acceleration. This makes them a pivotal component in establishing the neutral handling balance of the car. And finally, the springs are the major factor in establishing the ride height (ground clearance) of the chassis. The series of compromises needed to create the ideal setup for a given car and performance application require experience, engineering, and testing.
Sport springs should lower the car which also lowers the center of gravity and improves handling performance. But if the springs are not stiff enough at the lower ground clearance, the chassis or suspension will bottom, causing damage to the chassis or suspension. If the springs are too stiff, the ride is horrible and tire contact patch control over bumps deteriorates. For a competition situation, ride comfort is not an issue, but controlling the tire contact patch over bumps is a major concern. Bumpy surfaces require softer springs than smooth surfaces. This compromise is critical.
