If you have a Dinan Coil-Over kit and ever thought that your suspension could be stiffer for increased road feel and performance than this is the solution for you. This pair of front springs are 19% stiffer than the ones included in the base Dinan Coil-Over package and the spring rates are optimized for track use with R-compound tires. The end result is a suspension system that hugs the road letting you feel the course in front of you with significantly less squat under acceleration and dive under braking.