Stage6 Clutch Shoe Springs - 2500 PURPLE (MAX RPM BRAND)Stage6 Clutch Springs for Torque Control Clutch. One of the easiest and most effective ways to hold off clutch engagement until the engine reaches higher rpm is to replace the springs and spring preload. The springs should match the engine's power band and performance. Rule of thumb: the harder the spring, the more clutch engagement point is delayed. These clutch springs are sold separately, available in 4 strengths. White Soft Orange Medium Red Race