Performance springs (SP080) will drop your S550 Mustang 1.2-inches, and feature a fine-tuned spring rate (170lb front, 740lb rear) to give you a smooth ride.
Drag springs (SP086) will drop your S550 Mustang 1.2-inches and feature fine-tuned spring rates to give you improved launches. The front springs are linear with a 250lb/inch rate. The rear spring is dual-rate with a working rate of 980 lb/inch.
Handling springs (SP083) will drop your S550 Mustang 1.2-inches and feature a fine-tuned spring rate to give you great handling. The 150 lb/inch front linear spring rates offer plenty of support, keeping the body flat and level in the corners. The 800 lb/inch rear dual-rate spring decreases body roll and gives you a lower center of gravity for increased driver control in aggressive cornering situations.