The Detroit Speed rear coilover conversion kit is a direct bolt-on assembly that completely replaces the OEM rear strut assembly. The kit uses a Detroit Speed/JRI high-performance aluminum shock with 'Detroit Tuned' valving. The kit allows ride height adjustment and easier rear spring changes and lowers the car approximately 1.5" from stock at the nominal design position.Spring Rate: 450lbs/inSpring Free Length: 8in