Eibach ERS 4in Length x 2.5in ID Coil-Over Spring (0400.250.XXXX) Spring Rate:400 lbs/in The undertray is made from

The undertray is made from high-grade 2mm 5251 aluminum

while in the case of higher damper speeds

2003 BMW 745Li

Key features include: 30mm diameter high-strength steel construction for increased stiffness and durability

Eibach ERS 4in Length x 2.5in ID Coil-Over Spring (0400.250.XXXX) Spring Rate:400 lbs/in The undertray is made fromCoil over Spring by Eibach A properly tuned spring system provides the muscle needed to transform the power derived from the engine of a racing car to the track through optimum adhesion. Suspension tuning is a precise balance. On one hand, the spring system should be soft enough to compensate for road irregularities assuring permanent road contact, while on the on the other hand the spring system must be firm enough to reduce the body roll, squat, and