The Yellow Speed Premium Competition Coilover Suspension Kits for BMW Z4 M E85 vehicles are designed and developed for use in most motorsports. Through years of competition and testing, we have made uncountable improvements in setup for racing use in order to provide the most durable and competitive damper. Spring rates and shock valving are made for competition to make the vehicle more controlled and balanced. This suspension system features 33-way dampening adjustment and full length adjustment to accommodate every driver’s needs. The lower mounts are manufactured from lightweight alloy aluminium to reduce unsprung weight. The pillow ball top mounts are used on McPherson struts for maximum handling and performance.