General description maXpeedingrods SP1 lowering coilover is designed for BMW Z4 Roadster E85 and Coupe E86 models, offering adjustable rebound damping and separate height adjustment without altering preload. This kit features developed damping oil and upgraded racing springs, along with an adjustable camber plate (for some vehicles), enhancing both performance tuning and the vehicle's appearance. All coilovers are assembled in a dust-free factory, ensuring high quality and longevity. Technical specifications Application: BMW Z4 Roadster E85 (2003-2009) 2.0 i, 3.0 i, 2.5 i, 3.0 si, 2.2 i, 2.5 si; BMW Z4 Coupe E86 (2006-2009) 3.0 si Quantity: 2 pieces front + 2 pieces rear Front top mounts: pillow ball top mounts Rear top mounts: rubber top mounts Damping: 24 levels rebound damping adjustable Spring rate Front: 10 kg/mm (560 lbs/in) Spring rate Rear: 8 kg/mm (448 lbs/in) Spring length Front: 180 mm Spring length Rear: 170 mm Adjustable height: lowering 1-3 inches Coilover overall length