AST Suspension Lowering Springs for the 2005-2009 BMW Z4 (E85) will lower that center of gravity without giving in a lot of the comfort you are used to with the OEM springs. The lowering springs are a direct replacement of the OEM springs and have been developed especially for each specific vehicle. Made out of the best material on the best Wafios coiling machines available.
AST Suspension Lowering Springs are manufactured from a premium high tensile chromium-silicone wire which is handpicked by AST engineers for its quality and metal consistency. Each spring is cold wound and then heat treated to increase hardness and reduce internal stresses present after winding. Each spring is then individually shot peened, phosphate treated and then powder coated to outlast even the life of the vehicle.
We recommend that our lowering springs be installed by a specialist workshop having the experts and special tools. Prior to assembly, it is absolutely necessary to read the TUV expertise comparing it with the data of the car and the delivered chassis part in order to exclude future assembly and technical problems concerning the TUV.
Brake Power Regulator
If the vehicle is equipped with a load-dependent brake power regulator on the rear axle, we recommend checking this regulator and having it re-adjusted by your specialist workshop.
Vehicles equipped with an anti-blocking system: the sensors have to be accurately re-adjusted after mounting our lowering springs.
Vehicles equipped with level adjustment: requires re-adjustment after mounting our lowering springs.
After our lowering springs are installed, wheel adjustment values must be checked.
The lowering indicated by us results from the difference between the standard ride-height (distance between fender and the center of the wheel) and the ride-height after lowering. You should take into consideration that in case of lowering carried out by the factory, the dimensions are reduced by this lowerage.