1" drop front and rear. Matched spring rates for PASM dampers Direct replacement spring set no modifications needed to vehicle Absolutely NO SAGGING with our springs Springs are TUV approved, manufactured to higher than ISO 9001 GMG "World Challenge" Sport Lowering spring sets for Porsche 997TT. GMG WC Sport Lowering Spring sets are made to GMG's exact specifications. Unlike some most tuners who simply take an off the shelf lowering spring and rebrand it with their name, we choose to develop a completely new design that would not only improve the handling of the 997TT but would also improve the comfort and ride quality while maintaining maximum control and remaining fully compatible with the Porsche Active Stability Management (PASM) dampers. Learn More