GMP Performance Bilstein B12 13 16 Porsche 911 Carrera 4 H6 3.4L 4S H6 3.8L Front and Bilstein B8 2003 BMW Z4 2.5i Front Left 36mm Monotube Strut Assembly GMP Performance VW MK7 Golf GTI Golf R Bilstein B8 (SP) Front 36mm Bilstein B8 2005 Porsche Boxster Base Rear 36mm Monotube Strut Assembly. Bilstein B8 Performance Plus (DampTronic) dampers are a performance upgrade to OE dampers designed to be paired with aftermarket lowering springs. All of the active features of the factory electronic suspension, along with the factory controls, will be retained with the installation of these dampers. Each damper is rigorously tested for quality that meets or exceeds OE standards and features application specific valve settings with a monotube design to bring out the best handling performance of a vehicle. B8 Performance Plus (DampTronic) dampers are the ideal solution for pairing with a lowering spring for improved handling and sportier look in a package compatible with factory electronic damping control. This Part Fits: Year Make Model Submodel 2006 2013 Porsche 911 Carrera 4 2012 Porsche 911 Carrera 4 GTS 2006 2013 Porsche 911 Carrera 4S 2007 2012 Porsche 911 Targa 4 2007 2012 Porsche 911 Targa 4S 2007 2013 Porsche 911 Turbo 2011 2013 Porsche 911 Turbo S