The APR R1 Diverter Valve is a critical performance upgrade recommended at all stages of performance as it replaces the failure prone factory unit. The R1 is designed to withstand extreme boost pressures at the highest levels of performance, while offering lightning fast response thanks to the unit's friction-free diaphragm-based design. Unlike piston based units that can stick and bind in the winter, the APR R1 is virtually maintenance free, requiring no greasing or o-ring replacements, as is common with other units. Constructed from CNC-machined billet-aluminum with a high-temperature Nomex-reinforced diaphragm, the R1 is designed to be the last DV upgrade the engine will ever need!