The Blow off valve is essential to all turbocharged vehicles. The purpose of the BLITZ Blowoff Valve DD is to relieve compressor surge without reducing compressor speed. It controls boost pressure that is built up by the turbo and vents it into the atmosphere when the car is not under load (in between shifts). This prevents pressure from backing up into the compressor housing, causing the turbo impeller blade to rapidly stop or even worse, to spin backwards (compressor surge or backspin). Doing so can be potentially destructive to the turbine wheel and shaft. Repeated stress over time can cause eminent damage to the turbo charger and eventually lead to turbo failure. A blowoff valve is actuated by pressure changes only, ensuring quick valve responses and complete closures at idle.

The Blow Off Valves are easily adjustable to prevent both premature boost leakage and compressor surge. Each is made of durable cast and billet aluminum frame and the valve to diaphragm ratio provides performance that cheap piston types cannot offer. The spring stiffness adjustment screw and 3 different sizes give the GReddy user the option to match vehicles with mild upgrades to heavily tuned engines. Also available in an easy to install kit form for many turbo charged vehicles. Blow Off Valve Type H: (BOV-H) Want a valve that people notice when it goes off but don't want "RFL-loud"? The BOV Type H is the valve for you. Providing greater venting flow than our BOV-S, the BOV-H is designed for turbo charged engines running up to 35 psi.