Turbo lag is the enemy of any turbocharged vehicle. Our 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 diapharm ratio provide preformance that cheep piston types can not offer. The spring stiffness adjustment screw and the two different sizes give the GReddy user the option to match vehicles with mild upgrades to heavily tuned engines. Also available in easy to install kit form for most Japanese turbocharged vehicles.