With large 1.225" inlets and outlets, the Perrin blow-off valve is sized perfectly to relieve any amount of boost pressure without fear of compressor surge. Don’t be fooled by giant oversized blow off valves, these inlet and outlet sizes were chosen to ensure the perfect balance of flow and to maintain boost in your system, without ruining response by dumping too much boost.
The Perrin blow off valve cap features adjustable spring tension, which allows for an adjustment when the blow off valve vents. Perrin's unique flow control design allows you to control the volume of air released when the blow off valve vents. Adjusting the volume of air helps maintain the perfect amount of boost in your system during shifts without causing compressor surge.
Red or black anodized aluminum body, black cap. Note, this does not come with a new gasket. One can be purchased here.
Fits all 2002-2007 WRX and STI, and 2008-2020 STI.