Perrin Recirculating Blow Off Valve 2002-2007 WRX / 2004-2021 STI
Adjustable relief pressure and flow control makes fine-tuning on the fly simple and quick with the PERRIN BOV/BPV. HIGH FLOW With large 1.225" inlets and outlets, the PERRIN BPV is sized perfectly to relieve any amount of boost pressure without fear of compressor surge. Don't be fooled by giant oversized bypass 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. RECIRCULATION IS JOB #1 It is vital that a blow off valve for your WRX/STI recirculates the air back into the intake track to maintain proper air-fuel ratio and driveability between shifts. While this can be set up as a vent to atmosphere style blow off valve, we only recommend that on cars running an aftermarket Speed Density type tune. NO TUNING REQUIRED Increase horsepower and torque without ECU recalibration or tune! This part is designed and tested to work safely on your vehicle without any tuning