02-07 Subaru WRX & STI Perrin VTA Blow Off Valve

The blow off valve is essential to all turbocharged vehicles. The purpose of the Perrin 02-07 WRX & STI blow off Valve is to relieve compressor surge without reducing compressor speed. This Perrin VTA (vent to atmosphere) blow off valve for the 02-07 WRX & STI controls boost pressure that is built up by the turbo and vents it into the atmosphere when your Subaru 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, shaft, and turbo life in your WRX or STI.

If you are looking for that famous blow off valve noise, this Perrin vent to atmosphere BOV kit is the one for you. With exclusive harmonic amplification cutouts, this Perrin VTA Blow off valve is LOUD! Also, adjustable spring tension helps reduce rough idle and stalling commonly seen with lesser quality valves. Please keep in mind that this valve can NOT be set up to recirculate. If you do want your blow off valve to recirculate, check out the Perrin recirculating blow off valve kit for the 02-07 WRX & STI, available separately.