The APS Dual-Vent blow off valve for the WRX and STI features a 30 micron hard anodized, T6 billet aluminum body, low friction bronze piston, stainless steel spring, and Viton o-rings for a perfect seal that can never leak.

The large primary vent of the APS valve is designed to plumb back into the your car's inlet tract and ensures the best driveability during cruise conditions. More importantly, the APS Dual-Vent BOV cures the problems seen with after market vent to atmosphere blow off valves by retaining all metered air under low and medium load conditions. During spirited driving and the turbocharger running high boost pressure levels, the APS dual-vent BOV continues to vent through to the second stage port in order to expel the maximum amount of charge air possible. This unique second stage vents directly to the atmosphere and will sound off with the classic blow off valve sound.

Adjustments to the APS dual-vent blow off valve can be done through the actuation adjustment screw allowing you to tune the venting characteristics to suit your driving style and modification level.