GrimmSpeed 15-21 Subaru WRX Bypass Valve

Fits Subaru WRX 2015 to 2021 Sedan (Base, Premium, Limited, Series.Gray, Series.White) ; Subaru Forester 2014 to 2018 SUV (2.0XT Premium, 2.0XT Touring) Black. Years supported: 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021. These valves are designed to be recirculating. They can be vented to atmosphere, but will require a custom non-MAF tune and modification of the return line. Also known as a Bypass Valve (BPV), the GrimmSpeed Recirculating Blow Off Valve allows you to have the sound and performance you love about a vent to air BOV while keeping the driveability and economy of a recirculating BOV. A bypass valve is an important piece of any turbo system. When you begin to increase boost or increase power to the engine, the stock valve begins to stress. GrimmSpeed tackles this by introducing their upgraded bypass valves. Built to operate even under the most stressful conditions, each valve is made of CNC machined 6061 aluminum and anodized in black or red for durability and longevity. The oversized 38mm brass piston allows for more air to bypass quickly and efficiently. Due to the way they are constructed, they do not require any tuning and can be used on a stock or tuned engine. The swivel air fitting makes this a simple install on any build. Key Features: Eliminates boost leaks often found when using OEM bypass valves. Solid CNC machined 6061 construction with corrosion resistant red or black anodized finish. Oversized 38mm brass piston for increased flow and quick actuation. The piston has a O-ring to eliminate any boost leaks seen in cheaper options. Precision tuned steel spring for a long operating life. Swivel air fitting to aid in install and for accommodating custom setups. No tuning or adjustments required!.