Grimmspeed Bypass Valve Red 2004-2021 STI / 2002-2007 WRX
Here, you are looking at the Grimmspeed Bypass Valve for your STI, WRX, Baja, or FXT.
- 2004-2021 Subaru STI
- 2002-2007 Subaru WRX
- 2006-2008 Subaru Forester XT
- 2004-2005 Subaru Forester XT (with STI-Style TMIC)
- 2004-2006 Subaru Baja XT (with STI-Style TMIC)
Grimmspeed started the ground-up design with the valve body and base for each popular fitment. Both are CNC-machined out of billet 6061 aluminum alloy for its strength and light-weight. They are then anodized in either a black or red finish to give them a brilliant appearance, provide corrosion resistance and match other GrimmSpeed offerings. Compared to the stock cast unit on the EJ STI platforms, GrimmSpeed Bypass Valves not only stand out, but are guaranteed to stand the test of time.
For the internal components of the valve, Grimmspeed chose to utilize a machined brass piston for its anti-corrosion and low thermal expansion characteristics. The piston seats onto an internal o-ring to create a perfect seal, eliminating boost leaks common in OEM and cheap aftermarket BPVs. In order to make sure this could keep up with high power levels, GS chose to use a massive 38mm diameter piston/sealing ring for the ability to dump pressure quickly. This is especially important on high boost applications to keep the turbo from sustaining damage and the BPV maintaining leak-free operation. A precisely-tuned steel spring alleviates the need for any tuning or adjusting of the valve, with no engine tuning required to run the unit. Buna-N O-rings were the next logical choice due to their resistance to degrading from fuel and oil exposure. In addition, all of our o-ring grooves utilize a single dovetail design for superior retention. This guarantees the o-ring will not fall out and has the perfect crush for sealing the body together. To top things off, we employ a swivel fitting on the valve to make for easy installation and accommodate best-routing on custom setups. A GrimmSpeed signature branding badge graces the top of each unit so that everyone will know you chose the best valve in the biz.
With the GrimmSpeed Bypass Valve installed, a definite crispness and sound change is noticeable through the intake and due to the leak free nature of our valve, the car builds boost much more quickly over the leak-prone OEM version. Both the 08-14 WRX/05-09 LGT and 04-21 STI (EJ) fitments utilize the same valve but with different footprints, for use across a broad range of vehicles including Legacies, Foresters and Bajas with the proper intercooler setup. The STI unit reuses the recirculating elbow from the factory BPV, ensuring precise alignment and a perfect fit. All this makes for a total plug-and-play package.
- CNC-Machined 6061 Aluminum
- Corrosion resistant anodized finish, available in both red and black
- Oversized 38mm brass piston for superior flow
- Precision-tuned steel spring for long life
- No tuning or adjustment required
- Single dovetail o-ring grooves with Buna-N O-rings for great oil resistance, retention, and leak free operation
- Swivel air fitting to aid in install and for accommodating custom setups