GrimmSpeed has taken our bypass valve to the next level with a complete redesign of the internal piston, spring, and body for unmatched durability, performance, and style. After extensive testing, we addressed the weaknesses seen in the V1 design and created a valve that holds double the boost pressure of stock units while maintaining a sleek appearance under your hood.

In stock FA20 engines, OEM bypass valves have shown internal leakage at as low as 8psi and 19psi, respectively. GrimmSpeed bypass valves solve that problem with precision-engineered components and oversized 38mm pistons, ensuring fast, leak-free pressure relief even on high-boost setups.

Material and Design

• CNC-Machined Billet 6061 Aluminum – Lightweight, strong, and anodized finish for corrosion resistance and visual appeal
• Oversized 38mm Aluminum Piston – Allows rapid pressure dumping while maintaining perfect sealing
• Internal O-Ring Seal – Buna-N construction with dovetail retention prevents leaks and ensures long-term durability
• Steel Spring – Precisely tuned for optimal operation with no adjustment or tuning required
• Swivel Fitting – Allows flexible routing for custom setups
• Premium Branding – Signature GrimmSpeed badge for a clean, professional look
• No Tuning Required

Key Improvements Over V1

• Redesigned internal piston to eliminate previous failure points
• Optimized spring tension for improved response across all operating conditions
• Upgraded main body design for better CNC finish
• Replaced V1 brass piston with a lighter, hard anodized aluminum piston for faster response
• Removed unnecessary inspection port while maintaining quality control

FITMENT:

• 2015-2021 Subaru WRX
• 2014-2018 Subaru Forester XT