Grimmspeed 3-Port Electronic Boost Control Solenoid 2008-2014 WRX / 2005-2009 Legacy GT / 2005-2009 Outback XT / 2009-2013 Forester XT

GrimmSpeed is proud to offer the most complete, reliable, and easy-to-use 3-Port Electronic Boost Solenoid available for turbocharged Subaru models. Unlike the factory 2-port solenoid, the GrimmSpeed BCS delivers extremely high-resolution boost control, giving your tuner the precision needed for stable, predictable, and safe boost levels. Expect quicker turbo spool, tighter boost regulation across the entire RPM range, and consistent performance thanks to a balanced valve design capable of handling up to 120 psi without sacrificing response time.

Quick Specs

• Faster Spool: Flows 10% more than competing solenoids
• Plug-and-Play: Direct connection to the OEM harness—no wire splicing needed
• Factory ECU Compatible: Custom coil designed to operate safely with the Subaru ECU
• Durable Hardware: Nickel-plated fittings instead of fragile plastic
• Simple Install: Takes about 15 minutes with our detailed written and video guides

GrimmSpeed reimagined the Subaru boost control solution by developing vehicle-specific mounting brackets that allow the solenoid to install with a true factory fit and finish. The unit uses an OEM-style Subaru connector, making installation as easy as unplugging the stock solenoid and plugging ours in—no cutting, crimping, or modifying your factory wiring harness.

At the core of the system is a custom MAC-built valve, engineered specifically for GrimmSpeed with proprietary seals and components. MAC manufactures pneumatic control devices for demanding industrial environments where reliability is non-negotiable, and we leveraged their expertise to create a valve that withstands extreme heat, moisture, vibration, and pressure. With high-temperature coils and response times of 6 milliseconds or less, this solenoid delivers unmatched consistency. The design has also been proven safe and effective through collaboration with top Subaru tuners across the country.

Materials and Construction

• Weather-sealed Subaru harness connectors, crimped in-house using professional DELPHI tooling
• Laser-cut, black-zinc-plated brackets for maximum corrosion resistance
• Threaded PEM nuts pressed into each bracket for reliable, strip-free hardware engagement
• Low-profile 1/8" NPT nickel-plated fittings, oriented for clean hose routing and sealed with 120 psi-rated thread compound
• Vibration-resistant design engineered for long-term durability

Installation Instructions