If you've been in the Subaru game for long, you're probably well aware that a 3-port Boost Control Solenoid (BCS) is considered by most to be a 'must have' improvement before having your car tuned. GrimmSpeed has become the trusted brand in the BCS market, with tens of thousands of solenoids in operation today across the globe. The 2015 WRX offers a unique change of pace, as the factory 2-port solenoid is mounted directly to the plastic turbo inlet and interfaces with an o-ringed feature, rather than a vacuum hose. With expertise in designing machined parts and a tried and true boost control solenoid, we were excited to dig in and create a solution with an already proven pedigree of high performance and quality.

THE 3-PORT ADVANTAGE

The advantages of a 3-port boost control system vs. the factory 2-port system are readily apparent during the tuning process. The 3-port system works by interrupting the boost signal traveling from the turbo to the wastegate. That boost is redirected back into the turbo inlet and re-ingested by the turbo using our machined adapter. This is important, as the factory Mass Airflow Sensor has already measured that air and is expecting that your motor will use it during combustion, rather than venting it to the atmosphere. The factory configuration simply 'bleeds' the signal from between the turbo and wastegate, which creates a system that is a bit less complex, but reacts more slowly and with less precision. The chart above shows two boost plots. The 'before' is our 2015 WRX, dyno tuned by a third-party pro tuner. The 'after' is the exact same tune but after the installation of the GrimmSpeed 3-Port BCS. As you can see, the addition of the GrimmSpeed BCS shows much tighter boost control and consistency. This is safer for your car and easier for your tuner.

PLEASE NOTE

• Because this upgraded solenoid affects the way that your vehicle controls boost (that's the point!), it is always recommended that you consult with a tuner immediately following installation. It is not recommended that you drive the car in a way that builds a boost without doing so. If you have any questions, don't hesitate to get in touch with us directly!
  

APPLICATIONS

• Subaru WRX (w/ factory composite turbo inlet) (2015, 2016, 2017, 2018, 2019, 2020, 2021)
  
• All FA20 Equipped Vehicles (w/ factory composite turbo inlet)
  

FEATURES

• Custom Machined Adapter - Makes use of the factory inlet recirculation port, instead of blocking it off
• Black Anodized Finish - Protects the assembly from corrosion in an extremely demanding environment
• 1/4in Barbed Fittings - Matches the factory turbo and wastegate hose size
• 3-Port Solenoid - Proprietary internal modifications prepare the solenoid for extreme conditions below the vehicle
• Plug-n-Play Wiring Connector - Plugs directly into the factory wiring harness with no modification required
• Compact Design - No need to mount the solenoid elsewhere in the engine bay, increasing complexity and hose length

KIT INCLUDED

• GrimmSpeed 3-Port Boost Control Solenoid w/ Plug-n-Play Connector
• Machined and anodized turbo inlet adapter w/ VITON O-Ring
• Laser Cut and CNC bent steel bracket, black zinc plated w/ stainless press-in nuts
• Zinc plated barbed fittings, preassembled w/ anaerobic sealant
• 2ft of 1/4in Vacuum Hose w/ zip ties
• All necessary hardware