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 my 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 advantages of a 3-port boost control system vs. the factory 2-port system are readily apparent during the tuning process. The 3-port systems 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.
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 boost without doing so.
- 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/ anerobic sealant
- 2ft of 1/4in Vacuum Hose w/ zipties
- All necessary hardware