A 3-port Boost Control Solenoid (BCS) is considered by most to be a 'must have' improvement before having your car tuned. The 2015-2021 WRX offers a unique change of pace, as the factory two-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, GrimmSpeed has created a solution for the 2015-2021 Subaru WRX.
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 GrimmSpeed's 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 addition of the GrimmSpeed BCS shows much tighter boost control and consistency. This is safer for your car and easier for your tuner.
Note that this solenoid requires custom ECU tuning.
- 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
- 2 ft of 1/4in Vacuum Hose w/ zipties
- All necessary hardware
Fits all Subaru FA20 turbo cars, including 2015-2021 WRX and 2014-2018 Forester XT.