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, but, if you're running an aftermarket turbo setup, you may no longer be utilizing the factory turbo inlet. This product includes the solenoid with fittings and connector, as well as a universal mounting bracket, rather than the machined adapter required by the factory turbo inlet. We've also left the wiring harness longer to facilitate a number of different mounting locations, depending on your turbo setup.
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. 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 protuner. 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.
The GrimmSpeed Boost Control Solenoid has been proven time and time again. With tens of thousands on vehicles across the world, tuners trust it and our customers love it. What you see here is the same great solenoid with millions of miles of real world testing with a longer plug-and-play harness and universal bracket, allowing you to adapt it for use with an aftermarket turbo inlet.
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. If you have any questions, don't hesitate to get in touch with us directly!