Grimmspeed Boost Control Solenoid For Subaru 15-21 WRX/FA20 Full Kit GrimmSpeedGRM 057041 An Elegantly Engineered Solution If you've been in the Subaru game for long, you're probably well aware that a 3 port Electronic Boost Control Solenoid (EBCS) is considered by most to be a 'must have' improvement before having your car tuned. GrimmSpeed has become the trusted brand in the EBCS market, with tens of thousands of solenoids in operation today across the globe. The 2015 21 WRX offers a unique change of pace, as the factory 2