quick view Add to Cart Turbo XS Turbo XS 08-21 Subaru WRX STi Boost Control Solenoid Kit - WS08-BCS MSRP: $363.99 The TurboXS 2008 - 2021 Subaru STI Boost Control Solenoid is designed to replace factory 2 port boost solenoid with a 3 port. This part is required for great boost control on your WRX when using an aftermarket Downpipe or Upgraded Turbocharger.This Part... Add to Cart Add to Wish List Add to My Wish List Create New Wish List Compare