The Cobb Tuning Boost Control Solenoid is designed to replace the factory Boost Control Solenoid with an uprated unit better suited to increased boost, external wastegates, or uprated turbos.A turbocharged engine regulates the amount of boost the turbo produces by controlling the amount of exhaust gas that goes into it. Excess exhaust gas is vented using the vehicles wastegate. This is literally a vent that opens and allows excess pressure out of the turbo.On many modern engines, this system is controlled electronically by a solenoid. Once you start seriously tuning an engine limitations in the factory system can start to be evident. The factory wastegate system will have only been designed to handle a certain amount of boost.Replacing this system with a Cobb Boost Control solenoid will remove boost fluctations inherent with the factory system ensuring stable and repeatable boost control.The advantage of a 3-port Boost Control Solenoid is that it can fully pert pressure away from the w