This is a MAC Valves 4-port boost control solenoid valve, used with aftermarket and OEM-based ECUs to modulate boost pressure with PWM duty-cycle control. Compared to a 3-port valve, the 4-port design routes pressure directly to both ports of a dual-port internal wastegate, allowing a lower spring-pressure wastegate to be used for improved low-gear response while still holding target boost in higher gears ('boost by gear'), and its normally-closed design defaults to safe, lower boost in the event of an electrical or duty-cycle failure. It uses 1/8 in NPT fittings and supports PWM-modulated ECUs such as Hondata and Cobb AccessPort as well as standalone systems.
Fitment: Universal application for boost control on turbocharged engines using a sealed dual-port internal (or compatible external) wastegate.