Boost Control Solenoid 4 Port Thread: 1/8 NPT

Haltech Boost Control Solenoid — 4 Port, 1/8 NPT (HT-020401)

The four-port solenoid, specified when you need control over a wider range of boost pressure than a three-port can deliver. Running 33Hz PWM off any Haltech ECU output.

Four ports give the ECU authority over both sides of the wastegate diaphragm with a dedicated vent path, which is what lets you hold the gate closed well above spring pressure and then bleed it precisely at target. On a big single turbo where spring pressure sits far below where you actually run, that range is the difference between hitting your number and living with whatever the gate gives you.

1/8 NPT porting throughout.

Everything for the install is in the box — four 1/8 NPT to 5/16 barb fittings, a brass vent, the DTM2 connector set, an M6 isolated mount, and a mounting bracket with hardware. The isolated mount matters: solenoids buzz, and hard-mounting one to a chassis rail turns the whole car into a speaker.

Off-road and competition use only. Haltech products are sold for sanctioned off-road and competition non-emissions-controlled vehicles, and it's the installer's responsibility to comply with local and federal regulations.