GFB Subaru

• Blow off valves: Hybrid Dual Port, Respons Dual Port Variable, Mach 2 recirculating plumb back and Deceptor Pro II electronic BOVs.
• Diverter valves: DV+ units, including versions with an integrated solenoid for the latest WRX (VB/VN).
• Boost control: WGA internal wastegate actuators, plus universal EX38/EX44/EX50 external wastegates and electronic and manual boost controllers.
• Drivetrain: adjustable and basic short throw shifter kits for 5-speed and 6-speed Subaru gearboxes.
• Engine accessories: lightweight crank, alternator and water pump pulleys, and underdrive pulley kits.
• Service parts: replacement gaskets, inlet flange adaptors, springs, hose adaptors and blanking plugs.

Subaru turbo models changed inlet sizes and valve mounting arrangements across generations, so the chassis code is the key identifier. Common codes in this range include GC8 (1994-2000 WRX/STI, with separate 20mm, 33mm and 35mm/30mm era fitments), GDB/GD/GG (2001-2007), GRB/GR/GV/GH/GE (2008-2014), VA/VAB (2015-2021) and VB/VN (2022 onwards). Forester XT appears as SF, SG, SH and SJ, Liberty GT/B4 as BE/BH, BL/BP and BM/BR, and Levorg as VM/VMG.

Check the chassis code and build year on your compliance plate against the product title, and note that some listings are further split by model year (for example MY94-96, MY97-98, MY99-00 or MY03-05) because the factory valve differs. Replacement gaskets, springs and adaptors are listed against specific GFB part numbers such as T9003 or T9503, so match those numbers to the valve you already own.

Most GFB blow off and diverter valves bolt or clamp into the factory location using the supplied hardware, while wastegate actuators, pulleys and shifter kits require more extensive disassembly. Typical requirements include metric spanners and sockets, hose clamp tools, thread sealant for fittings, and a torque wrench for pulley and actuator fasteners. Electronic products such as the Deceptor Pro II and G-Force boost controllers also need switched power, earth and signal connections.

Installation by a professional workshop is recommended. Some valve and boost control changes may require tuning or an ECU check, and modifications can affect emissions and roadworthiness compliance in your state or territory.

What is the difference between a plumb back and an atmosphere BOV? A plumb back (recirculating) valve returns air to the intake, while an atmosphere valve vents it outside. Subarus with a MAF sensor generally suit recirculating or dual port setups; GFB's Dual Port valves allow a split between the two.

Will a GFB valve suit my WRX? Compare the chassis code and model year in the product title with your vehicle. GDB, GRB, VAB, VA and VB fitments all use different valve arrangements.

Do I need a tune after fitting one? Recirculating and dual port valves are usually designed to work with the factory tune, but any change to boost control or venting is best assessed by your tuner or workshop.