Collection: Blow Off Valves/ Waste Gates

Granatelli Motor Sports turbo blow-off valves and external wastegates handle both sides of boost control. The wastegate controls boost on the exhaust side by routing exhaust around the turbine. The blow-off valve protects the intake side by venting boost when the throttle closes, so pressure doesn't surge back through the compressor. Most turbo builds need both. Designed, engineered and tested in Oxnard, California.

External Turbo Wastegates: 44mm, 50mm & 60mm

Every Granatelli wastegate uses V-band mounting and comes with V-band flanges, clamps and a spring kit to set your boost. Choose piston-actuated for high-heat, sustained-load builds, or water-cooled diaphragm when the gate mounts close to the turbo or manifold.

• 44mm: 540261 piston or 540244 water-cooled, a compact gate for tight packaging
• 50mm: 540203 piston or 540202 water-cooled, more bypass without stepping up to a 60mm
• 60mm: 540260 piston or 540259 water-cooled, for big turbos that move a lot of exhaust

Not sure which size? Read 44mm vs 50mm vs 60mm Wastegate: What Size Do You Need? or shop all Granatelli external turbo wastegates.

Turbo Blow-Off Valves: 50mm & 64mm

• 50mm Adjustable – 540200: V-band, +6 and +15 psi springs included. Fits most turbo street builds.
• 50mm Ultra High Flow – 540201: same 50mm size with more room for air to get out.
• Viper Series – 540198: billet aluminum, adjustable spring preload, vents to atmosphere.
• 64mm Anaconda – 540199: billet 6061 aluminum for high-horsepower turbo and centrifugal supercharger builds with large charge piping.

Compare them side by side in Granatelli turbo blow-off valves.

Blow-Off Valve & Wastegate FAQ

Do I need a blow-off valve and a wastegate?

For most turbo builds, yes. The wastegate controls boost on the exhaust side, and the blow-off valve releases pressure on the intake side when the throttle closes. Read Wastegate vs. Blow-Off Valve for the full breakdown.

Does a blow-off valve add horsepower?

No. A BOV protects the turbo from compressor surge and helps the system respond cleanly between shifts and throttle lifts.

What comes with a Granatelli wastegate?

V-band flanges, clamps and a spring kit for setting boost pressure.

Is a vent-to-atmosphere BOV OK for my tune?

The Viper and Anaconda vent to atmosphere. Check with your tuner before installing, especially on MAF-based engine management.

Granatelli boost-control history: our wastegate work goes back to the early-1960s Novi IndyCar engines, and a Granatelli wastegate helped Mario Andretti win the 1969 Indianapolis 500. Questions? Call 1-805-486-6644, Monday–Friday, 8am–5pm PST.