Hitman Nitrous System Holley 4150

The Hitman Nitrous System Holley 4150 by Nitrous Express is a purpose-built wet nitrous oxide injection system designed for carburetor-equipped engines seeking significant horsepower gains. This single-stage system targets enthusiasts and street racers who demand reliable, repeatable power delivery from a carburetor platform without the complexity of fuel injection integration.

Built around the ubiquitous Holley 4150 carb mounting pattern, the Hitman system slots directly into existing engine bays, making it an accessible upgrade for restomod builds, vintage muscle cars, and classic hot rods. As a wet-system design, the Hitman nitrous kit injects both nitrous oxide and fuel through a single solenoid-actuated nozzle mounted in the carburetor's intake bell, ensuring stable air-fuel ratios across the RPM range.

Nitrous Express engineers the Hitman with premium-grade stainless steel and aluminum components rated for sustained boost cycles, while the integral safety systems—including a purge valve and backfire protection—ensure longevity even under spirited driving conditions. The system's single-stage configuration delivers a controlled, progressive power band ideal for street-strip duty where drivability matters as much as peak horsepower.