Hitman Nitrous System Holley 4150

The Hitman Nitrous System by Nitrous Express is a wet, single-stage nitrous oxide system engineered to deliver 100–200 horsepower gains on square-bore carburetors. This 10-pound bottle kit represents a proven platform for bolt-on performance enhancement on small-block and mid-size engines where carburetor-based fuel delivery remains the standard. The wet-system design injects both nitrous and fuel atomization at the intake, maximizing combustion efficiency and minimizing the risk of detonation under full load.

The 10-pound bottle capacity provides sufficient charge for multiple runs and street-performance scenarios without requiring frequent refills. Single-stage operation keeps the system straightforward—one lever activation cycles the entire system on or off, eliminating the learning curve of multi-stage tuning. The white powder-coated bottle and stainless fittings resist corrosion in varied storage and climate conditions. For square-bore Holley 4150-pattern carburetors, fitment is direct and requires minimal modification to existing intake plumbing. The system weighs 21.4 pounds assembled, making installation manageable on most engine bay configurations.

This platform suits enthusiasts seeking straightforward bolt-on power for street cars, weekend cruisers, and bracket-racing applications where mechanical simplicity and reliability matter. Carburetor-fed engines—particularly those running naturally aspirated small-blocks—benefit most from the predictable, linear power delivery this single-stage wet system provides. Proper jetting and fuel supply tuning are essential for optimal results; consultation with engine tuning guides or Nitrous Express documentation ensures safe operation within the stated 100–200 horsepower range.