By-Pass Regulator

The by-pass regulator (SKU: QFT30-899) is a critical fuel system component designed for high-performance and custom fuel injection applications that demand precise pressure control. This in-line regulator serves motorsports enthusiasts, engine builders, and performance shops who require stable fuel delivery across a broad pressure range without sacrificing reliability. The bypass design allows excess fuel to return safely to the tank, preventing system over-pressurization and protecting injectors and carburetors from damage caused by pressure spikes.

Built from durable aluminum construction with corrosion-resistant blue and natural finish, the by-pass regulator features NPT female thread ports for both inlet and outlet (3/8 in.), plus a dedicated 3/8 in. NPT female return line. The regulator maintains fuel pressure between 4.5 and 9 psi, making it suitable for carbureted engines, naturally aspirated EFI systems, and fuel-injected applications running on gasoline, E85 ethanol blends, or methanol. The bypass mechanism diverts excessive fuel back to the fuel tank proportionally, ensuring consistent system pressure regardless of fuel pump output or engine load variations, without requiring external electronic control.

This regulator is ideal for street rods, classic car restorations, drag racing platforms, and custom fuel system installations where traditional mechanical regulation is preferred. Installation requires NPT-compatible fuel line fittings and a suitable mounting location in the engine bay or fuel cell area; the compact 3.55 x 2.25 x 5.7 inch footprint accommodates tight spaces. Weighing only 0.73 lbs, the by-pass regulator integrates seamlessly into fuel systems rated for E85, gasoline, and methanol without modification, ensuring broad compatibility across fuel types and platform applications for both amateur builders and professional shops.