Fuel Pressure Regulators

Customers fit regulators from this range to Subaru WRX and STI, Mitsubishi Evo, Nissan SR20 and RB platforms, Toyota 2JZ and 1JZ builds, Honda K-series, and Toyota GR86 / Subaru BRZ conversions to a return system. Plenty go onto LS and Barra swaps and dedicated race cars too. Most regulators are universal, so it is the plumbing and mounting that decides the fit, not the badge on the car.

• Adjustable bypass regulators for return-style fuel systems
• Compact regulators for single-pump street builds
• High-flow regulators for twin-pump and surge tank setups
• Gauges, port adapters, AN fittings and mounting brackets

A regulator's job sounds simple: bypass surplus fuel back to the tank and keep the rail at a set pressure above manifold reference. Doing it well is harder. Cheap units suffer pressure creep at low flow, chatter at high flow, and swollen diaphragms on E85.

The units we choose to carry use fuel-safe diaphragms and seals, machined bodies with ORB or AN ports, a 1:1 boost reference so pressure rises with manifold pressure, and a gauge port so base pressure can be set properly. Sizing matters as much as brand. A regulator suited to a stock-pump street car will be the restriction on a twin-pump E85 build, while an oversized one can be unstable at idle on a mild setup.

Most regulators here are universal and mount to the chassis, firewall or a fuel rail bracket. Check port sizes before ordering: inlet and outlet are commonly -6AN or -8AN, with the return sized to suit pump output. Builds converting a returnless factory system need a return line run to the tank, which is the bulk of the work.

Installers usually also need PTFE or E85-rated hose, AN fittings and adapters, a liquid-filled or electronic fuel pressure gauge, and a vacuum/boost reference line to the intake manifold. Base pressure should be set with the engine running and the reference line off, then rechecked once connected. Any change to fuel pressure needs a retune before the car sees load.

• Fuel rails with the port sizing to match your regulator
• Fuel injectors sized for your target power and fuel
• Fuel pumps and fuel pump hangers
• Fuel surge tanks for hard cornering and low-fuel control
• Fuel line kits, fuel filters and fuel system accessories
• Back to the full fuel system range

Do I need a regulator if my car is returnless from factory?
Not until you convert to a return system or run a rail that requires one. Once a return line and bypass regulator are fitted, rail pressure is controlled mechanically instead of by the pump controller.

What base pressure should I set?
Follow your tuner's figure. Many builds start near the factory static pressure so injector data stays close, then adjust from there.

Are these regulators E85 compatible?
The units in this range are built with ethanol-compatible seals and diaphragms. Check the individual product page for the manufacturer's fuel compatibility notes.

Can one regulator handle twin pumps?
Only if its bypass flow capacity suits the total pump output. Undersized regulators cause pressure to climb at low injector duty.

Do you ship Australia-wide?
Yes, we ship nationwide and all products carry the manufacturer's warranty.