Stage X Side Feed Parallel Billet Fuel Rail Kit V5 - V6

Stage X billet fuel rails suit performance engine projects that use earlier side feed injectors and need improved fuel feed and routing.

In Subaru's standard fuel system, a pump feeds fuel from the tank to the front of the car, through the fuel filter in the engine bay and into the fuel rails. Fuel is then delivered to each cylinder one by one, starting with cylinder four. The fuel pressure regulator at the end of the rails acts like a flood gate, backing up fuel pressure so that each cylinder has a good supply.

A more efficient approach is to give every cylinder its own equal share of fuel so that none runs short compared to the rest. A parallel fuel rail design does this in a more effective, safer and better regulated way.

With this kit, fuel leaves the fuel filter and passes through a Y-piece separator that sends it to both rails at the same time. This solves the problem of one cylinder running lean and lets the system hold more fuel in reserve, thanks to the larger-diameter rails and lines.

This kit is designed for modified vehicles where fuel control is essential for maintaining power and engine safety. The added performance fuel pressure regulator gives maximum fuel control with minimum flow restriction for engines up to and exceeding 1500 HP. Developed with Advanced Bypass Technology and an enlarged port design for accurate fuel pressure control across the range, it lets the fuel pump push more, draw less current and always meet fuel volume demands with no pressure creep.

A remap after installation is recommended so that all ECU fuelling parameters are matched.

Each rail is precision cut from T6061 billet aluminium and finished in military-grade black anodising. The kit includes anodised steel -6 shouldered male fittings ready to connect to braided fuel lines, plus all necessary mounting brackets, stainless steel hex screws and rubber O-rings for a complete installation.

These rails are intended for use with standard Version 5 or uprated Version 5 Phase 2 type injectors.