The previous generation Subaru’s that utilize side feed injectors are limited to specific flow sizes as well as a large expense to completely convert the system over to top feed. IAG provides a simple fuel rail solution that lowers the conversion cost to top feed injectors on older STI’s, Foresters XT's and Legacy GT’s. The conversion kit allows you to keep your side feed TGV’s in place, simply swap in our injector conversion bosses, new conversion rails, hardware and your choice of top feed injectors*.
The IAG Performance Side Feed to Top Feed Fuel Rail Conversion Kit is designed to increase the power ceiling on your Subaru's fuel system. The factory fuel rails function in a series, which means that each cylinder's fuel is delivered after the other. As horsepower rises past the 350whp mark, the stock rail often does not have the capacity to deliver fuel to the last cylinder effectively. As a result, that last cylinder can run lean, which can result in catastrophic failure. The IAG billet fuel rails are designed to eliminate this problem.
First, our fuel rails operate in parallel format, each cylinder bank receives equal fuel, matching the flow between the rails ensure that each injector sees the same fuel pressure. Second, the bore of our rail is machined to 5/8in ID and is designed to accept -8 O-ring boss fittings. This configuration greatly increases the volume of the rail which means that more fuel is available at higher power levels. These fuel rails were real-world tested to 850hp.
The fuel rails also feature a port to add an optional fuel damper between each pair of injectors. Fuel dampers absorb fuel oscillations caused by injectors opening and closing. All Subaru’s are equipped with a fuel damper however its location is some distance from the injectors. The IAG rails locate the damper between the injectors to smooth out the fuel flow.
The fuel rails are engineered and manufactured at the IAG facility in Westminster, Maryland. The rails are machined from a solid block of 6061 billet aluminum and feature an anodized finish with the IAG laser marked logo on the top.
(x2) Billet fuel rails
(x4) Side feed to top feed injector conversion bosses
(x4) Phenolic spacers
(x4) Injector O-Rings
Tested To Directly Fit:
Injector Dynamics 1050x, 1300x, and 1700x.
- Not compatible with Injector Dynamics ID2000cc injectors without switching out the billet top hat.
- Injector tension springs are available separately when trying to fit older Injector Dynamics (ID1000) fuel injectors. PN# IAG-AFD-2129
- This kit does not include fuel lines but they are available separately.
2004-2006 Subaru STI
2005-2007 Subaru Legacy GT
2004-2005 Subaru Forester XT