Top Feed Conversion Kit

The IAG Performance Top Feed Conversion Kit is engineered to facilitate a complete conversion from side feed to top feed TGV/Rails/Lines for the 2004-2006 Subaru STI and 2004-2005 Forester XT. This kit goes beyond a simple fuel rail upgrade, integrating the IAG V2 CNC billet aluminum top feed TGV housings, IAG V3 top feed fuel rails, lower TGV gaskets, and custom braided fuel lines and fittings. The IAG V2 TGV housings are crafted to enhance performance by optimizing airflow from the intake manifold to the cylinder heads. They feature a larger inner port design that aligns with gaskets and ported cylinder heads, coupled with a refined surface finish for improved airflow. Additionally, the V2 housings are manufactured with weight savings in mind, weighing nearly 30% less than previous versions, and contribute to a cleaner engine bay by reducing component count, creating more space for aftermarket parts. The IAG V3 Top Feed Billet Aluminum Fuel Rails are designed to elevate the power ceiling of your Subaru's fuel system. Unlike factory sequential rails, these V3 rails operate in parallel, delivering equal fuel pressure to each cylinder bank. This parallel configuration prevents lean conditions in the last cylinders at higher horsepower levels and ensures consistent fuel delivery. The rails feature a 5/8" ID bore, designed to accept -8 O-ring boss fittings, significantly increasing rail volume and supporting higher power outputs—tested up to 1000hp. The V3 rails also include ports for an optional fuel pressure pulsation damper and phenolic spacers to reduce heat transfer to the fuel. Top feed fuel injectors are required and sold separately; IAG recommends Injector Dynamics fuel injectors. This kit is designed for use with the Aeromotive 13138 Fuel Pressure Regulator, which is also sold separately. The supplied hose requires custom cutting and fitting attachment. It is important to note that the standard hardware set may not be long enough for use with 3mm and 8mm phenolic spacers; optional hardware sets are available for these spacer sizes.