The Radium Engineering 02-14 Subaru WRX/STI Top Feed Fuel Rail Upgrade (Factory Top Feed Motors Only) upgrades the existing fuel-rail system with the additional hardware or plumbing needed for higher-flow performance use. It lets the supported application move beyond the stock fuel arrangement without replacing unrelated parts of the system.

This version is designed around 02-14 Subaru WRX/STI Top Feed, so the mounting, routing, or connection details should be checked against that application before installation. Injector height, upper/lower O-ring diameter, and plumbing requirements vary by engine. Match the exact application and injector configuration.