PPE’s Ported Fuel Rail Fitting replaces the restrictive stock fitting. The fitting increases fuel flow volume from the CP3 pump to the fuel rail simply by making the whole bigger. Adequate fuel flow is vital to producing maximum horsepower. With the increased flow, the Ported Fuel Rail Fitting, is recommended for both high performance and race applications. You only need one fitting as this ftting benefits both fuel rails since the driver side fuel rail feeds the passenger side.