Choosing to use the Silly Rabbit Motorsport modified S4 intake manifold, one with an adapter for the RS4 throttle body, meant that the stock S4 fuel rail setup could no longer be used. The larger RS4 throttle body interferes with the positioning of the S4 fuel rail. I had a choice of purchasing an RS4 fuel rail, or putting together a fuel rail setup using aftermarket parts.
I decided to go the aftermarket route primarily because I felt it would give me more options with how the fuel and air plumbing would be done.
So far I have been collecting AN fittings to work with the IE Fuel Rails. I also purchased the Integrated Engineering Fuel Pressure Regulator housing, shown at the rear of the driver side fuel rail.
Additionally I am working on cobbling together the vacuum lines that I am pulling off of the S4 fuel rail.
Also I have obtained (courtesy of Paragon Performance) some adapters for connecting the stainless steel braided line to the factory hard fuel lines.