Not getting enough fuel to your Audi S4 engine can lead to disastrous results, including overheating and damaged engine components. Optimizing your fuel system will not only maximize your engine's output, but will protect it from potential damage. There's nothing worse than spending thousands of dollars on your Audi S4 engine, only to have your pistons crack from running the engine too lean. Replacing the factory fuel rail with an aftermarket Audi S4 fuel rail is one step in ensuring that your engine gets as much fuel as it needs.

As your Audi S4 engine's power is increased, its demand for air and fuel is also increased. While there are many ways to deliver more air, providing enough fuel is often overlooked. One of the biggest bottlenecks in Audi S4 fuel delivery can be the factory fuel rail, which is often too small in diameter to provide enough fuel to modified engines. An aftermarket Audi S4 fuel rail can help alleviate this problem with an increased bore that will keep more fuel available at the injectors and ready for combustion.

Q: Are fuel rails sold individually?
A: Fuel rails are sold individually unless otherwise noted.

Q: What do fuel rails do? Why buy fuel rails?
A: Fuel rails are designed to keep pressurized fuel flowing to the injectors. When high performance motors are built and the fuel pressure is increased, sometimes the standard bore on the fuel rail is too small, restricting fuel flow to the injectors and causing your car to lean out.

Q: How do you install fuel rails?
A: Fuel rails are installed by removing the injectors and fuel pressure regulator from your factory rail. The factory fuel rail is then removed and the new unit is installed in its place. Specialty tools are needed to remove the fittings on your standard rail and to install new fittings into the new fuel rail. This job should be left to the pros if you've never done a fuel rail before.