The Radium Engineering FHST (fuel hanger surge tank) is compatible with all BMW E90/92/93 3-series with the N54 or N55 engine.

NOTE: This system is compatible with the E90/92/93 M3 fuel tank, however the stock M3 fuel pump cannot be controlled with the factory fuel pump controller, advanced system modifications are required to overcome this issue. This is not covered in the installation instructions and is up to the installer to devise a solution.
The Fuel Feed Kit is NOT compatible with the M3.

Overview
The Radium Fuel Hanger Surge Tank is a revolutionary way to eliminate fuel starvation that can occur during high performance driving, while also providing a way to upgrade the fuel pumps for high-horsepower engine modifications. This system installs inside the BMW fuel tank on the opposite side of the factory fuel pump and can hold one or two high-flow aftermarket fuel pumps. The stock fuel pump is used to pump fuel into the FHST, while the pumps inside the FHST then supply fuel to the engine. The system is E85 compatible and does not require any permanent modifications for installation.
Read below to see how the FHST works.

BMW Fuel Tank
The OEM saddle bag fuel tank is quite complex. The venturi jet pump is driven by the feed line instead of the return (M3 has 2 venturi jet pumps). The post pump filter and FPR are integrated into the LH side of the tank where the FHST mounts.