A fuel surge tank (FST) is designed to prevent fuel starvation to the engine on vehicles with inadequate fuel tank baffling. The FST fuel pump feeds the fuel rail(s). The volume of fuel inside the surge tank acts as a buffer to always keep the FST pump supplied with fuel. This volume is maintained by the main fuel tank's (lift) pump as well as the fuel returning from the fuel pressure regulator.
In the case of the FST-R, the regulator is built in to the surge tank and is recirculating fuel internally. Excess fuel in the surge tank is returned back to the vehicle's main fuel tank.
Installing a surge tank is also an easy way to upgrade the fuel pump of a vehicle without opening or modifying the OEM fuel tank.
The FST-R (Fuel Surge Tank–Regulated) is an all new design that houses a single internal fuel pump and has an integrated fuel pressure regulator machined into the top cap. The high-flow regulator is adjustable and features interchangeable orifice sizes. This revolutionary idea eliminates the need for an external fuel pressure regulator along with the extra fittings and hoses. This simplifies the installation, reduces overall cost, reduces weight, and eliminates potential leak points in the fuel system. Furthermore, this system permits cooler fuel temperatures as the fuel is not returning from the hot engine bay. Like all Radium fuel surge tanks, this universal product can be used on any fuel injected application and is compatible with all fuel types.
The side port is the regulated pressure output and is plumbed directly to the fuel rail(s). No additional fuel pressure regulator is required. Pressure adjustment is done using the adjustment screw located on the top cap of the regulator unit. A vacuum line hooks up to the nipple on the FST-R to achieve 1:1 vacuum reference. Note: returnless fuel systems commonly use a constant fuel pressure. In this case, the vacuum reference hose is not required.
The FST-R is no taller than a standard fuel surge tank with hoses installed.
Two interchangeable orifices are included with calculated flow diameters to match the fuel pump flow to the regulator. Furthermore, this added precision will resist diaphragm flutter and optimize pressure stability.
A fuel pressure gauge is needed in order to set and monitor fuel pressure and should be located along on the output line or at the fuel rail. The Radium universal fuel pressure gauge is perfect for this duty. Shown above is the gauge with the optional in-line Tee fitting.
OPTIONAL MOUNTING BRACKETS
The fuel surge tank can be mounted near the main fuel tank or in the engine bay. Mounting locations near heat sources or moving parts such as suspension components should be avoided. It should also be mounted away from common collision areas. Choose a bracket below that best fits your mounting needs.
Floor and Wall Mount - This bracket is laser cut from aluminum and powder coated black and can be mounted on the side or bottom of the surge tank.
Frame Mount - Because this bracket has a 90deg formed bend and is cantilevered, it is constructed from steel for superior strength. It is not only nickel plated to resist corrosion, it also allows for components to be grounded to the spare hole in the bracket. This assumes the bracket is mounted to an electrically conductive material such as a steel frame.
Angled Mount - This mounting bracket is used for vehicles that may have a limited mounting height. It can be mounted on a floor and against a wall. This bracket is made from laser cut aluminum and powder coated black.
WARNING: Operating, servicing and maintaining a passenger vehicle or off-road vehicle can expose you to chemicals including engine exhaust, carbon monoxide, phthalates, and lead, which are known to the State of California to cause cancer and birth defects or other reproductive harm. To minimize exposure, avoid breathing exhaust, do not idle the engine except as necessary, service your vehicle in a well-ventilated area and wear gloves or wash your hands frequently when servicing your vehicle. For more information go to https://www.P65Warnings.ca.gov/passenger-vehicle.