Radium is proud to release the first ever fuel pressure regulated surge tank. The innovative FST-R (Fuel Surge Tank - Regulated) is a fuel surge tank that houses a single internal fuel pump and has a fuel pressure regulator integrated in the top cap. This revolutionary idea eliminates the need for an external regulator along with the extra hoses and fittings associated with it.
This setup offers multiple benefits:
1. Reduced overall system cost
2. Reduced fittings resulting in less potential leak/failure points
3. Reduced hoses resulting in a lighter FST system
4. Reduced fuel temperature from the elimination of fuel returning from the engine bay
4. Quicker, easier, and cleaner installation
The FST-R is machined from 6061 Aluminum and like all Radium Engineering products, it is fully anodized and compatible with all fuel types.
The integrated fuel pressure regulator has all the features of a market-leading regulator. The output pressure is adjustable using the screw on the top cap. It is also capable of 1:1 vacuum reference by securing a vacuum hose to the nipple on the top.
The clean and compact package does not add significant size to the Radium fuel surge tank. The regulated output port is located on the side of the cap.
Shown above with an AEM 50-1200 E85 compatible fuel pump.
Inside the surge tank, many of the popular fuel pumps we currently supply can be used including: AEM, Walbro, Deatschwerks, and Aeromotive. At this time, the FST-R can only hold a single fuel pump. If a dual pump surge tank is needed, please see our other surge tank offerings:
The regulator features interchangeable orifice sizes to match the output of different pumps.
When purchased with a pump, the FST-R will come fully assembled and pressure tested. Radium assembles the FST-R with the properly sized orifice for the pump. Two extra orifices are provided should the user ever decide to change pump.
A fuel pressure gauge/sensor should be installed on the high pressure output line (or fuel rail) to adjust the regulator. The Radium Fuel Pressure Gauge is perfect for this duty.
This FST-R works by converting to a returnless dead-end system. Unlike a "returning" fuel system, fuel sent to the fuel rail(s) is not returned back to the fuel tank. See the diagram below which shows the difference between a returning and a dead-end system.
One of the benefits of a dead-end system is that fuel heated by the engine is not circulated back to the surge tank or main fuel tank. This keeps heat out of the fuel system. Most modern vehciles use a dead-end fuel system for this reason and for improved EVAP emissions.
Is fuel flow restricted or fuel delivery "uneven" in a dead-end system? See the picture below of Dean Kearney's Formula Drift Viper which utilizes a dead-end system. Notice the FPR mounted in the image. This car runs a single -8AN hose up to feed the 1,000+Hp engine.
Radium also has extensive experience with E46 BMW fuel systems for S54 (inline-6) engines making over 1,000whp. BMW is one of many manufacturers that use dead-end fuel systems. Radium also successfully runs a dead-end system on their turbocharged Lotus Elise.
Radium's Lotus Elise running a prototype FST-R and dead-end fuel system. The OEM Lotus (and Toyota) fuel system is returnless as well.
Please feel free to contact Radium Engineering with any questions about your fuel system needs: firstname.lastname@example.org.
The RADIUM FST-R is in stock and ready to ship, see details here: