The Radium Engineering fuel surge tank hanger can be used with up to three aftermarket high pressure pumps and 1 lift pump in the stock Mazda FD RX7 fuel tank. The unique integrated 1.85L surge tank completely eliminates fuel starvation. No grinding, bending, or modification of the trunk floor sheet metal is required./p>
A fuel surge tank (FST) is the best solution in preventing fuel starvation. Because the FD RX7 can experience high lateral G-forces, it inherently suffers from fuel slosh. Fortunately, Mazda manufactured a gas tank with a very large bolt flange pattern (similar to the FCST) permitting various upgrading options.
The returning low pressure fuel from the regulator is sent back into the FST keeping it full. A second 24 hole deflector is used in this location further preventing air bubbles and foaming. All of this happens inside the OEM gas tank.
INDEPENDENT INSTALLATION VIDEO
OPTIONAL FEED KITS
20-0455-03 Fuel Hanger Feed FD RX7 Stainless Filter
The feed kits use high flowing 8AN fuel lines. A Radium 1/2" fuel feed hose runs from the fuel pump hanger outlet to a Radium Engineering fuel filter secured to the rear subframe. From there a pre-made 8AN PTFE feed line runs all the way to the engine bay where it is up to the user to adapt the 45 degree hose end to their specific fuel system. The fuel lines clear the OEM fuel pump cover and all suspension related parts. No cutting or drilling is required to get the feed line past the fuel tank.
The included Radium Engineering fuel filter assembly mounts to the rear subframe underneath the vehicle using a specifically designed FD RX7 bolt-on billet mount.
The filter is mounted through a Radium Engineering heat exchanger to keep fuel temperatures down.
20-0455-05 Fuel Hanger Feed FD RX7 Microglass Filter
The feed kits use high flowing 8AN fuel lines. A Radium 1/2' fuel feed hose runs from the fuel pump hanger outlet to a Radium Engineering fuel filter secured to the rear subframe. From there a pre-made 8AN PTFE feed line runs all the way to the engine bay where it is up to the user to adapt the 45 degree hose end to their specific fuel system. The fuel lines clear the OEM fuel pump cover and all suspension related parts. No cutting or drilling is required to get the feed line past the fuel tank.
The included Radium Engineering fuel filter assembly mounts to the rear subframe underneath the vehicle using a specifically designed FD RX7 bolt-on billet mount.
The filter is mounted through a Radium Engineering heat exchanger to keep fuel temperatures down.
PLUMBING
To simplify aftermarket AN hose plumbing, the 10AN ORB threaded feed port features a low profile 8AN male fitting and the 8AN ORB threaded return port features a low profile 6AN male fitting. To reconnect the OEM feed and return hoses, barb fittings are also included.
The custom designed stainless electrical studs easily handle the high current demand that compact bulkhead connectors lack. These serviceable connections are properly sealed and impervious to all standard and exotic fuels. Nonconductive acorn nuts are provided to prevent any accidental short circuits. Furthermore, the high quality in-tank wiring is insulated with chemically resistant ETFE. Electrical hardware is included for the fuel pump(s), OEM level sender, and OEM temperature sensor.
NOTES
- Fuel pumps must be ordered separately. Some compatible pumps are sold on our website, but not all compatible pumps are available from Radium.
- A lift pump is required on all installations.
- Each kit includes wiring and pump connections to accommodate the same pump in the lift and surge tank positions. If you wish to mix different form factors of pumps, additional fittings, hoses, wiring, etc. will need to be purchased separately.
- The kits will come preassembled as shown below. Final assembly is performed by the installer.
- There are enough components included to run all 4 fuel pumps. Depending on the setup, some parts will simply not be used.
