Please note: No pumps are included with any of these kits. They can be purchased separately.
WHAT IS A SURGE TANK? A fuel surge tank is designed to prevent fuel starvation on vehicles with inadequate fuel tank baffling. Fuel is supplied to the surge tank by a lift pump, which in most cases is the OEM in-tank fuel pump. The volume of fuel inside the surge tank acts as a buffer to always keep the FST pump(s) supplied with fuel, even if the lift pump starves momentarily. This volume is maintained by the lift pump as well as the fuel returning from the built-in fuel pressure regulator.
Excess fuel in the surge tank is returned back to the vehicle's main fuel tank. The surge tank also provides a quick and easy way to upgrade any standard fuel system without opening the stock fuel tank. This is an excellent fuelling solution for vehicles installing large demand power upgrades such as forced induction. For more information on how a fuel surge tank works,
MULTI-PUMP FUEL SURGE TANK-REGULATED (MPFST-R) The Radium Engineering MPFST-R is the perfect solution for simplifying a high power vehicle experiencing fuel starvation during aggressive driving. When compared to a typical surge tank, there is one less port fitting. Instead, the built-in regulator returns low pressure fuel directly into the surge tank negating the need for an external FPR return line.
PLUMBING The fuel pump outlets merge through a built-in fuel pressure regulator and exit the MPFST-R via a single outlet simplifying external plumbing. And because the compatible pumps utilize check valves, staging is permitted. This "FUEL PUMP OUTLET" port is 10AN ORB threaded but comes preinstalled with a -8AN male adapter fitting. The "OVERFLOW", "SUPPLY", and "RETURN" ports are all 8AN ORB threaded but come preinstalled with -6AN male adapter fittings. All of these fittings can be swapped out with different sizes (sold separately). Fuel enters the large canister from 2 sources: the built-in FPR and the lift pump. During this process, the fuel flow gets redirected and runs tangential through the canister creating a swirl pot. This helps eliminate unwanted air bubbles and fuel foam that can affect fuel pump and engine performance.
FILTRATION All pumps use the provided stainless steel mesh inlet screen for pre pump filtration shown above. As depicted below, fuel cannot pass between the 3 independent filtration chambers (A, B, C). NOTE: If less than 3 pumps are installed, the empty port does NOT need to blocked off.
ELECTRICAL The fuel pump power connections are handled with specially designed anti-rotation high-current electrical studs. Necessary ring terminals and hardware are included with every surge tank.
BUILT-IN REGULATOR RA-series regulators feature the first tool-less pressure adjustment. A jam nut and set screw are no longer required. With a simple turn of the knob, pressure will be increased or decreased. Additionally, there are no inherent air (vacuum/boost) leaks through the threads that traditionally a smoke detector would pick up. To aid in adjusting pressure, there are incremental detents that provide haptic feedback to the user. Every detent permits 1psi (+/-0.5psi) of adjustment depending on current fuel pressure. Furthermore, RA-series regulators feature a 360 degree swivelling vacuum reference port that is double O-ring sealed. This is the first in the industry. It permits the installer to quickly point the vacuum fitting in any direction with no tools required.
There are 4 interchangeable 10-32 threaded vacuum port fittings provided to cover all scenarios.
1. Barbed Fitting: A black zinc-plated 3/16" (5mm) barb machined from high strength steel that is compatible with the following vacuum hoses: 5/32" (4mm), 3/16" (5mm), and 7/32" (6mm).
2. 3AN Male Fitting: A black zinc-plated adapter machined from high strength steel that is compatible with 3AN hose ends.
3. Push-To-Connect: A nickel-plated brass fitting with Buna-N O-rings that is compatible with hard plastic 1/4" OD tubing.
4. Vacuum Plug: A black oxide stainless steel screw that is used to maintain a constant (non dynamic) fuel pressure. Beginning in the mid 1990s, vehicle manufacturers started transitioning to returnless fuel systems to lower EVAP emissions. To keep temperatures lower, these regulators are mounted inside the tank and do NOT have the ability to be vacuum referenced. This plug would be required in this scenario.
The MPFST-R features an 1/8" NPT fuel pressure port at the regulator. An 1/8" plug is provided. However, a fuel pressure gauge or sensor can be installed to adjust and monitor fuel pressure.
PUMP COMPATIBILITY As described below, the Radium Engineering part number will determine which fuel pumps can be used inside the specific MPFST-R.
20-1445 MPFST-R, PUMPS NOT INCLUDED, WALBRO GSS342 OR AEM 50-1200 OR DW440 This MPFST-R comes ready for the end user to install 1, 2, or 3 pumps.
PUMP COMPATIBILITY
- Walbro GSS342
- AEM 50-1200
- Deatschwerks DW440
20-1446 MPFST-R, PUMPS NOT INCLUDED,
BOSCH BR540 OR DW400
This MPFST-R comes ready for the end user to install 1, 2, or 3 pumps.
PUMP COMPATIBILITY
- Deatschwerks DW440
- Bosch BR540 (does not come with a check valve)
NOTE: Because of the physical pump size,
3 pumps can NOT be installed if using the optional fuel level switch.
20-1447 MPFST-R, PUMPS NOT INCLUDED, WALBRO F90000267/274/285
This MPFST comes ready for the end user to install 1, 2, or 3 pumps.
PUMP COMPATIBILITY
- Walbro F90000267
- Walbro F90000274
- Walbro F90000285
- Walbro F90000295 (does not come with a check valve)
