How to Match a Radium Fuel Pump and Hanger to Your WRX, EVO or Supra Build
Buying a radium fuel pump is not the same as buying the right one. The pump is only one variable in a system: the hanger, the filtration, the feed line and the regulator all decide whether the fuel actually arrives at the rail at pressure. Get the match wrong and you end up with a pump that stalls, a hanger that will not seat, or a setup that starves the engine the moment you load it in third gear.
This is a fitment walkthrough, in the order we work through it with UK builders: power target first, hanger second, pump third, filtration and damping last.
START WITH YOUR POWER TARGET, NOT THE PUMP
Every fuel system question starts with how much fuel the engine needs at full load. A stock-turbo WRX on pump fuel, a bolt-on EVO X and a 2JZ Supra chasing big boost are three completely different jobs.
Work backwards:
- Estimate your realistic crank horsepower at the boost you will actually run in the UK.
- Assume a brake-specific fuel consumption figure for your fuel type and work out the litres-per-hour your injectors demand.
- Add a margin of at least 20 percent so the pump is not running at 100 percent duty the whole time.
A fuel pump rated at a headline flow number rarely makes that number at 3 bar of rail pressure with 13.5 volts at the terminals. Always size against the flow at your real operating pressure, not the catalog peak.
WHAT A RADIUM FUEL HANGER ACTUALLY DOES
A fuel hanger is the carrier that sits the pump in the tank and feeds it. Radium Engineering's hangers solve the limitations of the factory plastic assembly: they hold larger pumps, they accept AN plumbing properly, and they keep the pickup fed under cornering and launch.
The mistake we see most is builders buying a pump first and trying to make it fit an OEM hanger. Match the hanger to the platform, then match the pump to the hanger.
WRX: WHEN THE OEM HANGER IS ENOUGH
On the 2015+ Subaru WRX, a mild build on the factory fuel system is often fine as long as duty cycle stays low. Where the platform usually needs help is not the pump but the crankcase side - blow-by contaminating inlet air and diluting the charge.
That is the job of the Radium AOS-R Kit for the 2015+ WRX. It is a coolant-heated air-oil separator that bolts in with factory-style fitment, removes oil vapour before it reaches the inlet, and reduces hydrocarbon carry-over. If you are building a WRX on a stage-two tune, sort the AOS-R before you spend money on a bigger pump.
EVO X AND EVO 7-9: PICK THE HANGER, THEN THE PUMP
The EVO is one of the clearest cases for a purpose-built hanger. Both the EVO X and the 7-9 respond well to a drop-in upgrade, but they use different kits:
- Radium Fuel Hanger, Mitsubishi EVO X (Pumps Not Included) - upgraded carrier supplied without pumps, so you can run your choice of Walbro or AEM unit.
- Radium Fuel Hanger Kit, Mitsubishi EVO 7-9 with Microglass Filter - a complete kit with an integrated microglass filter for clean, reliable delivery.
Choosing the hanger first tells you exactly which pump body fits, which outlet thread you are dealing with, and whether filtration is already handled.
SUPRA: FLOW FIRST, THEN DAMP THE PULSE
On the MK4 Supra, big single-turbo builds want volume. That means a large in-tank pump or a surge tank arrangement rather than fighting the stock basket. But high-flow pumps introduce a second problem: pressure pulsation.
The Radium Fuel Pulse Damper Kit, MK4 Supra smooths those pulsations for more consistent fuelling, which matters most at idle and part throttle where a stock ECU is trying to control fuelling tightly. It is a small part that fixes a real driveability fault on cars running big pumps.
If you are pushing well past what an in-tank pump can support, a surge tank is the next step. Radium's MPFST-R and RA Fuel Surge Tank with integrated FPR keep one to three high-flow pumps supplied and prevent starvation under aggressive driving.
MICROGLASS FILTERS AND WHY THEY MATTER
Filtration protects the pump, the injectors and the regulator. A microglass element gives you finer filtration than a coarse mesh sock without choking flow on a high-power build. That is why the EVO 7-9 hanger kit ships with an integrated microglass filter, and why it is worth pairing a hanger upgrade with proper filtration rather than reusing a tired stock sock.
WALBRO VS AEM: SIZING BY FLOW
The two pump families most builders run in these hangers are Walbro (F90000267, F90000274, F90000285, GSS342) and AEM (50-1200), plus options like the DW DW440. They do not fit the same hanger bodies, so confirm the hanger's pump compatibility before you order:
- Higher-pressure, high-boost builds need a pump that holds flow at 4 bar and above.
- Entry-level upgrades on pump fuel are usually served by a single in-tank pump in a good hanger.
- Ethanol and big-power builds should plan for more volume and consider a surge tank from the start.
FITMENT CHECKLIST BEFORE CHECKOUT
Before you add anything to the basket, confirm:
- Target horsepower and the fuel pump flow you need at your real rail pressure.
- The correct hanger for your exact platform and generation.
- Pump compatibility with that hanger (Walbro, AEM, DW).
- Filtration - microglass element versus stock sock.
- Whether a pulse damper or surge tank belongs in the plan.
MATCH THE SYSTEM, NOT JUST THE PART
A radium fuel pump only performs as well as everything around it. Size the pump to your power target, choose the hanger that fits your platform, then finish the job with the right filtration and damping. Buying from an authorised UK dealer means genuine fitment, correct part numbers and UK delivery, so your build goes together once and goes back on the road.
If you are not sure which hanger and pump combination suits your WRX, EVO or Supra, tell us the platform and the power target and we will point you at the right Radium Engineering parts.
