Radium Fuel Hanger Surge Tank Add-On - Nissan 200SX S14, S15/Skyline R33, R34

Radium Engineering FHST Add-On - Nissan 200SX S14/S15 & Skyline R33/R34

This product is to be used with one of the Radium 20-063X fuel hangers. It is recommended to use a single pump hanger to feed the surge tank. The surge tank can then be equipped with one or two fuel pumps to feed the engine.

The Radium Engineering FHST (Fuel Hanger Surge Tank) Add-On is the ultimate solution for fuel starvation issues. Due to the saddle-bag style OEM fuel tank and insufficient baffling in late model Nissans, fuel slosh is common when driven aggressively. Unstable pressure resulting in a lean fuel mixture can cause engine damage. A stand-alone surge tank is an excellent device for eliminating fuel starvation issues, but installation can be complex. This add-on is a fully functional fuel surge tank mounted inside the OEM tank.

Simple plug-and-play connections are all that is required to attach the two systems together. The FHST Add-On utilises most of the Radium 20-063X-0X fuel hanger parts. The surge tank can hold 1 or 2 aftermarket pumps including brushless variations. With the addition of the fuel pump in the OEM location, there could be 2-3 pumps inside the fuel tank in total. Even with all of the extra fuel pumps, the FHST system is very straightforward and relatively simple to install.

No grinding, bending, or modification of the vehicle is required. The system is also compatible with all alternative fuels including E85.

What Keeps the Surge Tank Full?
The surge tank fuel pump(s) are supplied with fuel from 4 different sources:

1. The high-flow (low-pressure) fuel pump located in the OEM location.
2. The fuel returning from the fuel pressure regulator (FPR).
3. The fuel transfer from the integrated venturi jet pump siphon.
4. The one-way fill valve on the bottom of the surge tank.

Fuel Pump Compatibility
Both brushed and brushless fuel pumps are compatible with the FHST Add-On. Fuel pumps are not included.

• Walbro F90000267 E85
• Walbro F90000274 E85
• Walbro F90000285 E85
• Walbro GSS342 255lph
• AEM 50-1200 E85
• Ti Automotive E5LM (brushless)

Electrical
External high-current fuel pump wiring is provided for installing one FHST pump (1 relay, 1 fuse, and all associated wiring and hardware). To wire in a second FHST pump, a second fuse and relay are required. Consider the Radium 17-0031 DIY Wiring Kit.

There are 2 different FHST kits available, each specific to the fuel pump model to be installed (20-0700 / 20-0701).

Note: Because the fuel pump supplying the FHST (in the original pump location) will now operate at very low pressure (high flow), the OEM external fuel pump wiring will be sufficient for this lift pump.

FHST Add-On Features

• Simple Integration into Fuel Hanger
• Fuel Starvation Protection
• Anodised Aluminium Construction
• Permits 1 or 2 Surge Pumps
• Brushless Fuel Pump Compatibility
• High-Current Electrical Hardware
• Gasoline, Methanol, and Ethanol Compliant
• Stainless Steel Hardware and Clamps

Vehicle Fitment

• Nissan S14 200SX/Silvia (All Trims)
• Nissan S15 200SX/Silvia (All Trims)
• Nissan R33 Skyline (All Trims)
• Nissan R34 Skyline (All Trims)

Available Part Numbers

• 20-0700 - Nissan / Walbro GSS342 / AEM 50-1200
• 20-0701 - Nissan / Walbro F90000267/274/285/295 / E5LM

Why Radium Engineering?

• ✅ Manufactured in the USA to motorsport-grade tolerances
• ✅ CNC-machined billet aluminium components for precision fit and long-term durability
• ✅ Trusted by tuners and race teams running high-power builds on E85 and flex fuel
• ✅ Bolt-on fitment — no cutting, drilling, or fabrication required
• ✅ Compatible with E85, pump petrol, methanol, and flex fuel sensor integration