Radium Engineering FHST Add-On – Nissan S14, S15, R33, R34 (All Models)

The Radium FHST (fuel hanger surge tank) add-on is a modular in-tank solution designed to eliminate fuel starvation in late model Nissans with saddle-bag style fuel tanks. Intended to pair with an existing Radium fuel pump hanger, this kit converts the system into a fully functional in-tank surge tank setup.

The surge tank is supplied by a dedicated lift pump (located in the OEM position) and supports one or two high-flow fuel pumps, including brushless options, to feed the engine. No permanent modifications are required. Compatible with all fuel types including E85, methanol, and petrol.

How it Works
The surge tank remains full via four fuel supply sources:

1. Lift pump from the OEM hanger

2. Return fuel from the regulator

3. Integrated venturi jet pump siphon

4. 355LPH one-way fill valve

Pump Compatibility
The FHST add-on supports a variety of fuel pumps depending on the selected version:

20-0701 (Brushless-Compatible)

• Walbro F90000267 / F90000274 / F90000285

• Walbro F90000295

• Ti Automotive E5LM (brushless)

20-0700 (Brushed-Compatible)

• Walbro GSS342 255lph

• AEM 50-1200

• AEM 50-1230 / 50-1235

Note: Pumps marked with "+" do not include a check valve. If this is required, use Radium 20-1534.

Electrical
A full wiring harness is included to power one FHST pump (relay, fuse, terminals, and wiring). To power a second surge tank pump, an additional wiring kit (Radium 17-0031) is recommended. The OEM wiring is sufficient for the lift pump due to low pressure operation.

Features

• Simple integration with Radium fuel hangers

• Fuel starvation protection

• Drop-in installation, no cutting or modifications

• Brushless fuel pump compatibility

• Anodised aluminium construction

• High-current electrical hardware

• Stainless steel mounting hardware and clamps

• Compatible with petrol, ethanol, and methanol