The Radium Fuel Hanger Surge Tank (FHST) is a revolutionary in-tank solution to eliminate fuel starvation during high-performance driving while also providing the ability to upgrade to one or two high-flow aftermarket fuel pumps. Designed specifically for BMW platforms, the FHST installs inside the fuel tank opposite the OEM fuel pump and is fully compatible with gasoline and E85. No permanent modifications are required.

How It Works

The OEM saddlebag fuel tank design often suffers fuel slosh under high lateral G-forces. The FHST prevents starvation by drawing fuel from three sources:

• The OEM electric lift pump
• The fuel pressure regulator (FPR)
• An integrated one-way fill valve

Regulator Technology

Equipped with RA-series regulators, the FHST offers tool-less 1:1 fuel pressure adjustment with tactile detents, a swiveling vacuum reference port, and four interchangeable fittings:

• 3/16" barbed fitting
• 3AN male adapter
• Push-to-connect for 1/4" OD tubing
• Vacuum plug for constant fuel pressure setups

Electrical & Construction

• Custom stainless electrical studs rated for high current
• ETFE-insulated in-tank wiring, fuel and ethanol resistant
• Non-conductive acorn nuts to prevent short circuits
• Relay, fuse, and wiring kit included for one pump (additional kit required for dual setups)
• Anodized aluminum canister, fittings, and stainless hardware

Key Benefits

• Drop-in OEM replacement—no permanent modifications
• Supports one or two surge pumps
• Protects against fuel starvation during hard cornering
• Compatible with various high-performance fuel pumps
• Gasoline and ethanol (E85) compliant
• Relay(s), fuse(s), and electrical hardware included

Part Numbers

• 20-1970 FHST: Fits Walbro GSS342, AEM 50-1200
• 20-1972 FHST: Fits Walbro F90000267/274/285

Both part numbers are shipped partially assembled and include all components required to install one or two pumps (pumps sold separately).