Radium Engineering Fuel Cell Surge Tank X - FCST-X | Universal Fitment (20-199X)

Ten years of racing surge tanks, distilled into one lid that drops into a fuel cell.

Radium invented the fuel cell surge tank category in 2013, and the Radium Engineering FCST-X (Fuel Cell Surge Tank-10 Years) is the kaizen result: a complete lift-pump-plus-surge-tank fuel system built into a fuel cell lid assembly, with the surge canister grown from 2.2L to 2.6L, fast pump access through just 9 bolts, an integrated lift handle for servicing, and pump module architecture supporting up to 4 pumps. Versions cover Walbro GSS342/AEM 50-1200/DW440 (20-1990), Bosch BR540/DW400 (20-1991), Walbro F90000267/274/285 (20-1992), and brushless Ti Automotive E5LM (20-1993), sold bare or preassembled with 1, 2, or 3 GSS342 or F90000274 surge pumps plus a matched lift pump. The preferred fuel system architecture of the competition market, ten years on.

Choose Your Version

• Walbro GSS342 / AEM 50-1200 / DW440 family: bare unit 20-1990-00 (no pumps), or preassembled with Walbro GSS342 pumps as 20-1990-01 (1 surge + 1 lift), 20-1990-02 (2 surge + 1 lift), 20-1990-03 (3 surge + 1 lift)
• Bosch BR540 / DW400 family: bare unit 20-1991-00 (no pumps)
• Walbro F90000267/274/285 family: bare unit 20-1992-00 (no pumps), or preassembled with Walbro F90000274 pumps as 20-1992-01 (1 surge + 1 lift), 20-1992-02 (2 surge + 1 lift), 20-1992-03 (3 surge + 1 lift)
• Brushless Ti Automotive E5LM: bare unit 20-1993-00 (no pumps)
• External pump builds: 20-1995-00, with filtered 10AN and 16AN surge tank pickups feeding inline electric or mechanical pumps; internal lift pump still required, sold separately
• Spare drop-in pump modules for pit stop swaps: 20-1996 (GSS342 / AEM / DW440), 20-1997 (BR540 / DW400), 20-1998 (Walbro F9000 series), 20-1999 (Ti E5LM brushless); pumps not included

What You'll Feel

• Zero fuel starvation through sustained cornering, braking, and low fuel levels, the entire reason surge tanks exist
• Pump service measured in minutes: 9 bolts and the integrated lift handle bring the internals out
• Growth headroom to 4 pumps, with swappable pump modules following the build's power curve
• Simplified packaging, since the cell, lift pump, and surge system share one assembly with fewer potential leak points
• Race-ready details: enhanced rollover protection, optimized internal fluid management, and quick-fill fluid control

Features

• 2.6L lightweight surge tank (up from 2.2L) with anti-rotation pump provisions and easily swappable pump modules (sold separately)
• Fast lift and surge pump access via 9 total bolts, with integrated lift handle
• Pump support by version: up to 4 Bosch BR540/DW400, up to 4 brushless DW440, up to 3 Ti E5LM (check valves included on E5LM surge version), up to 3 surge + 1 lift GSS342/AEM 50-1200 or Walbro 450-series
• Compatible with 16AN inlet mechanical pumps and shrouded level sensors
• Fuel level sender block-off standard (SAE senders sold separately); 2AN ORB level switch port preinstalled with plug
• Preassembled variants include new pumps and filters installed; bare variants include components for up to 3 surge pumps

The Details

The architecture is a two-stage system in one housing: a lift pump moves fuel from the cell into the surge canister, and the surge pumps feed the engine from that always-full reservoir, immune to slosh. Pump selection rules from Radium reward attention, since the lift pump always matches the surge pump style except on the E5LM version, which pairs brushless surge pumps with either an E5LM or Walbro 450-series lift pump wearing the 14-0143 filter sock. Two version-specific notes: BR540/DW400 pumps lack built-in check valves so multiple surge pumps must run together rather than staged, and E5LM pumps require their brushless controllers. The 2AN level switch port accepts Radium's fuel level switch for a low-surge warning when canister level drops 20 percent or more. Fuel cell, senders, and pump modules sold separately; verify your pump plan against the version's compatibility list before ordering.

The external pump version, 20-1995-00, replaces the internal surge pumps with filtered pickups: run one or two 10AN pickups, a single 16AN pickup, or a 16AN plus 10AN combination feeding inline electric or mechanical pumps, and when running two pickups an electric pump can prime a mechanical pump for faster starts. Two 80 micron filters cover the 10AN pickups; the 16AN pickup requires an external filter. It still needs an internal lift pump from the Walbro F9000 series, sold separately. The spare drop-in pump modules (20-1996 through 20-1999) are complete lift plus surge pump assemblies that swap into a matching FCST-X in 9 bolts, built for teams that would rather change a module in the pits than diagnose a pump on the clock.

Kit Includes

• 1x FCST-X fuel cell surge tank assembly in the selected pump-compatibility version
• Preassembled variants: 1, 2, or 3 new surge pumps plus matched lift pump with filters installed
• Bare variants: pump provisions and components for up to 3 surge pumps; pumps sold separately
• Fuel level sender block-off plate and 2AN ORB level switch plug preinstalled
• Spare module variants (20-1996 through 20-1999): lift and surge pump module assembly only; pumps and the FCST-X itself sold separately

Applications

• Universal: Radium fuel cells and compatible fuel cell installations for competition and high-performance use
• 20-1990: Walbro GSS342 / AEM 50-1200 / DW440; 20-1991: Bosch BR540 / DW400; 20-1992: Walbro F90000267/274/285; 20-1993: brushless Ti E5LM
• 20-1995-00: external inline electric or mechanical pump builds; 20-1996 through 20-1999: spare drop-in modules matching each pump family
• Pairs with Radium SAE level senders and the fuel level switch/indicator, sold separately

Important Notes

• Bosch BR540 and DW400 pumps have no built-in check valves, so multiple surge pumps must run together rather than staged
• Ti Automotive E5LM pumps require brushless controllers, typically bundled with the pump (see Ti BKS1001)
• The 16AN pickup on 20-1995-00 requires an external filter; the included 80 micron filters cover the 10AN pickups only
• Fuel cell must have the industry standard 6x10 inch 24-bolt top flange with at least 7.7 inches (196mm) internal depth; cells deeper than 12.7 inches (323mm) need Radium lift pump mounts, sold separately