Radium Surge Tank Install Kit for S2000, FST Not Included

Radium Engineering Fuel Surge Tank Install Kit for Honda S2000, FST Sold Separately - Part #20-0094 / #20-0114

An S2000 on track below half a tank will starve the pump in a long right-hander, and the fix is a surge tank. What makes the S2000 install painful is finding a place for it and routing the lines, and that's what these kits solve: Radium's S2000 install kits put the surge tank behind the driver's seat in the trunk on factory threaded bosses, with every hose cut and assembled for the car. The surge tank itself and the pump are sold separately; this is the bracket, plumbing, fittings, and wiring to install one.

What It Is and Why It Works

Both kits mount a Radium single-pump FST in a collision-safe spot behind the left seat using existing bosses, no drilling, on an aluminum bracket with rubber isolators so the pump doesn't drone through the tub. Four preassembled 6AN PTFE hoses with anodized hose ends are cut to length for the car; PTFE doesn't permeate, so the trunk won't smell like fuel, and it's happy in E85. AN and OEM-style adapters connect to the factory lines, and the wiring components with a weatherproof relay and fuse and Raychem splices go together without soldering. The two kits differ because the cars do. The 2000-2005 AP1 has a return-style fuel system, so the 20-0094 kit pairs with the standard Radium FST and a 39mm pump or a Bosch 044. The 2006-2009 AP2 is returnless with no low-pressure return line, so the 20-0114 kit is built around Radium's FST-R, which has an integrated regulator, and includes a billet barb adapter that routes the surge tank's return into the main tank through the filler hose. Neither kit works with the multi-pump MPFST.

Specs

Available Options

Fitment

The split is by fuel system, not chassis: 2004-2005 cars are AP2 but still return-style, so they take the 20-0094 kit.

What to Know Before You Buy

Order three things: this kit, the matching Radium FST (standard for 00-05, FST-R for 06-09), and a pump. Radium sells the FST with a Walbro GSS342, a Walbro F90000274, or an AEM 50-1200 already installed, and the tank alone if you have a pump. The S2000 is a small, quiet car, so pick the pump for the power you need and no more; a 450 in the trunk of an S2000 is audible at idle. On the 06-09 kit, leaving the FST-R's regulator barb unreferenced holds factory fuel pressure, which is what a stock ECU expects. Budget an afternoon; the wiring is 30 minutes and the hoses are pre-made, but getting the filler-hose barb in on the 06-09 is the fiddly part.