Radium Fuel Surge Tank Install Kit | 1999-2006 BMW E46 Excluding Convertible (20-0974)

A surge tank solves starvation. Mounting one properly in an E46 is the part nobody warns you about.

The Radium Engineering fuel surge tank install kit for the BMW E46 supplies everything needed to fit a Radium fuel surge tank to the E46 chassis, and it does the packaging work for you. The tank locates in a collision-safe area of the trunk behind the rear seat on a bolt-on aluminum bracket with rubber vibration isolators, which keeps surge pump noise out of the cabin. The PTFE hoses come cut to length and preassembled, and they meet at a junction in the trunk through an anodized bulkhead plate with four bulkhead fittings, so the install looks finished rather than improvised.

What You'll Feel

• A surge tank mounted where a collision will not find it, not strapped into the spare wheel well
• Pump noise damped by vibration isolators rather than transmitted through the body
• Preassembled PTFE hoses cut to length instead of measured and built on the car
• A tidy bulkhead pass-through in the trunk instead of hoses threaded through a grommet
• A modular electrical install using a proper connector rather than spliced wiring

Features

• Aluminum mounting bracket with rubber vibration isolators
• Preassembled 3/8in PTFE hoses, cut to length
• Anodized aluminum bulkhead plate with AN bulkhead and adapter fittings
• 40 amp relay and 25 amp fuse, weatherproof
• Delphi Weather-Pack connector for fuel pump trigger activation
• Stainless steel hardware

The Details

This is the install kit only. The surge tank and its pump are separate purchases; the store carries the Radium 20-0960 single pump fuel surge tank, which this kit is built around. The Delphi connector on the trigger circuit keeps the system modular, so the tank can be removed or serviced without cutting into the car's harness.

One sizing rule matters before you order pumps. The main tank's pump is what keeps the surge tank full, so it needs to flow roughly 40 to 50 percent of whatever the surge tank pump flows. Fit a large surge pump behind a stock in-tank pump and the surge tank will run dry under sustained demand, which defeats the point. Depending on the pump you choose, a drop-in upgrade for the main tank may be required.

Kit Includes

• Preassembled 3/8in PTFE hoses
• Aluminum mounting bracket with vibration isolators
• Anodized aluminum bulkhead plate
• AN bulkhead and adapter fittings
• 40 amp relay and 25 amp fuse
• Stainless steel hardware
• NOT included: fuel surge tank, surge tank fuel pump, and any main tank pump upgrade

Applications

• 1999-2006 BMW E46 3-series
• 1999-2006 BMW E46 M3

Important Notes

• NOT compatible with the E46 convertible
• Requires a Radium fuel surge tank and a surge tank fuel pump, both sold separately
• The main tank pump must flow roughly 40 to 50 percent of the surge tank pump's flow rate