Radium Engineering FHST Extension Add-on Audi R8 Type-4S Lamborghini Huracan

The Radium Engineering FHST Extension Add-On for Audi R8 Type 4S and Lamborghini Huracan increases the usable capacity and depth of Radiums 20-0860 Fuel Hanger Surge Tank for vehicles with the deeper Gen 2 fuel tank. This is not a hose fitting or plumbing adapter. It physically extends the FHST canister so the surge tank reaches farther toward the bottom of the fuel tank, helping make more fuel available to the aftermarket pump.

The extension adds approximately 0.2 liter / 7 ounces of fuel capacity and makes the FHST canister 1.5 inches / 39mm deeper. Radium positions the extension section between the existing canister and bottom cap, while included longer internal tubing and a longer fuel-pump bracket keep the pump inlet properly positioned at the bottom of the extended surge tank. A stainless-steel bracket is also included to relocate the factory venturi jet pump for the additional clearance required by the deeper assembly.

Radium specifically recommends this extension for the second-generation Audi R8 Type 4S and Lamborghini Huracan because of their deeper fuel tanks. It is not compatible with the first-generation Audi R8 Type 42 or Lamborghini Gallardo, which use shallower tanks and do not require the additional FHST depth.