But whether it is an LS, Gen. V LT, Coyote, or Hellcat, these engines have a serious appetite for fuel. Feeding one requires a fuel delivery system than can provide the proper fuel volume and pressure.
Our project vehicle, a 1971 Buick GS convertible, has a Gen. V LT1 crate motor with a D1SC Procharger supercharger kit. Our horsepower goal is around 800 horsepower with an upgraded camshaft and the Procharger running six PSI of boost.
Enter the Aeromotive Dual Phantom In-Tank Fuel Module. It uses two Stealth 340 LPH fuel pumps and can handle engines rated at 2,000 horsepower naturally aspirated and 1,400 horsepower with EFI and boost. That will work nicely for our GS.
We will use the Dual Phantom system with an Aeromotive Fuel Pump Speed Controller (FPSC) that matches the pumps’ duty cycle to engine RPM via a pulse width modulation (PWM) signal. At low demand, the FPSC slows the fuel pump down, reducing the chance of suction side cavitation and vapor lock. When demand increases, the FPSC returns the fuel pump to 100% duty cycle for maximum flow.
For our GS, one pump will feed the LT1’s main fuel system. The second pump will feed fuel to a second set of injectors in the intake manifold once we get over the 750 horsepower mark, which is the limit of the factory direct-injection injectors.
If you use a returnless fuel system like we are, the FPSC controller can cause issues. When the controlled pump suddenly shuts down, it can actually spin backwards as there is no return line to bleed off the pressure. To keep this from happening, we drilled a 1/32 inch hole in each of the two plugs in the pump pressure port on the module hat. These holes bleed off the pressure should the pump suddenly shut down.
How to Install an Aeromotive Dual Phantom In-Tank Pump
Installing the Aeromotive Dual Phantom In-Tank pump assembly is very straightforward. Doing the install with the tank on a work bench is about a two hour job. The kit comes with a drill jig and the correct drill bit for the module mounting ring. You’ll need a 3-1/4 inch hole saw, a drill, a shop vac to collect the metal shavings, and basic hand tools. A die-grinder, rotary tool, or file is recommended to widen the hole to get the module into the tank and clean up the edges after drilling.
The Phantom systems come with a foam baffle to ensure the pumps are always covered with fuel. The foam is cut to match the depth of the tank plus an additional one inch of clearance. In our case, that is eight inches. The baffle for the dual Phantom unit is larger than the one for the single pump kit, but it will fit through the same diameter hole. The drill jig also serves as a guide to help facilitate the installation of the baffle.
We recommend filling the tank when fuel level goes below the quarter-full mark. In-tank pumps require fuel to stay cool, and running less than quarter-tank will lead to premature failure.
As far as plumbing is concerned, the Dual Phantom system has two output ports, one vent port, and one return port. These are -6 AN O-ring ports that require specific O-ring fittings. DO NOT use standard -6 AN fittings or you’ll have big leaks!
If you use the Aeromotive FSPC control module, the pumps are wired directly to it as the module controls amperage and voltage. Otherwise, the two pumps need separate relays and fuse protection. Each pump pulls about 13 amps at 40 PSI, so a minimum of a 20 amp fuse and 12 gauge wire is required.