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How to Install an Aeromotive 325 Stealth Fuel Pump Into a New Edge Mustang
Fuel in a Flash
Forced induction is a double-edged sword for performance. The bang-for the-buck is fantastic, especially on modular engine Mustangs that respond very well to boost, but it’s also a good idea to upgrade items where necessary. In this case we are looking to turn up the boost in the near future, so we wanted to make sure that plenty of fuel was supplied to safely bump up the power.
We say “safely” because ramming more air into an internal combustion engine than it can ingest on its own accord requires a large compensation in the landscape of the tune in the ECU. The parameters have to be slid around a bit to keep the engine within a range that makes power and also in the air/fuel ratio range to keep detonation away. If you increase the air coming in, fuel and spark have to rise to meet the challenge. We have got the air on our 1999 GT project car, and the ignition is up to par, and preparing the fuel system portion is part of the total equation.
It is worth noting that in 1999, Ford switched the Mustang fuel system to a returnless style, which supplies pressure through a pulse-width modulated (PWM) setup; not all aftermarket pumps work well with this design, and some work better than others.
As is so often the case, Aeromotive has exactly what we need to make sure we never encounter fuel starvation issues. The new 325 pump in the company’s Stealth series is a compact body design that not only flows more than 325 lph at 40 psi (enough to support 700 hp in a blown application like ours) but also works with many factory hanger assemblies and fuel lines. And, it is PWM friendly. In short, it gives us the fuel we need to make power without being a pain to install.
1. Getting the rear-mounted fuel tank out of all Fox, SN95, and New Edge Mustangs is fairly easy, even without the added ease of a lift. Try to run your Mustang as low on fuel as you can before attempting this. Once the electric plugs are pulled, the fuel line needs to be disconnected as well. These use a special quick-disconnect tool that you can rent from a parts store.
2. To get to the pump, the hat that seals the hangar and pump assembly to the tank needs to be pulled.
3. The tank seal portion of the assembly will come off separately. After lifting it, grab the wires and convoluted hose and guide it out.
4. With the wires and hose pulled out a bit, grab the internal fuel pump sump and lift it out.
5. To get to the pump, we need to disassemble the internal sump. The lid will snap off, but be cautious not to apply too much force and crack it.
6. Here is the Aeromotive 325 next to the factory pump. As you can see, they are very close in overall size and configuration, which is why this swap works so well. The difference in power-supporting capability is night and day, though.
7. Since the Aeromotive pump can flow so much fuel, we actually need to create a better way for unused fuel to exit the sump. A 3/8-inch hole drilled about half an inch above the floor of the sump will be the new drain back.
8. We’re leaving all the stock wiring on the hat, but we had to clip the stock fuel pump plug since it will not match the Aeromotive 325.
9. The pink and black wire is the positive, and the black is negative. Make sure the crimps are solid, and no bare wires are showing that could possibly contact metal.
10. Much like the stock Ford pump, the Aeromotive pump has a sock-style filter that attaches at the inlet to keep any potential particles from entering it or the engine.
11. With the 325 installed, the internal sump can be reassembled just like factory and dropped back into the tank.
12. All it took was a couple of hours’ worth of work and we are ready for the next addition to our New Edge. Stay tuned as we get ready to really turn up the wick.