Mustang EFI enthusiasts have been upgrading their fuel systems since the first throttle body and set of headers were installed on a 1986 Mustang. And Aeromotive has been right there the entire time, supplying racers and hot rodders with intuitive and well made fuel regulators, external fuel pumps, and even complete fuel systems. However, the brains over at Aeromotive have released an entirely new type of fuel system that brings performance and simplicity to an entire different level. It’s called the Aeromotive “Stealth” – and it’s going to change how you think about “bolt-on” aftermarket fuel systems forever.
When we first learned about the Aeromotive Stealth, we already had some fuel system needs for our 1986 Mustang Coupe that we refer to as Project 666. It just so happened that our desires for fueling for 666 matched what the Stealth could offer.
- 800 HP Capable
- Ease of Installation (Meaning no fabrication)
- Ability to use it with EFI or Carb
- No loss in streetability or fuel capacity.
So.. what’s the Aeromotive Stealth….? Here is the quick rundown on what the Stealth is all about.
Aeromotive Stealth Technology 101
For years Aeromotive made aftermarket fuel pumps that has to be mounted externally on your vehicle. That made either having a vehicle that Aeromotive already made brackets for, or fabrication. It means lots of plumbing and connections.
Aeromotive’s concept with the Stealth was to follow the lead from the OEMs when it came to fuel pump location. The Aeromotive Stealth is a completely self-contained system where the fuel pump and the fuel filter are located INSIDE the actual sump of the tank, which Aeromotive provides.
The Stealth System is available in several variations. You can buy just the sump kits, whether you need a sump only that you can weld into the OE tank on your Mustang, or brand new tank with the sump already welded into it for a bolt in job. The pre-welded tank is currently only available for the Fox Body Mustangs, but more applications are in the works. For our project, we went with the pre-welded tank for the ease of install and that fact that is was a brand new tank that would replace the worn out gas box we had in the car.
Other variations and options include adding fuel lines, regulators, and fuel rail or fuel line kits. So Aeromotive offers either “soup to nuts” systems or just the Stealth box kits.
The Stealth is the combination of an OE fuel tank design and a sump that not only holds more fuel, but houses the fuel pump and fuel filter inside it. First, when you look at the tank, right away you can tell something is different. Where the stock tank tucks under the rear of the car, the Stealth drops down 2 inches from the lowest point on the stock tank, 6 inches from the rear of the tank.
This sump provides the ideal location for the fuel pump to pick up fuel on heavy acceleration, but also the optimum gravity pick up point. It’s a win-win solution, and something that was NEVER before possible with aftermarket fueling components.
Inside Aeromotive’s World
To find out why you would want the fuel pump inside your tank, and everything else we wanted to know about the Stealth, we spoke with Aeromotive’s Jesse Powell. He was able to not only guide us to picking to the right options for our project, but give us the back ground on where this system came from – lets start with the history lesson.
“People needed more fuel to power their high horsepower cars,” Powell explains, “You can’t just slap on a bigger fuel pump and think that you are going to be able to pump all the fuel you are going to need.” But that is what so many people do. The problem lies not in the fuel pump, but the rest of their fuel system not being able to support the larger demand for fuel. “You can’t expect a bigger pump to be able to suck through the straw like OE pick up tube. Even if you bump the size of the tube up, that still doesn’t solve the handful of other problems with the stock tank,” says Powell.
And he is right, the OE tank design does not lend it self to stopping things such as fuel slosh, which can starve a pump quickly if the fuel moves away from the pickup tube. Aeromotive wanted to solve this and their first weld-in sump was the solution.
According to Powell, “The sump works as a basket for the fuel. It holds a large amount of fuel right where you want it, the pick up side of the fuel pump.” By combining it with the OE tank you get the best of both worlds. You have a baffled design that will keep plenty of fuel over your pick up, but you still retain the large fuel capacity of the OE tank. This is a major thing for cars that drive on the street and could not live with just a 3-5 gallon fuel cell.
The last unique thing is the mounting of the fuel pump and filter inside the sump, at the bottom on the tank. “Fuel pumps can push through anything, but they are limited on what they can pull through,” said Powell. What that means is errors made on the out side of the pump will not always kill the pump, but if you make a mistake on the supply side of it, watch out. You can easily fry a pump by starving it of fuel causing it to heat up and vapor lock. That’s why Aeromotive designed the Stealth system to house the pump and filter inside the tank, meaning there is nothing to hook up to it except the fuel line going to the engine.
An “inside look” at the internals of the Aeromotive Stealth system. You can see how the fuel pump and filter are connected directly for maximum flow in a small space. Best benefit, you don’t need to go the expense of extra hoses and fittings. This picture is before Aeromotive adds some of their baffling.
Inside the sump, they did more than just bolt the two components in. According to Powell, the team designed and test multiple different configurations to find the one the would work best. With the fuel being forced by gravity to the bottom of the sump, it only makes sense that the pick up was mounted here. The fuel travels through two small holes at the bottom of the fuel filter housing where it passes through the filter before heading around the 180 degree tube and through the fuel pump. This means that the pump is submerged most of the time by the surrounding fuel that is in the tank. The fuel helps to cool the pump, ensuring that heat is never a problem for it. Plus, because the fuel is inside of the tank, the operation is quieter. It is called the “Stealth” after all!
Here’s the Aeromotive Stealth’s baffle. It calms the fuel as it transitions to the bottom of the sump near the pick up. This one sits above the pump and filter to separate the pick up fuel and the fuel being dropped into the sump from the other parts of the tank or the return bung.
Many will assume that because the fuel pump and filter are mounted inside the tank, that changing the pump or filter would be a pain in the first part of assume – not the case at all. In fact we don’t think it could be any easier. Both can be installed with the sump welded to the tank and the tank in the car. On the rear are two ports where each respective component can be installed into. The two holes are different sizes, so there is no installing the fuel pump where the filter goes.
“We played around and tested many different sump designs before going with the design you see on the finished product,” Powell told us, “We went with the current design when we were able to fill the sump with a half gallon of fuel, and turn the entire sump 45 degrees in any direction and still keep the pick up covered with fuel.”
Fuel Pump Choices
Speaking of the pump. Aeromotive gives you two choices for a fuel pump in the Stealth system, the A1000 or the Eliminator. “It really all comes down to the amount of horsepower you are making when you are looking to decide which pump will work best for you,” Powell explained, “Many think that one is our EFI pump and the other is our carburetor pump. The truth is, fuel pumps don’t care what they are pump or where they are pumping. So weather it is gas, diesel or E85 being pumped at 80 psi or 7 psi, it is all the same to the pump. You can use either for EFI or carburetor applications which is why we give you the horsepower rating for both systems on each pump.”
Forced induction also changes the horsepower capacity that the pump can support, but here is the info you need to make your decision.
- Fuel Injected making up to 1300 HP – naturally aspirated
- Fuel Injected making up to 1000 HP – forced-air induction
- Carbureted making up to 1500 HP – naturally aspirated
- Carbureted making up to 1200 HP – forced-air induction
Go with the Eliminator Pump when:
- Fuel Injected making up to 1900 HP – naturally aspirated
- Fuel Injected making up to 1400 HP – forced-air induction
- Carbureted making up to 2300 HP – naturally aspirated
- Carbureted making up to 1700 HP – forced-air induction
The Install: “Stealth” goes from Concept to Reality on 666
Our Project 666 has a 550 hp 408 naturally aspirated Ford small block with a Carb. We ordered up a complete Aeromotive Stealth system with the A1000 pump, Aeromotive Fuel lines and fittings, and a Aeromotive Fuel Line/Rail Kit with integrated Carb-style regulator.
We started in the back of our Fox Body with the tank.
Before we could install the new Stealth tank, we had a few minor things to do to it first. We removed the stock tank to start with.
The return line is moved on the new tank, there is no need for the hole on the top right of the OE tank Aeromotive provides. Thus, Aeromotive includes a cap that will seal this port shut, keeping outside elements out and the fuel inside. If you wish to reuse the fuel level sending unit off the stock tank, this is found in the large component that is removed from the center hole on the top of the stock tank. It is best to remove the stock fuel pump from this as well.
We were not reinstalling the fuel level sender so we just capped this one off as well. Keep in mind because the bottom of the tank is now lower due to the sump, your fuel level gauge will be off. According to Aeromotive when the gauge reads empty, you will still have around one gallon of fuel left in the sump.
Next we pried the stock full filler next off the stock tank and installed it on the Stealth tank in the reverse order of removal. We positioned the new tank under the car and lifted it into position. We bolted the straps back in to hold the tank inside the car while snaking the filler neck back into the side of the tank.
Next we slid the fuel filter and A1000 Pump into the back side of the tank. Thanks to the design on the Mustang, where the tank mounts below the trunk and already hangs a little low, we can always easily get to these when needed.
We then turned out attention to the engine bay of our project. We finished removing all of the remain parts from the stock fuel system and started to assemble the fuel rail on the bench. Assembling the fuel rail took no more than 20 minutes to complete.
We started with attaching the AN fittings to the ends of the rail. Next, we screwed on the fuel pressure regulator onto the end of the fuel rail. According to Powell, “We always recommend installing the regulator on the return side of the system. The fuel pump is more than capable of pushing more than enough fuel to the rail, so we only want to regulate how much it doesn’t need. This keeps the fuel bowls equally pressured for an even, consistent fuel spray.”
The final steps of our install consisted of building the Aeromotive fuel lines, and running them the length of the car. While we were at it, we also installed the Aeromotive Fuel Filter. We found a nice stop to hide it right under the filler neck where we secured it with a few zip-ties.
Instead of just drilling a hole in the fender well where we chose to run the fuel line and sliding the hose through, we installed two bulkhead fittings. This does a few things for us. Number one it helps protect the fuel lines from heat, suspension, and damage. Second, it looks a lot better. And we are ALL about looking better.
Finishing the System: Fuel Lines, Fuel Rails & Regulators
While that may have seemed like a lot of information, that only describes half of the fuel system. To divide our fuel up between the two float bowls we picked up an Aeromotive adjustable fuel rail. This would let us install the kit on not only the current engine in the car, but almost any carburetor we could ever stick in the car. All we would have to do is lengthen or shorten the fuel rail to the exact size needed. “Just like the Stealth Tank, we wanted to design a line of products that would be able to last the life of the car,” Powell said.
We found it easier to install the carburetor-to-fuel rail pieces first. We attached these to the fuel bowls, then screwed on the fuel rail – complete with regulator.
Next up was one of Aeromotive’s fuel pressure regulators. They have over 30 different regulators to choose from, so you are sure to find one that fits what you need for your car. We went with their A1000 Bypass Regulator which has an adjustable base fuel pressure of 3-15 psi.
Those that have this regulator may notice that ours looks a little different. Aeromotive usually equips these with an anodized bottom. We went a different route and ordered the marine version of this same regulator. Internally they are the same, but the marine one is coated all black, mixing perfectly with the stealth look of our system.
That wraps up our install of the Aeromotive Stealth System on Project 666. This system is great for the street enthusiast and sportsman racer – it can supply the big horsepower, is perfectly streetable, and provides superior ease of install. If you are looking for a fuel system that will out last your car, this is the one. If you don’t have a Mustang, Aeromotive is currently in development for other popular car, but they are already Stealth Fuel Cells that can be purchased.
Here is a review of our goals for the fuel system
- Upgrade fuel pump to support up to at least 800 HP Check!
- Ease of Install (Meaning no fabrication) Check!
- Ability to be used with different engines and retain many of the components Check!
- Replace fuel lines Check!
- Not lose fuel tank capacity Check!
Up next for 666, our Fox Body will continue to be under the knife as we finish up the remaining installing and take her our to the track for some real world testing.