Several years ago, Aeromotive, Inc developed its product line of quality reproduction fuel tanks as direct replacements for many muscle cars and street machines. These Stealth fuel tanks included Aeromotive’s in-tank fuel pumps as part of their assemblies to benefit performance EFI and carbureted fuel systems.
These pump and tank combinations became very popular as an opportunity to obtain an OEM-style replacement tank augmented with various Aeromotive in-tank performance fuel pumps. The tank benefits included proper venting, tank baffling, and kept the new pump designs properly submerged in fuel to cure problems such as vapor-lock and cavitation.
Today, Aeromotive’s fuel tank/pump applications have graduated into pure motorsports aluminum cells combined with new brushless fuel pump designs that can feed the horsepower demands upwards of 2,300-carbureted horsepower.
“Brushless fuel pumps and our new brushless gear pumps are a new technology providing many advantages compared to brushed electric motor pumps,” Jeff Stacy, Vice President of Aeromotive Inc. said. “At 75-80 psi of fuel pressure, a 5-gallon per minute pump with a brushless motor will draw 20- to 22-amps less current compared to some other brush motor pumps.”
Brushless Motor Technology Explained
In a simplified explanation; a standard DC electric motor utilizes carbon brushes to charge electromagnets on a shaft that is surrounded by a case of magnets. A “brushless” motor is basically flipped inside out, with the magnets on the spinning armature, and the DC powered electromagnets are on the outer stator.
Since the electricity is fed to the electromagnets on the case, there is no need for carbon brushes to make contact with the spinning armature. Special electronic circuitry is needed to “flip” the polarity of the electricity, which causes the armature to rotate. It is the advent of these electronic controls that allows brushless motors to be proven for use in everything from cordless drills to racing fuel pumps. The brushless technology offers a leap in not only efficiency but also eliminates the sparking of the carbon brush contacts within a volatile situation such as fuel pumps.
“When people ask us about the advantages of brushless, my response is to explain our controller system used in a brushless motor,” Stacy explained. “The controller not only excites the motor to rotate in the proper direction, but it also has other distinct advantages where brush motors fall off.” Stacy continued, “When you start applying fuel pressure downstream, obviously that creates resistance, and a brushed pump motor wants to slow down. Our brushless motor controller senses that and advances the timing to compensate and hold the same pump RPM at any pressure.”
Upgrading Our Project Camaro
Our ’68 is aptly called Project Rover, as in “teaching an old dog new tricks.” What was an old-school Texas Super Stocker is slowly going through a transformation by replacing the old with new technology. For the number of passes we made on the car prior doing the total rebuild, the Holley Dominator carburetor, old “blue” fuel pump, and small fuel line was obviously starving our well-built big-block, even on the 1/8-mile.
The new fuel cell will now feed a recirculating fuel system comprised of Fragola Performance Systems PTFE-lined -10AN fuel hose. The top of our 489 cubic-inch Chevy is a Fuel Air Spark Technology (FAST) EZ-EFI 2.0 fuel injection system, another jump in technology for the old Rover.
With the entire line of Aeromotive fuel pumps now designed for extended service life in a methanol or ethanol fuel environment, the Camaro’s new fuel system is a prime fit, as we will be using VP Racing Fuels C85-ethanol as our racing fuel.
Our Aeromotive fuel cell retrofit included stripping the Camaro’s trunk area and fabricating a pocket for the new 12- x 12- x 10-inch cell to sit inside. This fabrication is well worth the effort compared to merely strapping any cell on top of the floor pan. It afforded us much more room in our limited first-gen Camaro space with the large wheel tubs.
The lower amp draw by these pumps is absolutely nuts. Some early generation fuel pumps could draw over 40-amps when supplying significant pressure and volume demands. Our new brushless motors draw approximately half of that amperage while also running cooler and with greater reliability. – Jeff Stacy
The pocket was far easier to fabricate due to the absence of a bottom sump fitting to feed an external fuel pump. We factored in approximately an extra 1/4-inch of space so we could line the aluminum tank walls with a thin membrane of rubber sheeting to protect it from any wear.
The brushless Stealth cell tank we chose is constructed of heavy wall aluminum with quality TIG welds for the cell and all fittings. The cell is equipped with the A1000 brushless stealth fuel pump. There is a large fluted pickup beneath the pump containing an integral 100-micron pre-filter.
Tank And Pump Technology Combined
The 6-gallon tank features aluminum baffling within the cell that keeps the fuel surrounding the fuel pump pickup. A return line fitting also has baffles surrounding an internal return tube that drops the fuel level. These baffles prevent aeration of the fuel returning to the tank, as well as holding the fuel level around the pump pickup.
“Higher horsepower levels plus the wider use of methanol- and ethanol-based fuels have increased the demands for more fuel delivery capabilities,” Stacy describes. “Brushless motor pump technology combined with our proven pump mechanisms has achieved more consistent fuel flow curves.”
The electronics that control the brushless motor pumps not only operate the pump’s basic functions, they also can advance the timing of the motor’s current to react to increased demands, while a standard brushed motor would fall off in pressure.
“If you review the flow charts on most of our brushless pumps, the pump’s pressure doesn’t fall off against downstream pressure demands like a traditional brushed motor,” Stacy explained. “We program the controller to maintain a set RPM by advancing the electrical current timing only when needed.”
The familiar “workhorse”pump produced by Aeromotive is the A1000 series pump. To illustrate the technology jumps offered by Aeromotive, the A1000 is also offered as the Eliminator model, a 3.5 gear pump, and the 5.0 gear pump. These varied pumps can provide higher and higher pump capacities for anywhere from 1,000- to 3,600-horsepower levels.
Our specific pump could be considered the ultimate brushless pump to handle our E85 fuel big-block bracket racing application. The brushless A1000 has a rated flow capacity of 900-lbs./hr. at 9 psi for carbureted/racing gas engines and 700-lb/hr at 45 psi for electronic fuel injection systems. That equates to supply enough fuel to handle 1,300-flywheel horsepower (FWHP) with a normally-aspirated engine running straight gasoline.
The Aeromotive literature explains factoring in a reduction of 30-percent in horsepower rating when using E85 fuel. This calculates to our new pump capability rated at 910 FWHP — a perfect setup for our engine and demands.
With the same general appearance on the outside as the A1000 and Eliminator pumps, the new brushless motor gear pump models use an internal spur-gear pump mechanism that can deliver higher pressures with minimum flow drop. In racing gas applications, they offer flow rates ranging from 2,400- to 3,600-horsepower, depending on the pump model and the carburetor or EFI system it supplies.
“When you consider some of the amperage requirements from an electronic fuel injection system, ignition, and/or engine control on a racecar electrical system, cutting the electrical drain with a brushless pump can be a huge benefactor,” Stacy explained. “Another new brushless pump we will be releasing will be able to slow the pump down when pressure is not needed.”
Pumps That Change With Pressure Demands
The vast difference between the fuel volume required at idle compared to a wide-open throttle or full load situation demonstrates the need to not run a pump at full capacity at all times. Despite a brushless motor introducing less heat into the fuel, a recirculating fuel system still absorbs engine heat combined with pressure and friction heating of the fuel. These different demand levels are where the advent of a controllable pump that changes output based on up-to-the-second engine demand comes into play.
Stacy finished, “In many dragstrip instances, from the burnout to the time they stage the car, they will recirculate that fuel tank about seven times. If we can make it so it only recirculates it, say, two times, we’ll put a whole lot less heat from pumping and friction in that fuel, and they should make more power. That is just some of the direction we’re going with the brushless technology.”
Our new Aeromotive tank and the brushless pump is now settled within our trunk and plumbed with just three -10AN fittings between our pump and the bypass regulator at the EFI system.
Since a 100-micron pre-filter is designed inside of the fluted pump inlet, we only have one hose fitting at the pump, and two for an Aeromotive 10-micron inline filter. Compared to a bottom-sump tank with two external filters and an external fuel pump, our new fuel system design has eliminated seven hose fitting connections on the pressure side of our recirculating fuel system.
Every now and then, new ideas are transformed into big technology jumps for varied racing components. In many instances, any new product engineering typically comes with a trade-off, but that isn’t the case here. Aeromotive has taken its racing fuel pumps to an entirely new level of reliability with increased flow and pressure outputs and combined it with smaller amperage demands. This long list of benefits with no sacrifices is a fuel system game changer.