One Question: Talking Brushless Gear Fuel Pumps With Aeromotive’s Brett Clow

It’s relatively rare that revolutionary products are developed for the street market, as technology typically trickles down from the racing side into the enthusiast world. In this case, the fine folks at Aeromotive Fuel Systems saw an opportunity to incorporate technology that’s more efficient and offers far greater performance potential than it previously offered.

The company recently released its new 3.5 and 5.0 Brushless Gear fuel pumps, and I wondered what the difference was between these pumps and a typical electric fuel pump. So I went straight to the source—cornering Aeromotive’s Tech Director, Brett Clow—to get the down-and-dirty details of why Aeromotive is using the brushless configuration, and what makes it better.

The new pumps utilize electric motors tailored specifically toward these high-powered street car applications. The design uses similar elements to the company’s mechanical spur gear race pumps. If they live up to their promise—and I have no doubt they will—then we’ll be ushering in a new order of high-powered street cars with better performance than ever before.

Don’t miss the bonus content at the end of the article on Aeromotive’s all-new 7 gpm and 10gpm Brushless Gear pumps, released today at the PRI Show in Indianapolis!

What’s the difference between brush-style and brushless fuel pumps, and what does this mean for the enthusiast when selecting a pump to power their engine?

Brett Clow, Aeromotive Fuel Systems: Conventional brush-style motors have been with us coming up on 200 years with the first running prototypes revealed in 1821. The first DC motors, like those used in automobiles, came into being in the 1830s. Today’s brush-style DC electric motors are proven, affordable, reasonably efficient and durable pieces of equipment, but with certain liabilities that ultimately led to the development of new DC motor technology to address these concerns namely being weight, efficiency (current draw) and environmental contamination (brush and commutator particulate debris from friction).

Brushless DC motors resemble a 3-phase AC motor with a motor controller that takes a DC input and outputs a processor-controlled AC signal to fire and run the motor. With no friction between the brush and commutator, contamination and frictional losses are eliminated and reduced, respectively. The brushless motor assembly is also lighter, generating torque with less mass (fewer copper windings and much smaller field magnets). Efficiency is significantly increased with much as 50 percent less current draw for the same flow output, and thanks to the processor-controlled firing, can develop a flatter torque curve against load (maintain a flatter pump RPM as pressure rises) delivering more flow at higher pressures than a brush motor-driven pump.

We have excellent TVS (True Variable Speed) performance with the 3.5 and the 5.0 Brushless Gear Pumps, and we’re in the process of finalizing the TVS controller configuration for the roller vane style A1000 and Eliminator pumps. The final execution is intended to be the same for both types of pumps, where a third wire input on the motor controller looks for an analog reference voltage between 0-5 VDC.

The reference voltage low threshold (floor) on the sensor wire is 0.5 VDC, where the minimum pump speed is achieved and held, and as voltage goes above 0.5 VDC up to 3.8 VDC, the pump speed increases progressively. The reference voltage high threshold (ceiling) is 3.8 VDC, where the maximum pump speed is achieved and held at or above this voltage, which would put the fuel pump at full speed between 70–85% TPS opening, depending on TPS calibration.

The idea with this approach was to simplify controlling fuel pump speed using an available output like that of the TPS sensor. This eliminates any additional control components and keeps the cost down and the implementation clean and simple. There are a couple of ways to wire the TVS controller, including simply switching 12-VDC to the input wire to go from slow to full speed using a programmable output on the ECU or a WOT switch, or even manually.

In summary, a brushless electric fuel pump, combined with an efficient Aeromotive pumping mechanism, will weigh less, flow more, draw less current, run cleaner and last longer than an equivalent brush-style motor-driven pump.

I thought the great information provided above by Brett would be the end of our One Question segment this month. Then I caught wind of Aeromotive’s all-new 10 gpm and 7 gpm Brushless Gear Pumps, released to the public just moments ago at the Performance Racing Industry show. I had early access last week to chat about the pump with Aeromotive Vice President Jeff Stacy, who was kind enough to fill me on regarding the details of this revolutionary piece.

For reference’s sake, let’s get the cold, hard facts out of the way right at the beginning. The 10-gallon-per-minute brushless pump will support up to 4,900 horsepower at the flywheel in a forced induction gasoline application, and up to 3,430 horsepower in an E85 application. The 7 gpm pump will cover 3,400 horsepower on gas and 2,380 horsepower on E85.

Single, electric, in-tank fuel pumps with this sort of capability didn’t exist—until now—and it’s been through Aeromotive’s wringer in terms of engineering and prototype testing to arrive at this destination.

Front Street:  Jeff—what’s the deal with these new pumps?

Jeff Stacy, Aeromotive Fuel Systems: The 7 gpm pump and 10 gpm pumps utilize the same 1-inch gear—which is physically larger than the smaller pumps—and the two new pumps are the same length. The major difference between the two is in the motor size.

The cool thing about a brushless electric motor is that it’s designed to run at a certain RPM. When you load that motor, and it slows down, it will start to advance the timing of the electric motor to try to achieve that RPM again. The technology is not as susceptible, like a brushed motor, to slowing down at high pressure. Even though we’re moving twice as much fuel, the electric motor doesn’t care. We can use a much smaller electric motor because of the brushless technology.

Currently, these pumps will fit into any of the fuel cells we manufacture. We will also have an external version, so if you have some other external pump on your car, you can unbolt it and put the 7 or 10 gpm brushless pump into its place. In the future, we will be looking at mounting these into stock gas tanks: vehicles like the Corvette, Mustang, Challenger, Camaro, and Raptor. We’ve used the 3.5 gpm pump in several pickup trucks, and it worked like a champ, so we see no reason not to put this big brother pump into those stock gas tanks. We’ll build an adapter that replaces the stock lock ring, add our Phantom foam and bladder system as our bucket, and then insert the 5, 7, or 10 gpm pumps into that hole. The bladder will work as the reservoir, and the fuel returns to the reservoir to keep the inlet of the pump covered, always.

All of the 7 and 10 gpm pumps use the same True Variable Speed controllers as the smaller 3.5 and 5.0 gpm pumps and use a 0-5 volt signal and wire it up to the pump, so when you’re sitting at a stoplight and idling, it will only be pumping, say, 2 gallons per minute. As you ease into the throttle, it will apply full power to the pump as you get over 3.7 VDC. Up to 3.7 VDC, the pump is controlled with pulse width modulation to slow it down as maximum fueling is not necessary, and once we get over 3.7 VDC at the signal, we apply a constant 13.5 or 14 VDC to the pump, and the pulse width modulation is turned off.

We’re going to make it readily available for a lot of applications. The only thing we need to change to make it fit is the depth of the pickup to reach the bottom of the tank. We’re also going to have to use a perpendicular outlet in for some of those stock tanks that are jammed up against the floorboard.

Thanks to Brett and Jeff for taking time out of their busy schedules to talk with us! Check out previous installments of One Question content right here.

Product Photos: Aeromotive