Building a fuel system is a balancing act between supply and demand, with the demand coming from what your engine needs to run correctly, and the supply, of course, from the fuel pump you’ve chosen to use. Fuelab’s new 47403 H/E Series Fuel Pump is the solution to your high-performance needs with its high-efficiency design and brushless motor technology. In this article, we’ll take a look at what makes this pump more efficient and able to work with a variety of applications.

For over a decade, Fuelab has been bringing the high-performance aftermarket cutting-edge fuel system products that have been used in street cars all the way up to full-blown racing machines. Their brushless fuel pumps, starting with the Prodigy, spawned new technical innovations that made their way into other products, like their electronic fuel pressure regulators. Now, the 47403 brushless motor fuel pump is the next step in fuel system technology for Fuelab and fuel systems.

Fuelab spent a considerable amount of time developing this new pump to make sure it would fit the mold of the vision they laid out. Fuelab’s Chief Engineer, Rob Scharfenberg, sheds some light into the process that was used to develop the 47403 pump.


“We continuously look into other pumping methods and technologies to find where improvements can be made. Anytime we can either get improved performance or the customer’s costs down, we take advantage of it. When we saw this technology, we knew right away that we wanted to be a part of it and use it on this pump. It took us over a year to implement and test everything with the 47403 during the development phase.”

The 47403 fuel pump can be plumbed into a system in multiple ways.

The Makeup Of The 47403 H/E Fuel Pump

We continuously look into other pumping methods and technologies to find where improvements can be made. - Rob Scharfenberg, Fuelab

To create a truly innovative pump, Fuelab decided to start with a totally blank slate when the design process began for the 47403. To start, Fuelab made the pump entirely out of high-quality billet aluminium to ensure its strength and ability to resist the corrosive nature of different racing fuels. The use of the billet aluminum also helps to keep the weight down to a scant three pounds, allowing the pump to be mounted in more locations. Inside the the 47403 is a highly reliable and powerful DC brushless motor that’s able to support over 1,250 horsepower. This motor is highly advanced so it doesn’t require a speed controller and is able to operate at a continuous speed.

The 47403 has a new twin screw rotor pumping mechanism that allows the pump to be extremely efficient, so it draws less current and has a lower noise level than most pumps. Fuelab also wanted to make sure the 47403 wouldn’t leave a racer stranded in the lanes, so they made sure the pump had excellent priming capabilities and a higher level of resistance to cavitation while in operation.

In this cutaway rendering, you can see just how packed everything is inside the fuel pump.


To make the 47403 work with fuels like gasoline, diesel, methanol, and ethanol, Fuelab stepped up the pump’s ability to perform with a 125 psi maximum operating pressure. At 13.5 volts, the 47403 can flow 500 lph of fuel at 45 psi. With these kinds of flow numbers, the 47403 can be used with most fuel injection applications and with a power adder, as well. Even with such a high rate of flow, the 47403 has a noise level that is a fraction of what their other current systems put out.

Scharfenberg is quick to point out that the new pump had some other surprises that became apparent during their initial development. “We were so impressed with the performance that we decided to not integrate the speed control function into the first production, as the current draw is nearly as low as a typical OEM pump, despite having an over 1,250 horsepower support rating. Compared to other pumps, we have raised the overall performance efficiency (electrical power in versus fluid power out) from about 25 to about 45 percent, too.”

The 47403's sizing allows it to be easly mounted almost anywhere in a car.

What makes the 47403 different than other fuel pumps in Fuelab’s current lineup is its versatility. Even though the pump is designed to work with EFI applications, it can be used on virtually anything, from high-performance diesel motors, to anything with a carburetor. “While we will rely on our current vane design for the higher flow capacity, the 47403’s superior performance has the potential to replace our 414xx Series Pumps in the future,” Scharfenberg says.


Design And Efficiency Of The 47403 Fuel Pump

The hallmark of a good fuel pump and system is its ability to be efficient at getting liquid from the tank to the engine. Fuelab decided to use a twin-screw design in the 47403 pump to amp up how efficient it is. The twin screw design functions like a multi-stage pump system inside the 47403 fuel pump. This multi-stage system brings down the amount of internal leakage, or fuel that back-flows, rather than gets pumped, and that’s where some of the biggest efficiency gains are for the 47403.

When we saw this technology, we knew right away that we wanted to be a part of it and use it on this pump. -Rob Scharfenberg, Fuelab

“The special shape of the two screws folds in to capture a small amount of fuel to move between the screws. The ‘multi-stage’ aspect comes into play, as there are as many as five complete chambers being moved with fuel inside and that has an effect of having up to five stages. It can almost be thought of as a three-dimensional representation of a classic spur gear pump design. In addition to the multi-stage effect, the screw pump also allows for higher motor speeds with less required torque. It then allows us to use more hydrodynamic motor designs for less fluid drag. This technology has been around for a while in industrial high-flow applications, however, the technology to machine or grind such a profile has been prohibitively expensive until recently,” Scharfenberg explains.

Here is how the multi-stage system works with the screw inside the pump.

A problem that can occur with pumps that move a large volume of fuel is cavitation or “vapor-lock.” This is when a restriction or heat in the pump cause the fuel to vaporize or boil inside the pump itself. This will damage the pump and possibly the engine, because it becomes starved for fuel. With the 47403, Fuelab took some extra measures in the twin-screw design to help limit this.

“The ends of the screws are directed more precisely into the incoming flow path. Our vane design tends to route fuel around the passages, thus creating slight pressure drops. The inherent nature of the smooth ‘folding’ action of the screws helps reduce high fuel velocity changes and limiting the buildup of heat,” Scharfenberg says.


The motivating force behind the twin-screw design inside the 47403 pump is the brushless electric motor technology. This type of motor provides the backbone of the pump and plays a critical role in why it performs so well in so many different applications. Compared to the standard brushed motors, the brushless units help to make the pump powerful enough to support over 1,000 horsepower while still being as efficient as possible.

Brushless Motors In Fuel Pumps

Brushless motors in fuel pumps like the 47403 have some great advantages, according to Scharfenberg.

“Using brushless motors can combat the highly oxygenated race fuels that can corrode commutators of brushed motors, causing failures. Brushless motors use less current, as the electronics used to operate them have less electrical losses than brushes and can direct that power as needed more efficiently than a mechanical ‘on-off’ switch that comprises brushed motor designs. Brushless motors typically use much higher magnetic flux magnets such as Neodymium instead of cheaper and less powerful ceramic-based magnets. This enables a much higher power capability in a smaller package. Because of the built-in electronics, an input signal can be used from an external source such as an electronic regulator or the vehicle’s ECU to control the speed of the pump’s motor directly allowing the reduction of speed during low engine demand to lower the current draw.”

According to Scharfenberg, there are three big advantages that brushless technology brings to the table when it comes to a fuel pump.

“These motors use Neodymium permanent magnets instead of typical ceramic magnets and allow for a more powerful, compact, and lighter design. The efficiencies are also improved over brushed motor designs, especially when brushes and commutators are designed to be compatible with fuels in wet motor designs. Finally, the brushless motors provide an improved oxygenated fuel compatibility, including E85 and methanol, as well as allowing for a wet-motor design that is compatible with diesel fuels.”

To make the brushless motor system inside the 47403 function properly, Fuelab used their digital pump technology to help control them. This technology is the core of all their electronic controller platforms and are part of the electronics needed to operate a DC brushless motor. “While we have been making our own electronics over the years, we have been able to implement design improvements as well as an entire new generation of controllers. We are continuously working on new designs for these sub-systems, as well, bringing improvements to reliability and function to help the motors be more efficient,” Scharfenberg says.

Keeping the electrical current draw to a minimum is important for a fuel system that has a pump that’s moving a large volume of fuel, and that’s another reason why an efficient fuel pump is so important. Understanding that current will get changed to heat that will actually warm the fuel in the system, along with the other parts of the fuel system or rails, Fuelab paid close attention to how much current the 47403 used.

“The less amount of electrical current draw that the fuel system uses to accomplish the requirements, the less amount of heating of the fuel system is done. When the fuel system gets too hot or if the inlet to the pump is too restricted, then the fuel can boil at the pump, not just to the point of losing pressure, but will also damage pump components as well,” Scharfenberg explains.

Fuelab’s 47403 H/E Series Fuel Pump combines cutting edge technology with a well-thought-out design to create a robust fuel pump. By looking at what makes a fuel pump great as a whole, Fuelab was able to design a pump that can be used in multiple applications. The 47403 brings to the table everything needed to be the centerpiece of any high-performance fuel system that a racer can create.