FAQ's On Aeromotive Brushless Fuel Pumps:
1.) How do brushless Aeromotive pumps compare in size to their brush-style counterparts?
Aeromotive brushless pumps have similar dimensions and port sizes to their equivalent brush style pumps,
but may have offset inlet/outlet ports compared to the centered inlet and outlet ports on a brush pump.
Also, the mounting-hole dimensions are typically similar in width but may be closer together compared to
the longer sleeve on the companion brush-style pumps. Overall packaging dimensions are similar enough
however to avoid major rework for mounting space and line connections.
2.) Can Aeromotive brushless pumps handle ethanol and methanol fuels?
Aeromotive Brushless pumps feature outstanding cross-fuel compatibility and can handle most fuels from
pump gas to av-gas to jet fuel, diesel fuel, ethanol up to E98, and methanol fuels. They are not compatible
3.) How much HP will a Brushless Pump support on gas/diesel/ethanol/methanol fuel?
In practically all cases Aeromotive will provide conservative, gasoline FWHP (flywheel HP) estimates for
all fuel pumps we manufacture. In many cases, there may be additional HP ratings for other fuels. All of
our published ratings can be found on the product specific page for that particular pump on our website at
As a practical exercise, you may simply take the listed HP rating for gas on any fuel pump you’re
interested in from the appropriate product page and simply calculate the limit for an alternative fuel as
From gas to E85 take the appropriate gas HP rating and multiply by 0.7.
e.g. 1000 FWHP gas x 0.7 = 700 FWHP E85
From E85 to Methanol take the above E85 HP rating and multiply by 0.5.
e.g. 700 FWHP E85 = 350 FWHP Meth
From gas to Methanol directly multiply the gas HP rating by 0.35.
e.g. 1000 FWHP gas x 0.35 = 350 FWHP Meth
Gasoline to diesel ratios are pretty much the same, so figure 1:1 or no offset/penalty for diesel fuel.
If you’re a number cruncher or you just want to dig more deeply into the topic, there’s also a Tech
Bulletin on our website: TB-501 Fuel Pumps and Horsepower. This detailed Tech Bulletin will explain how
to calculate fuel requirements for the various fuels and with respect to the various naturally aspirated,
nitrous, and forced induction applications.
4.) Do you have a Stealth Brushless Fuel Pump for Mustang/Camaro/Corvette Stealth Tanks?
Currently, due to packaging/fitment challenges, Aeromotive Brushless Pumps are not yet configured for
the very tight confines of an OEM fuel tank installation like those of the Mustang, Camaro, and Corvette
stock tanks. There are Stealth (in-tank) versions of the Brushless pumps available for our aluminum
Stealth Fuel Cells, and for use in custom-built/fabricated fuel tanks, but that’s the limit of the Stealth
Brushless pump options at this time.
5.) Can I use the PWM output from my ECU to vary the speed of a Brushless Aeromotive Fuel
The short answer to this question is no, you can’t use the ECU’s PWM output to control a brushless fuel
pump’s speed. That said, all brushless Aeromotive Fuel Pumps are now available with an optional TVS
(True Variable Speed) motor controller installed from the factory. Brushless motors are the state of the
art in electric motor development, but they are quite different from the venerable brush style motors
we’re used to working with.
Unlike brush-style motors, a brushless motor is technically a 3-Phase AC motor, so a direct DC power
supply will not run the motor. Instead, a brushless motor requires the DC input power be processed
through an inverter, equipped with a processor, to create and manage the necessary 3-phase output pulses
required to get the brushless motor running and keep it running. This component, simply called the motor
controller, is included with all Aeromotive brushless pumps.
Unfortunately, providing a pulse modulate DC power supply to a brushless motor controller cannot control
the 3-phase output to the motor, will not vary the pump speed, and can only upset, and quite possibly
damage, the onboard brushless motor controller’s built-in inverter and processor.
This is where the Aeromotive TVS (True Variable Speed) controller comes into play. By providing a simple
0-5 Volt DC signal on a 3rd, yellow input wire built into the pump’s motor controller, like that from an
existing TPS sensor, a dedicated map sensor, even a mass airflow sensor, the pump speed can automatically
be regulated by engine demand.
Additional technical support is available on implementing TVS control strategies. Fuel Pump Installation
Instructions are available on our website at www.aeromotiveinc.com
under Tech Help, Installation Instructions. You may also contact the Aeromotive Tech Department directly by
calling 913-647-7300 and ask for Tech Support for more information.
6.) What other means are there to control the speed of an Aeromotive Brushless TVS enabled
Controlling the speed of a Brushless Aeromotive Fuel Pump may only be done in conjunction with an
Aeromotive Brushless Pump Controller with TVS (True Variable Speed) built-in. There are a number of
ways to manipulate the TVS control wire, creating a multi-step speed change or a smooth, variable speed
change. Some of these wiring options are explained in each fuel pump’s installation instructions, available
on our website here: Installation Instructions
If you would like to explore other options feel free to contact the Aeromotive Tech Department by phone
at 913-647-7300, ask for “Tech”, or by email at” email@example.com. Keep in mind these
discussions can get technical and are far easier to have in conversation as opposed to via email.
7.) What’s wrong with my Brushless pump, it makes strange noises when I turn it on, or it doesn’t
turn on right away, or seems to start and come up to speed slower than my brush style pump
when power is applied?
The Start-up sequence on a brushless motor is totally different than a conventional brush-style motor
and can be disconcerting to those who’ve never experienced it before. Because there’s no contact between the
rotor and the stator the brushless motor controller/computer must first run a sequence of
pulses to locate the stator position before the startup pulses can be generated in the correct sequence.
The result is a process that may include audible beeps or clicks followed by a sweeping motor start-up
that progresses the motor from a dead stop to full speed.
8.) Can I stage a Brushless pump, in other words, can I activate it with a Hobbs switch or
programmable output, where the stock in-tank pump runs continuous and the brushless pump only
runs at high engine load?
Due to the start-up sequence that occurs when a brushless motor receives power and the
somewhat delayed time required to get the pump up to full speed it is generally not
recommended to run a Brushless fuel pump as the second pump in a staged system. Better to run the brushless
pump with TVS controller as the primary and stage a brush style pump to turn on for additional
flow when needed than the other way around.
It is possible to run a Brushless TVS controlled pump continuously, along with a primary in-tank pump, but at full slow
speed and, using either the TPS sensor or, if boost control of the larger pump is desired, a MAP sensor could be used to
bring the second, larger pump up to full speed without any concern for startup time.
9.) Why do I need 6-gauge / 4-gauge wire for my 7/10 GPM Brushless pump when the wires coming
out of the pump are so much smaller, and how do I connect them together?
It can be disconcerting when you see the difference in the wire sizes recommended to feed the pump compared
to the wires coming from the pump, but as you can imagine, there’s a good reason why. Without getting too
wonky, wires are like tubing or pipes only they flow electrons instead of fuel or air, and the proper size wire size
or gauge, or tubing or pipe diameter for liquid or air flow, is calculated against the volume of flow required over
the length. So, the longer the length, the bigger the wire or tubing for a given flow volume. The wires on the pump
are a special grade, low resistance wire, and for their length are adequate in gauge, but the longer wires that go to
the pump, which are of a lesser quality as well, need to be commensurately larger to carry the current (electrons)
without a voltage (pressure) drop to the pump.
As for making the connection, there are butt-splice adapters that can be used that have the appropriate
wire gauge reduction built-in, but the best way is with a 4-terminal junction block with two paired groups
of common terminals. This would allow the large wire for power or ground to be fitted with the proper
ring terminal to connect to one side of the junction block lugs and the matching pump wire (power or ground)
fitted with a same size ring terminal but for the smaller gauge wire and attached to the other side of the matching
terminal block. This way you have a solid connection that won't drop voltage and either the harness or the pump
can be easily disconnected and/or reconnected with no problem.
10.) My Brushless Pump was working fine but now the wiring gets hot and/or the fuse/breaker is
Aeromotive’s new line of brushless electric pumps, particularly the Gear Pumps in the 5, 7, and 10 GPM
range, are moving far more fuel than any previous electric pumps commonly available to racers. This can
place serious, unexpected demands on plumbing, filtration, and wiring. The 7 and 10 GPM pumps require 6-
gauge power and ground supply wires, and a relay and breaker rated for 60-80 plus amps continuous. Filters,
especially post-filters, need to have not only the right size ports but ample surface area to handle the
flow and the typical debris found in more corrosive Ethanol and methanol fuels while retaining sufficient
Probably the most common cause for hot wires and tripped breakers/burned fuses is a combination of
under-wiring and the use of a post-filter that is either too small or loaded with debris and creating significant
back pressure, which in turn creates significant, unnecessary high pressure and corresponding, excessive
There are several Tech Bulletins on our website on filtration, pre-filters, and post-filters, including a
detailed case-history file example on post-filtration issues, and they’re worth checking out. If you’re
having this problem, simply remove the post-filter and run the pump, if the wires stay cool and or the
fuse doesn’t blow running the pump in the pits, that’s a pretty good sign you’ve found the problem.
11.) Why does the post-filter element in my fuel system with a Brushless Gear Pump look all
Because it clogged up to the point the pressure building on the outside of the element was so much higher
than the pressure on the inside of the element (the pressure produced by the pump to push through the
clogged element became much higher than the pressure in the fuel rail after the filter) that the structure
including the support wire inside the element could no longer keep the element round.
When this happens it can both lean the engine out and damage the fuel pump. It’s critical to have the
correct sized filters in a high flow fuel system to minimize restriction, and to maintain those filters as
required to keep the system flowing as freely as possible. There are several Tech Bulletins on our
website addressing post-filters, including a detailed case-history file example of what happens with
things go wrong that are well worth checking out.
12.) How much pressure does your Brushless Pump push?
The idea that a pump “puts out” pressure is a common misconception that causes a lot of confused
thinking when it comes to fuel pumps and fuel delivery. While it’s true that some pumps are pressure
limited, meaning they have an internal or external bypass that will limit the pressure they “put out” when
running against a dead-head or blocking style regulator, most pumps that can be run with fuel injection
have no effective bypass or pressure limiting valve.
While most good electric pumps may have a maximum pressure where the pump stalls, that’s usually well
above any normal operating pressure, upwards of 100-PSI plus, so they will put out whatever pressure the
bypass regulator is set to open and bypass. The pressure any pump puts out is determined by the bypass
pressure setting, you can make your inline pump run from 3-PSI to 73-PSI, whether it’s an A750 pump or
a Brushless 10-GPM pump, as long as you have the correct bypass regulator fitted with a properly sized return
line returning fuel back to the tank.