Tom Wilson
April 4, 2013

Boost-A-Pump Primer
So, what is this Boost-A-Pump box that Kenne Bell sells? The short answer, it's an aluminum box of electronics that augments an electric fuel pump's output, mainly by speeding it up. The colloquial description from Kenne Bell main man Jim Bell is “it's a pump supercharger.”

The more accurate assessment, also from Jim Bell, is it's a voltage amplifier and regulator. In other words, the BAP not only increases voltage to the fuel pump as necessary, it also supplies a steady voltage to the pump. So, despite the input voltage, it regulates to an exact output voltage, either what is preset or what a controller (the engine computer or Fuel Pump Driver Module) commands. This delivers consistent fuel-pump performance.

Kenne Bell references its BAP's via either vacuum in naturally aspirated applications, or more commonly, to boost in supercharged cars. In the later case, it activates at 3 pounds of boost, so fuel-pump operation is stock unless significant boost is present. That means the fuel isn't being heated uselessly 99 percent of the time.

Jim notes the stock fuel pump circuit is not regulated for voltage other than the overall charging system voltage of the car. This varies somewhat with headlights, air conditioning, stereo, electric steering assist, dying batteries, and other electrical loads, which can be troublesome when high electrical demands coincide with high fuel demand. A BAP eliminates this issue by keeping fuel pump voltage rock steady, a trick it can perform with as low as 10 volts coming from the charging system.

As you'd guess, the BAP keeps voltage steady by varying amperage (electrical volume of flow). In other words, when the fuel-pump demands more power to maintain its set voltage (and hence pump speed), the BAP supplies the necessary increased amperage. And the BAP can be used to “supercharge” the fuel pump by increasing the voltage set-point determined by the engine management computer.

Kenne Bell offers two Boost-A-Pumps—a 17-20 amp and a 21-40 amp—plus a dual BAP pairing for Mustangs with dual Fuel Pump Driver Modules, namely GT500s. All are adjustable for voltage using control inputs.\

Stock Coyote Pump at 17.5 Volts
40 13.5 500
50 14.2 463
60 15.0 435
70 15.6 409

Stock Coyote Pump at 20.8 Volts
40 16.0 609
50 17.0 583
60 17.3 549
70 18.2 518

Walbro 225
13.5 Volts 21 Volts
40 7.6 248 11.0 452
50 8.0 227 11.8 446
60 8.9 206 12.7 440
70 9.9 193 13.6 433

Aeromotive Stealth 340
13.5 Volts 21 Volts
40 12.8 348 20.5 562
50 13.4 327 21.2 547
60 14.2 304 21.9 531
70 14.9 287 22.6 515

TI Automotive 400
13.5 Volts 21 Volts
40 14.2 422 22.1 624
50 15.0 388 22.8 594
60 15.8 352 23.7 568
70 16.5 318 24.0 524

From the data, it's clear the stock Ford pump slots in with the familiar performance pumps. From a flow standpoint, there is little or no gain from replacing the stock Coyote pump with another single pump. Dual or triple pumps are another story.

We emphasize this data is no more than a snowflake atop the iceberg of Kenne Bell pump and fuel system data gained from its flow bench. If you have something special in mind with your KB blower application, speaking directly with KB tech support could save much time and expense.

It's tough not to conclude Ford has stepped up the Mustang's fuel system to the point where there's not a lot to be done to support meaningful power increases. It's much the same with the suspension, brakes, steering, and driveline, so we guess it shouldn't be too much of a surprise. Guess we'll just have to aim for making even more power!