Everyone knows that airflow equals power, but what about fuel? All the air in the world won’t make one single horsepower if it isn’t mixed with the proper amount of fuel in the combustion chamber. To illustrate the point, consider the age-old adage that “the really fast guys don’t care about dyno numbers.” If there’s an element of truth to this, there’s a very simple reason why. In the walk of classes like Outlaw 10.5 and Pro Mod, where severely boosted and squeezed motors often eclipse the 3,000hp mark, it’s hard to find a dyno that won’t go kaput when subjected to such extreme abuse. In this elite realm of combustion nirvana, where it’s difficult to directly measure engine output, calculating horsepower is all about keeping track of fuel consumption. Measure the volume and rate at which an engine burns fuel while going down the track, then compare it to well-established BSFC standards for engines of your type, and you’ll have a very good idea of how much horsepower it’s making.
Obviously, feeding an engine the proper volume of fuel is a very big deal, and the incredible rate of horsepower proliferation in recent years has forced the aftermarket to keep pace. These days, dinky little in-tank pumps can flow as much as the big external race pumps of just a few years ago. Furthermore, massive fuel flow is no longer an eardrum-busting affair. Recent innovations have made it possible to fuel 2,000hp motors in whisper-quiet fashion. If it all sounds too good to be true, then there’s a good chance you need to get up to speed with the latest in fuel pump technology. To help you do just that, we got in touch of Jesse Powell of Aeromotive and Liz Miles of Holley, and had them explain it all to us. Chances are there’s an antiquated pump in your ride that’s begging for a replacement.
Carb Race Pumps
Jesse Powell: When it comes to serious drag racing, there are two common choices of pumps in Aeromotive’s lineup: the A2000 and our billet belt drive pump. The A2000 flows 350 gph, and is by far the most popular. This pump is a carbureted drag race–style pump, and it’s used by 80 percent of all Pro Stock racers, like Mike Edwards, Jeg Coughlin Jr., and Erica Enders. It is also the choice for most sportsman racers from Stock and Super Comp, all the way to some Pro Mods and Pro Nitrous racers. In high-horsepower EFI applications, our billet belt drive pump, PN 11105, is very popular. With the horsepower levels of extreme EFI engines, these types of mechanical pumps are becoming much more common. A mechanical pump is by far the most efficient way to provide that much fuel at EFI pressures. In fact, a good example is four-time Hot Rod Drag Week champion, Larry Larson. He runs a ’66 Chevy II with a twin-turbo EFI Moran big-block Chevy. When he races, he uses the belt drive pump. When he is running down the road for 1,300 miles during Drag Week, he fuels the motor with an A1000 fuel pump.
Liz Miles: Fuel pumps can utilize different types of pumping mechanisms, and Holley pumps rely on both gerotor and rotor/vane designs. Our HP 125, HP 150, billet inline HP, and Dominator units are gerotor pumps, while the Red, Blue, and Black pumps use rotor/vane designs. The rotor/vane pumps consist of a round housing and round rotor mounted on an eccentric. The eccentric has vanes that push out to the inside walls of the housing, and the vanes push the fuel from the inlet to the outlet. These pumps are louder, largely because the vanes clatter and pulsate the fuel heavily while a gerotor doesn’t. They do a great job of pumping a lot of fuel at lower pressures.