It's a well-known fact that unlike their gasoline counterparts, diesel engines throttle on fuel instead of air. So it comes as no surprise that when you're upgrading the output of an oil burner, the first step is to find ways to feed it more fuel.

Increasing injector size and pulse width are typical methods, but that comes with a caution: when you increase the volume of fuel sprayed into the cylinder, the pressure drops in the line between the pump and the injector. That in turn reduces atomization, and those bigger carbon-based molecules burn less efficiently, pushing fuel out the exhaust manifold, producing the clouds of black smoke commonly seen at diesel drags. Not only is that wasted energy, it also spikes the exhaust-gas temperature, causing a host of other problems.

One of the first steps, then, in the performance upgrade of a common-rail diesel ('03 and later Cummins and Duramax), should be increasing the fuel flow from the pump. The CP3 pump is a good unit, but since it has a positive displacement configuration, it can only move a fixed volume, hence the need for some backup. ATS has a relatively simple way to add a secondary CP3 pump. The system also includes a computer to coordinate the increased flow, since two pumps are doing the work of one.

Clint Cannon of ATS points out that the immediate result of this install, even on a stock engine, is a crisper tip-in of the throttle response, along with an improvement in miles per gallon. He also says he seen the EGT drop as much as 200°. But he emphasizes that these benefits all depend on precise engine tuning, and the ATS system includes a custom fuel curve in the computer module.

The improved mpg of a dual-pump setup might sound counter-intuitive, but note its purpose is not merely to increase volume, but also to maintain optimum pressure, and thus improve the fuel burn, which is what a performance diesel is ultimately all about.

Source:

ATS DIESEL PERFORMANCE
(800) 949-6002
www.atsdiesel.com