Cummins P-Pump Tweaks: A Triple-Digit Horsepower Gain For $0

P-Pump Tweaks

Mike McGlothlinPhotographer, Writer

Free horsepower has a nice ring to it, doesn’t it? In this day and age, it’s almost a foreign concept to think that you can add power to any vehicle without first opening up your wallet. However, there was a time when turning wrenches led to solid performance gains. For the ultimate example of low-buck power-adding, look no further than the ’94-’98 3/4- and 1-ton Dodge Rams equipped with the 5.9L Cummins. Thanks to being graced with the Bosch P7100 injection pump (aka the P-pump), 100 hp or more can be unleashed once a few key areas of the mechanical pump are modified. All that’s required is a little bit of your time and a few simple handtools.

If you’re still using one of these old Dodge workhorses around the farm or are thinking of picking one up because it’s cheap and will last forever, don’t be surprised when it struggles to keep up with traffic. These mild-mannered mid-’90s Rams only sent 135-150 hp to the pavement in stock trim, which is all the more reason to break out the wrenches and turn up the P7100. With the fueling tweaks listed here, you can darn-near double the factory horsepower rating while tripling torque output—and it won’t cost you a thing! And for those of you who don’t plan on stopping with the freebies, we’ve also included a few subsequent steps you can take in your pursuit of additional power.

*Note: all performance gains mentioned in this article assume that the truck you’re starting with is mechanically sound (i.e., a P7100 in good overall health, a strong lift pump, and injectors with adequate pop-off pressure).