A Guide To Cummins Diesel Performance Upgrades

Posted on October 22 2021

A Guide To Cummins Diesel Performance Upgrades

A Guide To Cummins Diesel Performance Upgrades

Do you have a Cummins engine that you want to improve upon? Does it need a fix-up, or do you want to drive a little farther, faster? Thankfully, there is an entire industry dedicated to these types of improvements. In this article, you can see exactly what this industry provides.

The engines that come from factories are typically built for the best fuel economy. The manufacturers are not too terribly concerned about factors like speed or torque. It just is not what the general public thinks about. However, some diesel drivers (maybe people like you) care about them a great deal.

Through the use of aftermarket diesel parts, you can alter your truck to fit the specifications of your lifestyle. By reading a guide to Cummins diesel performance upgrades, you will see what kinds of changes are at your fingertips. You should review this list and see if any of the upgrades stand out.

3,200 RPM Governor Spring

The 5.9 12-valve originally sold in Dodge trucks was a great example of a low-speed diesel. In trucks with automatic transmissions, the torque converter stall speed was 2,000 to 2,200 rpm, which left very little room for power.

To extend the 5.9L’s operating range, you can use a 3,200 rpm governor spring. Using this spring to extend the fueling of the VE pump past 3,000 rpm, your vehicle will have more horsepower and be more drivable. If you get valve springs rated beyond 3,200 rpm, valve float (valve float is your piston-to-valve contact) becomes an issue. There are, however, no negative possibilities connected to this upgrade.

Transmission Tuning

Tuners modify factory engine calibration and timing. Using a transmission tuner, your diesel truck will see greater performance in its fueling, injection timing, and other parameters. Good tuning can make a tremendous impact. You will enjoy driving the truck more. The shift points will improve as well. Assuming you hold off on the throttle and high-performance tunes, you can extend the life of your 68 RFE.

Killer Dowel Pin Repair Kit

The ’94 to ’98 5.9L Cummins engines have so much promise. But the dowel pin installed during their original assembly hampers their potential. Over many years of vibrating and heating and cooling, the pin may drop down to the cam gear. It may even fall into the crank gear.

You can obtain the parts needed to eliminate this concern very affordably. All-inclusive repair kits for killer dowel pins are available aftermarket. You only need to install a locking tab that covers the dowel pin. Since the pin can only leave through the engine’s radiator side, the tab locks the pin forever.

Cold Air Intakes

Every truck can benefit from cold air intakes, which are a great, low-cost way to improve fuel economy. Cold air intakes give the diesel engine colder, denser air. The factory models that come with the engine are often restrictive, as they do not allow for a lot of air. Aftermarket air intakes increase the flow, and they offer better filtration as opposed to stock air filters.

Electric Replacement Lift Pump

The majority of drivability issues with the ’98.5 to ’02 24 valve Cummins relate to the injection pumps. The engines carry a rotary-type distributor-style injection pump called the VP44. As an onboard computer-integrated model, the injection pump stays cool from the fuel coming from the electric lift pump. The lift pump will slowly die, and the VP44 will follow along. The diaphragm will get damaged if the VP44 cannot maintain a minimum of five psi worth of supply pressure. Because the pumps are notorious for failing, many companies provide direct replacements.


The next item on our guide to Cummins diesel performance upgrades are intercoolers. Although they do not offer pickups much power, intercoolers do extend the life of a pickup truck. The aftermarket models are usually bigger, which allows for enhanced heat reduction capabilities. Since they are behind the front bumper, stock intercoolers on the 2013 to 2018 Ram HD trucks, which were fitted with 6.7L Cummins engines, are fairly small. But an aftermarket intercooler can lower Fourth Generation 6.7L Cummins’ EGTs while improving airflow. You will be better off with cooler, dense air flowing into your engine.

Better Fuel Filtration

Electronic common-rail injectors can handle higher pressure, more jobs, and tighter tolerances than mechanical units. Common rail injection was still new in 2003, so Cummins had some growing pains during their first go-around with the fresh technology. Microscopic impurities are usually why the 5.9L common-rail wears down.

If you want fresh common-rail 5.9L injectors, you will pay up to $450 apiece. It is no surprise, then, that Dodge owners want better fuel filtration. You can install a lower micron fuel filter in the engine’s factory filter housing. However, adding fuel filters that filter down to two microns is an efficacious method of lengthening the injector’s lives. Companies sell bolt-on kits that can keep the injectors alive for more than 200,000 miles, assuming you keep up with regular maintenance.

Exhaust Systems

Older diesels, like the 7.3 Powerstroke, LB7 Duramax, or 5.9 Cummins have far less restrictive exhausts than modern diesels like the fourth generation Cummins. You do not to worry about DOCs, DPF, or DEF systems with this option. You can reap the benefits of a true four or five-inch exhaust.


Pickup truck engines are not meant to remain the same. They are easily customizable and transform to fit the needs of their drivers. Cummins engines especially attract a great variety of performance upgrades. Drivers who want to improve their fuel economy can explore cold air intakes. Governor springs will enhance horsepower, and better fuel filtration will extend the life of rail injectors.

If you are looking to make a change to your vehicle with Cummins performance parts, come take a look at our amazing selection at Dr. Performance. Here at Dr. Performance, we want you to enjoy all the miraculous qualities that make you love your vehicle, and then find ways to improve the ride. You can always get more power or efficiency from your diesel engine; you just need to explore your options.

A Guide To Cummins Diesel Performance Upgrades

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