Performance upgrades for 5.9L 24V Cummins engines can improve horsepower, torque, throttle response, towing ability, and overall engine performance. The 24-valve 5.9L used in 1998.5–2002 Dodge Ram trucks is equipped with the electronically controlled Bosch VP44 injection pump, making its upgrade path different from both the earlier 12-valve and later common-rail Cummins engines.

Lift Pump Upgrade

A reliable lift pump should be one of the first upgrades on a VP44-equipped truck. The VP44 depends on adequate fuel supply, and an upgraded lift pump can provide more consistent fuel delivery while helping protect the injection pump. Current 24V performance guides commonly recommend a higher-capacity lift pump and fuel-pressure monitoring as foundational upgrades.

Performance Injectors

Larger injectors can provide additional fueling for a modified engine. However, injector size should be matched to the turbocharger and VP44 setup. Adding more fuel without enough airflow can increase exhaust gas temperature and reduce efficiency.

Turbocharger Upgrade

A properly sized turbocharger is one of the most effective performance upgrades for 5.9L 24V Cummins trucks. The factory turbo can become a limitation as fueling is increased.

S300 turbochargers are available as direct-bolt-on upgrades for 1998.5–2002 24V Cummins trucks, with different compressor sizes intended for different power targets.

A towing-focused build generally benefits from a responsive turbo, while a high-power build may require substantially more airflow or a compound-turbo arrangement.

Intake and Exhaust

Improving airflow can complement turbo and fueling upgrades. High-flow intake components, upgraded intake horns, intercooler piping, and a less restrictive exhaust system are common supporting modifications.

A 4-inch exhaust is frequently used on modified 24V trucks because it provides additional exhaust-flow capacity as fueling and turbo airflow increase.