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Diesel Performance Basics

More HOrsepower & Torque for your Cummins, PowerStroke, or Duramax




For a comprehensive guide to diesel performance, please visit Diesel Hub's Diesel Performance section.


OEMs are conservative when they design your engine, and have to take into consideration a magnitude of variables before the finalize an engine's horsepower and torque ratings. One of the great things about electronically controlled diesels is the unmatched performance potential that can be unlocked with relative ease and at an affordable price. And with the higher overall strength of a diesels robust components, your Cummins, Power Stroke, or Duramax can handle a considerable bump in performance with minimal concerns. For our "Performance Basics" article, we've outlined some simple modifications that will help you make more horsepower, torque, and even use less fuel. As with any modification, consider the side effects before you get to hot and heavy into picking parts. Head studs and a pyrometer and highly recommended before installing any component that significantly alters fueling characteristics.

Performance Engine Tuning

Engine tuning comes in many forms - chips, programmers, tuners, but the basic function of all these parts is similar. These products modify engine parameters in favor of increased performance. Often times this includes, but is not limited to, higher fuel injection pressures, longer injection events, and altered timing. Engine tuning is easily the best bang-for-the-buck method of increasing performance, with some products increasing torque by more than 300 lb-ft. And when your foot is not buried in the throttle, you'll experience improved fuel economy on most models. Search for a model from a reputable manufacturer who can produce proof to warrant their claims. Be weary of "50 mpg" advertisements and other outlandish claims.

Air/Intake Mods

Aftermarket filter kits and intake horns are also an affordable way to increase performance. Additionally, reducing intake tract restriction will enhance throttle response and reduce turbo lag. Upgraded intercoolers are good for a few additional ponies as well. These modifications will also help keep EGTs at manageable levels. Cold air intake kits and air horns can be acquired at reasonable costs, though the horsepower per dollar ratio is lower than with engine tuning.

Performance Exhaust System

No performance build is complete without a performance exhaust system. Reducing restriction in the exhaust will improve turbo response and provide torque increases throughout the entire powerband. A complete performance exhaust should include a free-flowing downpipe, muffler/muffer delete, as well as an attractive tip to add some flare. Many companies also offer DPF/DOC delete kits, which are only allowed on off-highway vehicles. While they are illegal, deleting the DPF can yield huge fuel mileage improvements as well as increased performance.