We learned some things in 2025 that completely reshaped how we think about diesel performance, and a lot of it challenged what most people assume about power, smoke, and tuning.

This episode of the Power Driven Podcast is a year end breakdown featuring the Power Driven Diesel crew reflecting on everything they tested, broke, and learned throughout the year. The conversation covers diesel performance across multiple platforms including 12 valve Cummins, common rail Cummins, and VP44 setups, along with what real dyno testing and track time revealed. From R&D and turbo testing to race truck builds and tow rigs, this episode explains why small details in air, fuel, and timing matter more than chasing parts alone.

One of the biggest topics is smoke versus power and why adding fuel does not always mean more performance. They dig into the question of whether smoke adds power on a diesel and explain how different platforms respond, especially comparing older 12 valve technology to modern common rail engines. The discussion naturally leads into AFR tuning, running lean versus rich, and how nitrous diesel tuning completely changes the equation when it comes to heat, burn efficiency, and timing. There’s a deep look at nitrous on diesel engines, including why pulling timing with nitrous is critical, how automated nitrous control improves consistency in diesel drag racing, and why feed line size and solenoid flow actually matter.

Turbo upgrades and truck builds are another major focus. The crew breaks down real dyno results from turbo testing on different trucks, including the Junker drag truck, Windy, and Willard. They talk through GT55 and Aggressor turbo results, injector sizing lessons, and how some setups made more power than expected without bending factory rods. There’s also insight into wastegate testing, comparing screamer gate versus hot pipe gate setups on compound turbos.

The episode wraps with lessons on VP44 Cummins performance, towing capability, camshaft upgrades, cylinder head flow testing, and why there’s still a lot of untapped potential in Cummins head design.

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