Building an '08 LMM Duramax
Performance Modifications In a Clean-Diesel World
Stock is good, but there's always room for improvement. When GM Powertrain set out to build a Duramax-powered GMC truck to help promote its new Duramax boat engine, it turned to Diesel Power to develop a concept. Knowing that it would need a truck that could tow and be reliable, we hooked GM Powertrain up with the folks at Gale Banks Engineering for the installation of an exhaust system, intake, high-performance intercooler, and one of Banks' new LMM Six-Gun programmers with the PDA option.
A balanced approach is what we were aiming for, as the intake and exhaust upgrades would allow for cooler EGTs and more airflow than the stock pieces. With the Six-Gun rated at 110 horsepower, and a 165 lb-ft increase over stock, plenty of air would be a great help. It should also be noted that no emissions equipment was compromised during this install, and all the parts and pieces work with the LMM's diesel particulate filter.
During our test drive, the truck was slowly increased from level one to level six on the PDA so the Allison transmission could try to "learn" the appropriate shifting pattern for the power increase. Once at level six, it was a completely different truck, spinning the tires at will and sprinting up to speed. The intercooler and exhaust also allowed the truck to make 38 psi of boost at its peak, which is the most we've ever seen on an LMM. Exhaust gas temperatures were completely under control at 1,400 degrees, and the truck didn't throw any codes or check engine lights. The Banks tune is also a "clean" tune, which means the DPF should live a long and happy life. Now this wild camouflaged truck not only has the looks, but the performance to match.
The PDA feature is an extremely useful addition to this buildup. It doubles as the truck's gauges, and can be set up to monitor boost, transmission temperatures, and more. It also has an EGT-limiting feature to save your engine from damage, and can also flash various warning lights if the computer sees information that isn't the norm. Also, it can work as a normal handheld device when the truck is not in use. While the Six-Gun is available with or without the PDA, we'd highly recommend ordering it.