Banks Power L5P Duramax Tuned To 912 HP and 1,389 Pound-Feet of Torque

445 horsepower and 910 pound-feet are the crank ratings, namely 451 PS and 1,234 Nm in the metric system. As with any other turbo diesel for heavy-duty trucks, the L5P Duramax delivers maximum torque at merely 1,600 rpm.

Engine guru Gale Banks, however, can do better than General Motors at the expense of reliability. In a series of videos on YouTube, the Banks Power team aims to “scientifically kill” the 6.6-liter blunderbuss with a plethora of modifications that you’re not likely to see out on the street.

Strapped onto the dyno, this L5P delivers no fewer than 912 horsepower (925 PS) and 1,389 pound-feet (1,883 Nm) of torque. For reference, that translates to more ponies than the Lamborghini Aventador SVJ and almost double the torques of the Dodge Challenger SRT Hellcat with the Redeye upgrade.

The most impressive thing about Banks Power’s modding spree is that the Duramax still runs the stock internals. Among those modifications, Gale and his crew have fitted 2.25” up-pipes feeding a 3.0” forged collector. The factory mounting foot for the turbo had to be scrapped, the intake was upgraded as well, and the exhaust gases exit the system through a conical diffuser and a 5.0” pipe.

That level of horsepower and torque also means that Banks had to protect the crankshaft with a Fluidampr viscous vibration damper. Even more importantly, the way Gale talks about the tuned L5P over the course of 25 minutes beggars belief. You can certainly tell that this guy is genuinely passionate.

Back in the real world, the main competitors for the Duramax in the heavy-duty truck segment are the Power Stroke V8 from Ford and Cummins straight-six turbo diesel from Ram. The Blue Oval's engine develops 475 horsepower and 1,050 pound-feet (482 PS and 1,424 Nm) while the Ram 3500 HD is available with a high-output version of the Cummins with 400 horsepower and 1,000 pound-feet (395 PS and 1,356 Nm).