Twin-Turbo Duramax - Diesel Tech

  |   twin Turbo Duramax engine It's no secret that two turbos on a diesel engine are significantly better than one, but the problem is getting an extra turbocharger to fit. The six-cylinder Cummins engines have lots of space in the engine bay that makes mounting a second turbo easier, but the V-8 Power Stroke and Duramax engines don't have much extra real estate to park a second turbo on top of the engine. However, Nathan Wright of Maximized Performance has designed a kit for the Duramax that utilizes the stock turbo-even the Garrett variable-geometry turbo (VGT) on the LLY and LBZ engines-in the factory location and mounts a second turbo on the passenger side of the engine compartment. We met up with Brent Willsey and Jeremy Bird at Powerlabs Diesel in Idaho Falls, Idaho, to see how the twin-turbo kit was installed on an '07 LBZ Duramax.

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  |   twin Turbo Duramax truck On Dyno Driving a Twin-Turbo Duramax
Driving the truck on the road with the twin turbos was quite an experience because they build boost very quickly without any lag. They actually boost like the stock turbo, but with a lot more airflow on the top end. Probably the most impressive feature was that the exhaust gas temperatures stayed comparatively low for the amount of performance. With the tow tune, we could easily pull a large load without ever having to worry about overheating. For the Duramax owner who still wants to use his truck every day without sacrificing driveability, the MPI twin-turbo kit could be ideal. Before installing the turbos, this '07 LBZ Duramax had an output of 275 hp and 455 lb-ft of torque. The first run after the installation using the tow tune yielded an output of 569 hp and 1,124 lb-ft of torque. For the third run, Powerlabs Diesel hooked up a FASS lift-pump system and upgraded the ECU with the max-horsepower tune. This resulted in an output of 650 hp and 1,215 lb-ft of torque, so the overall gain was 375 hp and 760 lb-ft of torque at the rear wheels.