 A banjo bolt (arrow) on the...  A banjo bolt (arrow) on the stock turbo feeds oil through a braided line to the second turbocharger. |  The whole installation took...  The whole installation took approximately eight hours, and the kit was very well made and easy to install; no fabrication or cutting was required. |  To increase and custom-tune...  To increase and custom-tune the fuel delivery to match the new turbos, Brent Willsey used EFI Live to download a custom map created by Rob Coddens for the truck. Two different maps were created: a mild tow tune, and a max-horsepower tune. We strapped the truck on the Powerlabs Diesel dyno to measure the gains using both of the tunes. |
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.