The fuel is delivered under extremely high pressure to allow for faster, finer spray of fuel into the combustion chamber. The shape of the fuel bowl in the piston tops is also carefully designed. Oxygen is added to enhance combustion by a turbocharger to deliver more air as fuel is delivered. With more oxygen available, the fuel burns more completely, and the modern diesel engine runs exponentially cleaner than pre-2008 engines. What's left, mostly a form of soot, is captured in a ceramic filter located downstream and periodically burned off. A standard Duramax is rated at 365 horsepower and 660 pound-feet of torque.
The Banks engine differs from that formula in that it uses two turbos that spool up together and adds still more oxygen in the form of nitrous oxide, so every last atom of diesel fuel can be converted into power.
And it's clean. "We do it by not overfueling," tuner Matt Trainham explains. "We add O2 in proportion with fuel using two turbos and nitrous. It keeps EGTs down, keeps mileage up, and makes really good power. Our air/fuel ratio, 28:1, is leaner than that of most stock trucks."
The truck used a brand-new engine for its record-setting run. The heads contain big valves and are custom ported for airflow. "Lots of cam and a huge exhaust" are part of the formula to allow the engine to turn 5800 rpm, incredibly high for a diesel. Stout rods and newly designed pistons are made to spec by outside vendors, and a new material was used in the crank bearings. The new Banks Duramax can generate more than 1300 horsepower, but nobody is exactly sure how much, because it exceeds the ability of the shop dyno to measure the output.