Duramax Diesel Hot Rod: Part Two: More Need for Speed

Spring wrap and wheelhop hurt performance and create a potential for drivetrain damage. Kennedy Diesel equipped our truck with a set of NHRA-qualified CalTracs traction bars designed to help keep the rubber firmly planted and improve the launch. These help prevent spring wrap and maintain the pinion angle during a hard launch.

Nitrous oxide is required to push quarter-mile performance into the 12s or better. The amount of fuel required for 600-plus horsepower exceeds the ability of 30 psi turbo-boost pressure to burn efficiently. The added oxygen provided by nitrous makes up the difference. U.S. Diesel Parts set us up with a two-stage adjustable NOx kit that can be fine-tuned to match current and future fueling requirements.

Power modules and programmers allow for an easy power gain and competition versions can double rear-wheel power.

The Banks Big Head turbo wastegate actuator helps raise boost pressure from a stock level of about 21 psi to approximately 30 by using a larger diaphragm, plus more spring pressure and an adjustable linkage. More air, more boost, and more fuel equals more power.

The original half-ton rear axle had to go. The strongest rear axle available for a GM six-lug application is the 14-bolt semi-floater with a 9.5-inch-diameter ring gear. Randy's Ring & Pinion, in Everett, Washington, was given the task of rebuilding our replacement axle to precision specs using an Eaton Positraction differential, new ring and pinion, and new bearings and seals.