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Dr. Performance’s Cummins Race Engine

1600 LB-FT & 6,000 RPM

Jason Sands
May 1, 2011
Photographers: Jason Sands
Dr. Performance is a company that’s been at the forefront of diesel drag racing for the last decade. It currently has two tube-chassis drag trucks: one powered by a common-rail Cummins, and the other powered by the mutant 12-valve you see here.
Photo 2/2   |   1105dp 1600 Lb Ft Of Torque Cummins Race Engine engine Shot
A wide powerband is useful for drag racing, and since this truck doesn’t run a lockup converter behind its five-speed Liberty Bruno transmission, a high-rpm engine had to be utilized to keep the converter efficient. The result is an engine that can produce 1,600 lb-ft yet still spin to the stratosphere.
The engine’s foundation consists of a 12-valve block with a common-rail head for superior airflow capabilities. A Dr. Performance camshaft, cut from a billet blank, works with a set of its custom valvesprings. Airflow comes from a mammoth 80mm turbocharger that produces 70 psi of boost, and a multi-stage nitrous system. No intercooler is used. Does it work? You bet! The Dr. Performance drag truck has numerous 8-second quarter-mile passes under its belt at more that 160 mphindicating it makes about 1,200 hp. Launching at 35 psi of boost and shifting at 5,000 rpm, the truck has run a best of 8.32 seconds at 166 mph.
  • ZZ Fabrication intake with burst panel in case of nitrous backfires
  • Dr. Performance electric water pump
  • Ram-air assist to turbocharger
  • Air shutoff in case of runaway
  • Dr. Performance T-4 wastegate spacer with 60mm wastegate
  • Three stages of nitrous with multiple nozzles per stage are used instead of an intercooler
  • Custom dry-sumo oiling system
  • The NX nitrous system uses a common-rail-like manifold to feed the four huge solenoids mounted to the raidator support
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