The Dr. Performance Nitro Series Dodge Dakota drag truck set new Diesel Hot Rod Association (DHRA) Pro Diesel class records at the 2007 ATS Diesels on the Mountain event: 8.48 seconds at 164.23 MPH. This elapsed time and top speed, set at Denver's Bandimere Speedway, are both records. DHRA rules require a "back-up" run within 10 percent for a record to be official: Charlie Stewart solidified the 8.48 pass with an 8.312-second pass.
"Unfortunately, we stuck a piston on the faster pass and weren't able to back up that time," Stewart says. "We have about 100 passes on the engine, and we're amazed that it's lasted this long without a rebuild." Team owner Kenny Laughlin adds, "Our goal for this season is to get an official time in the sevens, and we're right there if you take into account Bandimere's elevation [5,800 feet above sea level]."
Previously known as the "Predator," Dr. Performance's renamed "Nitro Series" 5.9L Cummins-powered Dodge Dakota has run a best "fluke" time (yet to be backed up by another time within 10 percent in the same year) of 7.82 seconds at the 2007 DHRA Indiana Diesel Nationals.
The Nitro truck's chassis was built by Jerry Bickel Race Cars. Now in its third season with this truck, the Dr. Performance team consistently posts faster times than the diesel-powered dragsters. (Dr. Performance will unveil its own diesel dragster and a second, shorter-wheelbase Pro Street diesel truck at the 2007 SEMA Show.) Amazingly, the Nitro Series hasn't experienced any driveline problems.
Power begins with a 12-valve Cummins 5.9L engine. "They're readily available and are a little lighter than the 24-valve blocks," driver Charlie Stewart says. The engine was built in-house with a combination of production and prototype parts. "Tricks" include friction and ceramics coatings on internal and exhaust components by Polydyne (Houston, Texas). Also, Dr. Performance modified the P-pump and ported the heads for superior flow. Proprietary fuel injectors developed with Industrial Injection and a custom camshaft grind to a Bullet billet blank should be available to the public soon. Dr. Performance also plans to offer high-performance Cummins crate motors in the future.
Regarding ongoing quarter-mile records, Dr. Performance driver Charlie Stewart says, "This sport is fairly new, and there are still a lot of things we haven't tried yet. We've only been running 40 pounds of boost. Since Houston is the last event of the year, we'll crank it up on each run to see what happens when we run 60, 80 and maybe even 100 pounds of boost. We think we can get in the 7.60s."