Chad Simper lives in Vernal, Utah, but shows up at dyno events and sled pulls all over the western half of the United States. His '05 Chevy 2500HD looks pretty normal until the hood lifts up. That's when people see bright-blue and polished steel tubes twisting around a unique dual-turbo setup that crams loads of boost into the LLY Duramax engine. The Silverado is not a one-trick pony raised to destroy dynos...it's also a tow rig, sled puller, drag racer, and daily driver.
 The 6.6L, 403ci LLY Duramax...  The 6.6L, 403ci LLY Duramax is stuffed with air from a dual-turbo setup by Nathan Wright with an external Tial Sport exhaust wastegate. Believe it or not, one of the turbos is a stock LLY part that feeds into a custom big unit that uses a combination of parts from different companies. If you want to know what it's made of, you'll have to ask the builder yourself, because Chad won't speculate about the design. |  The engine programming is...  The engine programming is tweaked with custom EFI Live tuning built specifically for Chad's truck. Spent gasses exit through a 4-inch MBRP stainless steel exhaust system, and power is transferred into a Frankenstein build on an Allison transmission by Mike L. at Inglewood Transmission. |  The two brass valves provide...  The two brass valves provide a blow-off exit (and a backup exit) for abnormally high boost pressures that can knock loose fittings and cause other problems. |
Chad drove all the way from Utah to Southern California to be an alternate during our first Diesel Power Challenge West. His points were recorded, but since all the original competitors showed up, his scores were not tallied in the final results. That didn't deter him from going all out in every event and proving his engine setup is strong and reliable. We witnessed another display of diesel devotion and good sportsmanship when Chad showed up in Idaho towing a competitor to the '06 Dog Days of Summer. Using a 31/44-ton truck to pull a flatbed loaded with another 31/44-ton truck for hundreds of miles for a few minutes of time on a dyno? That's what we like to see!
 This Chevy 2500HD is no stranger...  This Chevy 2500HD is no stranger to the dyno wheel. At the first Diesel Power Challenge West, the 3/4-ton truck pulled 541 hp and 1,094 lb-ft of torque. A rogue deer caused a little damage to the front passenger fender, but did not stop the truck from making a best-ever dyno run of 564 hp and 1,144 lb-ft of torque during the Bully Dog '06 Dog Days of Summer in July. That's without the use of nitrous, water/methanol injection, or the dual CP3 pumps. |  Chad's truck has run a best...  Chad's truck has run a best quarter-mile time of 12.713 seconds at 106.95 mph. He managed that elapsed time using custom tuning via EFI Live. And that was at an altitude of 6,700 feet. Diesel drivers at sea level better watch out for this dual turbo Duramax sleeper. |  |