12-Second Daily Driven 2009 Duramax
This Fire-Breathing LMM Makes 700 HP With A Stock Long-Block
In late 2009, GM announced it would be shutting down its DMAX engine plant for 18 weeks in order to make its engines meet emissions standards that would take effect on January 1. Shortly after, '08 to '10 Chevy and GMCs powered by the outgoing LMM engine became hard to find on dealer lots. About that time, Dallas Penn of Sun Coast Converters was on the hunt for a 2500HD. "It didn't take long to find it," he told us. "My '09 was the only new Crew Cab, short-box Duramax in all of Denver."
Dallas always knew the Duramax had great potential for making high horsepower after modifying his father's '02 LB7, so he jumped right in-and did all the work himself. Within the first 500 miles, the diesel particulate filter was removed and EFILive tuning helped add some power to the mix. Next, Dallas outfitted the Allison 1000 with a TransGo Jr. Shift Kit in his driveway, installed an AirDog II 165-gph fuel system, and added aftermarket tie-rod sleeves and a billet centerlink from Empire Diesel Performance.
In June of this year, Dallas' family became part owners of Sun Coast Converters in Fort Walton Beach, Florida. "I knew I had to step up my game, since the whole industry would be looking to see what the new Sun Coast would bring to the table," he said. So, Fleece Performance Engineering got the call and helped work out a solid, reliable, 700hp recipe for the truck. The catch? It would be done with a single turbo, on fuel only, and rely on the stock LMM long-block.
A twin CP3 injection pump kit from ATS was added to share the job of creating fuel pressure, and the stock injectors were pulled and outfitted with 65-percent-larger nozzles from Fleece Performance. Exhaust modifications included ridding the LMM of the factory EGR system by way of Screamin Diesel Performance's EGR delete kit, adding PulseFlow exhaust manifolds and up-pipes from ATS, and bolting on a 3-inch downpipe to 4-inch piping to a 7-inch mitre-cut stack.
Although the factory variable-geometry Garrett was ditched, the truck retained its quick spool-up manners thanks to an S300-based turbo from Fleece Performance. Its fixed-geometry 66mm Cheetah unit features a 66mm compressor wheel and a 73mm turbine wheel. Tuning the truck was left to Brayden Fleece. A DSP5 switch was mounted on the driver-side A-pillar and allows Dallas to change tunes on the fly. To handle the extra boost and avoid any head gasket issues, Dallas threaded a set of ARP head studs into the block.
As if you had to guess, all the newfound power makes its way through a Sun Coast-built transmission. A complete buildup of the six-speed Allison included key components like billet input and output shafts, Sun Coast's new GMax rebuild kit, and its bulletproof 1057 triple-disc torque converter. Thanks to the solid transmission, the truck has been able to put 678 hp to the wheels on a chassis dyno and run mid-12-second quarter-mile times at the dragstrip.
Dallas is definitely making a name for himself, and his truck is an ideal representation of the diesel industry-not to mention the Sun Coast name. This may very well be the new face of Sun Coast Converters-a staff loaded up with 600, 700, even 800hp daily drivers that you can see for yourself at national diesel events. Within just half a year's time and 19,000 miles, Dallas transformed a bone-stock LMM into a 12-second, fire-breathing daily driver. If that doesn't explain the power of the diesel addiction, we don't know what does.