Custom Ford F250 Powered by Cummins - Rolling Circus

Right Now, Adam Cornell, From the small town of Remus, Michigan, is on top of the world. In today's booming diesel industry, Adam's homebuilt Cummins-powered Ford has made more horsepower on a chassis dyno than anything we've ever seen. At the TS Performance open house in Bowling Green, Kentucky, Adam made 1,312 hp at the rear wheels, giving him the truck with the highest horsepower in the nation, and the first truck to break 1,300 hp. If that wasn't enough, Adam was towing a truck and trailer when he came through the gates. He unhitched his gooseneck and then posted the world-beating dyno graphs about an hour later.

Believe it or not, Adam's truck had humble beginnings as a two-wheel-drive 5.4L gas-powered utility truck. Adam already knew he wanted a four-wheel-drive Ford with a Cummins, so he had a long way to go. First, an old set of injectors was traded for a complete Ford dualie rolling chassis. The frame-on-wheels donated its front axle, rear axle, and most of its suspension components to Adam's gas truck, and suddenly his two-wheel-drive truck had four wheels providing traction. When he made the drivetrain swap, Adam also welded the Dana 80's differential together to make it a spool, and put on a 21/2-inch lift. Air springs were added for towing (or sled pulling) because Adam wanted his truck to be ready for anything.

To make the four-digit power numbers that he was looking for, Adam knew he needed a sturdy foundation. Since he has his own company, Central Michigan Performance Diesel, he was off to a good start. Adam first built a stud girdle for his 5.9L Cummins engine (which came from a wrecked '94 Dodge) and then put 14mm main studs into the block. Everything was balanced, and a set of 16:1 compression Mahle pistons were installed and fly-cut. Up top, a Scheid pulling cam and 24-valve tappets help move the air in, which comes courtesy of a heavily ported 12-valve head that Adam says flows more air than the later 24-valve version. Since the engine would be spinning at more than 4,000 rpm, a set of 60-pound exhaust springs, aftermarket valves, and titanium keepers were added.

With a stout bottom, middle, and top of the engine, Adam now turned to air and fuel. Last year, Adam dyno'd at 661 hp with nitrous, a number that he was very unhappy with. It turns out the original injectors were installed as the result of a mix-up. Oops. With a set of 5x.018 injectors by J&L Machine and a hopped-up P-pump flowing 650 cc of fuel, the big Ford made 1,111 hp with a single turbo. Now things were looking good. Since Adam had never been down the dragstrip before, he decided to give it a shot. The truck launched hard and went through the eighth-mile traps at 99 mph. By the end of the quarter, it was clear that something was wrong as Adam coasted through in 11.43 seconds at 107 mph. Adam's trip down the strip turned into a $3,000 run, as his Ford twisted a billet transmission input shaft and then blew up the turbo. After his first (and only) 11-second pass, Adam decided that his 7,820-pound Ford might be better suited for pulling, dyno runs, and 60-mph rolling burnouts than for drag racing.

Since his first turbocharger had gone kaboom in a big way with the nitrous, Adam decided to build a compound-turbo setup that could handle the drive-pressure spikes caused by running four stages of nitrous. Now Adam has an S362 with a 71mm wheel and a 40mm internal wastegate over an S480 with an 80mm compressor wheel. Before exhaust gases get to the turbos, however, they have to pass by a 50mm external wastegate which connects to a 2-inch diameter pipe and dumps directly into the 5-inch downpipe. With no nitrous and both wastegates shut, Adam will see about 90 psi of boost and over 700 hp from the big Ford. With the 50mm wastegate and internal 40mm wastegate wide-open, the truck only makes about 40 psi of boost, but that number jumps to 95 psi and 1,300 hp once the four stages of nitrous are turned on.