Turning A Used-Up Cab And Chassis Into A 700-HP Monster

The Underdog: From Used Cab & Chassis to 700-HP Monster

Normally, when you see a diesel screaming down the drag strip in the 11-second range, it’s not a 6.0L Ford. Truth be told, though, the much-maligned platform does have some performance potential. Starting with a well-used 6.0L Ford, John Roberson and Harlan Clemons—owners of Outlaw Diesel Performance in Greenfield, Indiana—set out to prove it.

The team of John, Harlan, and head mechanic Matt Campbell started their trick street truck build by acquiring a cab and chassis Ford. This truck was white with a large service bed. If you’re thinking that this is miles away from what’s seen on these pages, you’d be right. Since they had to cut the frame, the team decided that a short bed seemed like a good idea. This would save weight and look good too. A 20.5-inch section was cut out of the frame behind the cab, along with another 8 inches on the rear of the truck, where it was extended.

The team did it right, by Z-cutting the frame, then boxing in the section that had been re-welded. A short bed was then sourced and added, along with a Street Scene roll pan for the rear of the truck. A 2008 tailgate was also added, along with Harley headlights. Then the final touch came in the shop, where the whole truck was sprayed gunmetal gray, because, hey, that’s a lot more exciting than plain old white.

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Since the Ford’s whole purpose was to be fast, the engine also received a number of upgrades. A rather large 68mm VGT turbo with a BatMoWheel was sourced from River City Diesel. It was installed on the truck along with, comparably large, 245/100 injectors from Warren Diesel. A high-pressure oil pump off a 2003 model maintains injection pressure, while a Walbro 392 electric lift pump supports the whole system. Thanks to its relatively light 6,490-lb race weight, the truck runs in the 12s with ease. However, a dip into the 11s required slightly more oomph. This extra power came in the form of a Nitrous Express nitrous oxide kit, which adds about another 150-200 hp to the combination when triggered.

With that much power on tap, the rest of the driveline and chassis also had to be upgraded. The stock 5R110 transmission was replaced with a top-of-the-line unit from River City Diesel. This transmission features heavy-duty clutches, billet input, output and intermediate shafts, and an improved low-reverse hub, as well as upgraded planetaries. The factory torque converter was also replaced with a triple-disc converter from Precision. It features a rather loose 2,300-rpm stall to allow the big turbo to spool up quicker. In addition to the transmission modifications, the deep-geared rearend was fitted with a Detroit Locker, and homemade traction bars built by Outlaw Diesel.

When we ran into the team at Rudy’s Diesel Fall Truck Jam, they were having traction issues caused by deep 4.10 gears and a lot of nitrous out of the hole. With a spinning 1.79-second 60-foot time, they were still running low 7s in the eighth-mile. The truck has run a best of 11.68 at 118 mph in the quarter-mile. Since it’s now mostly a toy, John and Harlan are fitting the truck with M&H cheater slicks on all four corners, and aiming for 10.50s for the upcoming year of racing. We’re glad to see a 6.0L mixing it up with other quick trucks, and with what they’ve done so far, we have no reason to doubt they’ll go even faster next year. DW

The engine in Outlaw Diesel's short bed conversion has an estimated output of 700 hp to the wheels. — The engine in Outlaw Diesel’s short bed conversion has an estimated output of 700 hp to the wheels. This is thanks to a number of upgrades and a healthy shot of nitrous.

A rather large 68mm VGT turbocharger from River City Diesel is used to propel the truck to 12-second elapsed times on fuel alone. The turbo has been outfitted with a Bullseye Performance BatMoWheel, and sends 36 psi (42 psi on nitrous) to a ported Stage 2 Oliver intake.

With a larger turbo than factory, a lot more airflow is needed for the engine to make more power. An S&B intake solves the airflow problem, and draws in cool outside air to boot. Look closely and you can see the intake snout, forward of the core support.

A single nitrous express solenoid is a big power-adder for the Ford. With only a medium amount of boost pressure, the nitrous adds a bunch of extra oxygen to the mix. The result is about 150-200 rwhp with a single .093 jet in the system.

Even on a truck that's used mostly for drag racing, reliability basics need to be addressed. — Even on a truck that’s used mostly for drag racing, reliability basics need to be addressed. Goodies like ARP head studs, River City Diesel valve springs and pushrods, a Sinister Diesel coolant bypass (seen here), and a race only EGR delete were installed to make sure the truck makes pass after pass.

To increase airflow and add some cosmetic style, a No Limit Fabrication cold-side intake pipe was installed. Since we shot the photos seen here, a hot-side pipe was installed as well.

Irate Diesel makes fuel pump system using twin fuel filters and a Walbro 392 lift pump. Custom fuel lines from Outlaw Diesel were run from the pump up to the engine and back to the tank.

Nitrous Oxide works best at a constant pressure. A large 15-lb bottle and heater from Nitrous Express keep bottle pressure at a serious 1,100 psi for optimal performance.

After the frame was cut, much of the stock hardware was removed (like the fuel tank and exhaust) and the bed is fitted with a 15-gallon fuel cell, and a 5- to 7-inch miter-cut stack from Pypes.

The River City Diesel transmission is what keeps the Ford going down the track, or down the street on short local jaunts. Built with parts like upgraded shafts and a triple-disc torque converter, the transmission is stout enough to handle the torque of the nitrous-fed 6.0L engine.

The front axle of the Ford is a strong Dana 60, while the rear end, seen here, is a nearly unbreakable Dana 80. The front differential is stock, while the rear has been upgraded with a Detroit Locker. Both front and rear axles feature 4.10 gears.

20x12-inch Moto Metal 962 wheels were installed on the truck — The truck needed to be fast, but it also needed to look the part, so 20×12-inch Moto Metal 962 wheels were installed on the truck, along with grippy 305/50R20 Nitto 420S tires.

The traction bars were built in-house at Outlaw Diesel, and are a key component in getting the short-wheelbase truck to launch hard off the line without hopping.

Multiple gauges in one unit are available thanks to a SCT Livewire monitor/programmer combo. The truck is programmed through the SCT as well, with custom tunes from Gearhead Automotive and Performance.

By looking at the rear of the truck, you'd never know it was a cab and chassis that had to have 8 inches cut off the rear of the truck. — By looking at the rear of the truck, you’d never know it was a cab and chassis that had to have 8 inches cut off the rear of the truck. Since it wouldn’t be towing, a Street Scene rear roll pan was installed to shave some weight.

At the track, the Ford has run as quickly as 11.68, although its 118-mph trap speed hints that it’ll be faster once the details are sorted out.

Drag racing is very exciting and is integral to the diesel community. Owners get to turn their trucks into total rocket ships and compete for various prizes. If you like racing diesels, check out these five GM drag-racers!

The Underdog: From Used Cab & Chassis to 700-HP Monster

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