Mad Shop Truck: Revmax’s 1,300-HP Cummins Dodge

When the team at RevMax set out to research and develop their 68RFE transmission line they purchased this well-worn 2WD 2008 Dodge Ram 2500 from New Mexico where it served as a highway maintenance crew truck. The poor truck was in pretty sad shape—described as “very rough.” There was also evidence that the truck had been jumped on a number of occasions, evidenced by a completely smashed oil pan and worn out suspension. To do their product development, the team made the truck roadworthy and went on to put mile after mile on it while refi ning their 68RFE transmission options.

Once they were satisfied with the transmission R&D, they decided that the truck deserved a complete makeover for how well it had treated them during the exhaustive development process. Initially the RevMax team planned on just giving the truck a good paint job, taking care of the interior and other simple things that the truck needed. But the project soon took on a life of its own and they realigned their goals to working toward making it one of the world’s fastest delivery trucks.

Before the go-fast plans were conceived, the truck was completely gutted down to the body and frame. It was handed over to the team at AJB Restorations in Kannapolis, NC, to whip the used and abused chassis into showroom shape and lay on a fresh coat of bright white paint. While they were working on it, the ST front end was replaced with an SRT-10 front end including grille, bumper and hood. Of course, the rest of the cab and bed received necessary attention as well and the factory rear bumper was ditched in favor of a smooth roll pan for a street truck look.

“ONE OF THE WORLD’S FASTEST DELIVERY TRUCKS”

To improve the Ram’s curb appeal, the RevMax crew lowered it two inches in the front and four in the rear to give it a good stance, then installed a set of Nitto 265/50R20 NT420S performance tires wrapped around Helo 20X9-inch HE879 wheels at all four corners for street driving. For drag strip use they opted to go with a pair of sticky and massive 390/40R17 M&H Racemaster drag radials mounted on 17-inch GW Race Wheels. In addition to lowering the rear, the RevMax team also relocated the shock mounts to install them vertically on the rear side of the axle for better chassis tuning ability. Then they installed a set of doubleadjustable JRI shocks to take full advantage of the new mounts. The factory leaf spring set was stripped of every extra leaf other than the overload spring to give the truck the ride height and compliance they wanted; a set of Caltracs were installed to keep the springs from twisting like a pretzel each time the truck launches.

To make sure the power is sent to both rear tires equally, the team installed a Yukon Grizzly Locker in the rear axle housing with 3.42 gears. To improve overall safety, the team at Customs by Biggun in Mooresville, NC, was called on to fabricate dual drive shaft hoops to keep the shaft contained in the event of a U-joint failure. Braking is handled by stock calipers and rotors with Carbotech pads front and rear to whoa the truck down at the big end of the track.

With all else settled, it was finally time to make enough power to make the truck go fast. Unfortunately, the transmission experts at RevMax had some issues with their first engine builds. To make sure the engine would meet their lofty goals, they turned to the team at Midgets Diesel Performance in Davidson, NC, to build a potent street/strip engine that could handle the rigors of racing in addition to the stress of everyday driving duties for the shop.

The Midgets team opted to destroke a 6.7L Cummins to 6.4L using a 5.9L crankshaft and a set of Carrillo rods to swing the factory 6.7L pistons through their bores in the factory 2008 6.7L block. A Hamilton 207/220 cam actuates the stock valves through Hamilton forged pushrods. The valves are kept under control with a set of Hamilton valve springs. Dynamite Diesel 275% over 50 LPM injectors replaced the stock injectors to provide plenty of fuel. High pressure fuel is delivered to the injectors thanks to a pair of stock CP3s (one from a Duramax and one from the Cummins) that are mounted on the engine and controlled by a PPE Dual Fueler kit. The dual CP3s get a solid supply of clean #2 from a Platinum FASS fuel pump and filter system mounted near the fuel filler inside the driver side rear fender well.

For the air to keep up with all that fuel, the build tem went with a set of Stainless Diesel turbos in a compound setup, using an S465 over a S480 5-Blade charger. The outlet of the compound turbos is routed to the inlet of a Mishimoto intercooler and a 60mm Tial wastegate is used with a CO2- charged AMS 2000 boost controller to prevent overboost. The cooled charge from the intercooler is directed into the cylinder head through a Glacier Diesel intake. EFI Live tuning was handled by Higher Power Performance for the engine and RevMax for the transmission. A Mishimoto radiator help the engine stay cool at the track or sitting in traffi c on the street. The RevMax team estimates that the engine is making about 1,325 hp and the truck has run a best time of 10.87 seconds at 124.95 mph in the quarter mile—plenty fast for a streetdriven parts truck!

Of course, a stout engine like that has to be backed by an equally stout transmission and RevMax has that covered. Rather than swap out for a 4-speed 48RE or something similar that might be better suited for racing, they wanted to show that their 68RFE could handle the rigors of track use and abuse. The engine is linked to the transmission through a RevMax billet SFI fl explate and Stage 5 Triple Disc Billet RevMax torque converter with a 2,100rpm stall speed. Internally the 68RFE gets the RevMax Signature Series 1000 treatment of upgrades as well as a manual lockup valve body for full control.

Taking what started out as a nearly junked out truck and building it into this street/strip terror shows that anything can be done with the proper skills and dedication. The RevMax team persevered through the ups and downs of a two-year build and came through with a very cool shop truck that may not be the fastest delivery truck in the world, but it is certainly one of the fastest in the Diesel World! DW