BLUE OVAL DOMINATION

THIS 1,800-HP F350 IS THE WORLD’S QUICKEST FORD 4X4
A few years ago, nobody thought diesel drag trucks were going to be fast, and in some respect, that’s still the opinion. That’s why Taylor Overcash (cool name, right?) sought to build a 4×4 diesel that really would haul the mail, not just for a diesel, but for anything. Luckily, Taylor lives in the heart of eighth-mile performance in Concord, North Carolina.

Since Taylor is a Ford guy, building a Ford came naturally to him, but what he didn’t want was something heavy, or Cummins-powered. What he came up with was pure magic. Taylor wanted to take full advantage of his truck’s 4×4 capabilities, so he started out with a longbed, to ensure the front wheels did their share of the traction duties (think less weight transfer). At the time, Taylor was looking at running Pro Street, which specified that a portion of the frame be factory. Taylor kept the center frame under the cab, but that was about it, as the truck went to Customs by Bigun to have both a front-half and back-half chassis built.

The 6.4L Power Stroke engine in Taylor’s Ford has seen two years of hard use and more than 100 eighth-mile passes yet still remains stout–even while producing an estimated 1,800 hp!

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Since he would be re-fabricating the entire truck anyway, Taylor went with fabricated Ford 9-inch axles both on the front and on the rear of the truck. Due to the truck’s weight, Bigun also installed a unique wishbone four-link suspension arrangement, to ensure there were no bent panhard bars. A rack and pinion steering setup is used up front, and lightweight disc brakes are on all four corners of the truck. The chassis (and rollcage) have a 25.6 certification, which means that it’s good until 5.00 in the eighth mile.

Before he dove into his drag truck project, Taylor had the absurd experience of trying to make a 10,600-pound F450 go fast. It sort of worked (for the size of the truck) which meant Taylor already knew how to build big power for his drag truck. Taylor kept the 6.4L engine, but gave it a full rebuild. The re-vamp included a balanced crank from HED in Mooresville, NC, a set of R&R connecting rods, and lowered compression Mahle pistons. In an interesting move Taylor also went with a dry sump oiling system to keep pressures exactly where they should be, along with standard menu ARP head studs to keep the head gaskets in check.

We asked about jet sizes, but since Taylor uses 5 stages and a progressive controller, it’s fairly complex. What we can tell you is that he uses nearly 5 pounds of nitrous per eighth-mile run, or about a pound a second!

“Real” race engines almost always use a dry sump oiling system, so Taylor did too. Advantages include a greater capacity, better cooling, more consistent pressure, and ground clearance.

When it came to making power, Taylor chose the simplicity of a medium-sized turbo and a LOT of nitrous. Taylor figures that the engine makes about 900 hp to the wheels on the T6 S475 turbo alone, and then a whopping 5 stages of nitrous adds another 900 hp bringing the total to a wild 1,800rwhp. The fuel system is just as interesting as the rest of the engine, and triple (yes triple) K16 pumps are supported by a FASS 260 gph lift pump, and are tuned through an H&S Mini Maxx.

Even with big power and a light chassis, there are still a lot of odds and ends that get a truck down the track. One of the major ones is the transmission, and again Taylor stuck with the Blue Oval and went with a 4R100 automatic built by Twisted Diesel and controlled with a PCS controller. Insanely hard launches are achieved with a 2,100-rpm stall DPC Converter, and the truck gets stuck to the track via JRi shocks and Mickey Thompson tires.

Another race engine trick is individual exhaust gas temperature (EGT) monitoring, that way Taylor can see if anything is amiss in a certain cylinder. He monitors this and a multitude of other parameters through a Racepak data logger.

Wastegates are extremely important in keeping boost regulated, especially with nitrous. Taylor uses twin Turbosmart wastegates to keep from overboosting the 6.4L engine.

Drag racing all starts with the launch, and Taylor’s best 60-foot of 1.19 seconds is one of the Nation’s best for a 4×4 diesel. From there pound after pound of nitrous is added until the truck blazes through the traps at low 5s at nearly 140 mph. Taylor’s best of 5.12 at 138 mph makes him one of the top 5 4x4s in the country, and at 4,200 pounds no less. We also applaud Taylor for sticking to his guns and sticking to the blue oval and showing that yes, diesels can fly!