If you’re a Ford fan, there’s no doubt that you know the name Rudy’s Diesel. What you might not know is that he’s been pounding the ground building the same badass 6.4L Ford for almost a decade, developing a truck that just becomes more powerful and faster as time goes on. While Rudy built his Ford for drag racing in the ever-popular Pro Street class, he’s not above a little multi-use action as well, finishing in the top 10 at the 2017 Ultimate Callout Challenge. Is there a badder 4×4 Ford on the planet? We don’t think so.


There’s a very powerful 6.4L underneath the maze of turbo piping that surrounds the engine. While the Innovative Diesel-tuned Power Stroke has made 1,987 rwhp with nitrous, it’s still plenty stout on fuel alone.
A dual-stage nitrous system from Nitrous Express can add around 500 extra horsepower if need be. There are two small solenoids (one of which is used for spooling) and then two large solenoids that do the majority of the power-adding.
Twin 75mm atmospheric turbochargers are mounted up by the front bumper, where they can grab gobs of cool air. The 75s blow into an 80mm turbo mounted in the valley, which sends 80-85 psi of boost into the engine.

Aaron Rudolf (or “Rudy” as he’s widely known) got his start by developing Ford performance parts for the very 6.4L truck that you see on these pages. He bought the ’08 model brand-new with the intention of pushing the new platform further and faster than anyone else. By sheer work and determination, Rudy’s F-250 was the first 6.4-powered truck in the 9-second zone, and the first to break 1,000 hp at the wheels. Despite his success, the road to Blue Oval stardom hasn’t been an easy one. Rudy has been through a number of different transmission setups, engine combinations, and axle setups before the truck progressed to what you see here. Over the years, the chassis and body have been transformed to where there aren’t many OEM parts left. The doors, bedsides, and tilt front end are all fiberglass, parts that Rudy had custom made just for his drag truck. The chassis has also been modified, with a round-tube back-half, Funny Car-style cage, and a backbraced 9-inch Ford rear axle. The windows are also Lexan instead of glass, and all told Rudy figures he’s removed at least 1,500 pounds from his Ford in its ultra-light rebuild.

A huge air-to-water intercooler was fabricated by Rudy’s Diesel to keep the intake charge plenty cool. Vibrant V-band clamps are used to keep the massive volume of air and pressure from blowing the intercooler’s piping off.
An intake plenum was fabricated out of a single billet piece just for this application and directs chilled and boosted air directly to each cylinder.
The front suspension was highly modified for this drag racing application. Coilover shocks from QA1 were installed up front along with custom link arms and suspension limiters to prevent wheelies!
If you were thinking a lot was missing from the front of the truck, you’re right. A large Fluidyne radiator and Optima battery take up space behind the cab where the truck’s bed used to be.

Rudy’s truck has seen at least a dozen engine and turbo combinations since ’08, but the latest is by far the wildest. The factory block has been fitted with ARP head and main studs, and the factory crankshaft swings a set of custom Wagler Competition Products connecting rods that are connected to Diamond pistons. The heads have been ported and fitted with valvetrain components from Rudy’s Diesel, along with an ATI Dampener and Elite Diesel flexplate.

As much weight was taken out of the rear of the truck as possible. Rudy even went as far as to rebuild the complete rear section of the truck out of round tubing, which attaches to the original front frame.
The rear of the truck is quite intimidating with the open bedsides and mammoth 31-inch Goodyear Eagle drag slicks that are mounted on 15-inch Holeshot beadlock wheels.


There are no leaf springs anymore; a ladder bar suspension setup with QA1 double-adjustable shocks occupies the rear of the truck for optimum traction. The heavy stock axle has also been replaced with a back-braced 9-inch rear end with Wilwood brakes and a spool for weight savings.

The really wild stuff comes in with the fuel and air supply systems, as every component is capable of either double or triple its factory counterpart’s output. For starters, a FASS 260gph lift pump gulps up fuel and sends it to a twin K16 kit from Rudy’s Diesel, along with River City Diesel 150% injectors. The turbos are mounted in a triple arrangement, with a huge 80mm S400 from BorgWarner that is fed by twin 75mm S400s also sourced from BorgWarner. From there, air flows through a custom-built air-to-water intercooler, and is further chilled by a multiple-stage Nitrous Express nitrous system. Horsepower checks in at a dyno-proven 1,987 rwhp along with a staggering 3,005 lb-ft of torque, which makes it the most powerful 6.4L Ford out there.

The far end of the truck is occupied by safety equipment. An electrical kill switch was mounted to kill power if something is amiss with the Ford, while twin Simpson Racing parachutes are designed to bring the truck to a halt from 160-plus mph.
Rudy hangs on to a Momo steering wheel that’s connected to a tubular steering column when he’s flying down track, while a Racepak datalogger gives an immense amount of information about the engine and transmission’s operation.
Rudy’s Ford has an immaculate interior, especially for a race truck. A FunnyCar cage keeps the driver safe, while a custom dash and fiberglass doors with Lexan windows keep things simple and light.
Rudy’s passengers at the dragstrip are twin 15-pound Nitrous Express nitrous bottles with heaters and blowdown tubes.

While making power hasn’t been an issue for Rudy, putting it to the ground has been a different story. After trying numerous Ford-based setups, he finally went to a Competition 48RE transmission from SunCoast Diesel. The Dodge-based transmission features numerous upgrades including billet shafts, a custom torque converter, and an adapter plate to make it work with the Power Stroke engine.



While the new setup definitely has potential, Rudy has been honest that they haven’t got a good A-to-B pass just yet. With a 1.38 60-foot time, it’s clear the launch is there, and with trap speeds in the mid-140s with minimal nitrous, it’s clear it’s going to be fast. While mid-9s is nothing to sniff at, Rudy has his sights set on the 8s with this new setup, so look for this Blue Oval to be flat-out flying by the end of the 2017 season! DW

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