A Texas trailblazer converts Larry Larson’s No Prep Kings ‘Caddy into the world’s first diesel Pro 275 car.
When we first met Jared Ring, he was campaigning a 3/4-ton, factory-frame, 4×4 second-gen Cummins in the NHRDA’s Super Street class. But that was years ago. Since then, he’s been busy. Very busy. After grabbing the attention of serious drag racers everywhere behind the wheel of Frosty 2.0—the low-4-second ’15 Ram that recently won the Snowbird Outlaw Nationals’ N/T Truck class—Jared and the Ring Racing team have decided to go even faster. The new goal? Unveil the world’s first diesel-powered Pro 275 car and be competitive with it. We’ve never seen anything like this in diesel—and neither has the world of radial tire drag racing. Buckle up. This car is going to stir the pot.
It puts a diesel twist on what was perhaps one of the most celebrated “stock-appearing” race car builds of all time, Larry Larson’s former No Prep Kings ATS-V. Immediately after the PRI Show concluded back in December, Jared stuffed a lightweight, Freedom Racing Engines 6.8L Cummins into the factory body, 2016 Cadillac Coupe. That was followed by a stopover at S&S Diesel Motorsport for a stand-alone MoTeC ECU and complete wiring overhaul. Then came a visit with Tin Soldier Racecars for a few chassis tweaks before heading south to Georgia for Lights Out 15. In case you’re doing the math in your head, yes, the car went from start-to-finish in just two months’ time.With a 4130 chromoly, Pro Mod-style tube-chassis, you wouldn’t necessarily expect a race car to still be sporting its factory body panels—yet that’s exactly the case. The hood, fenders, nose, doors, you name it, are all OEM, as are the headlights and taillights. The car even has a rear-view camera (we’re not kidding). The body has been wrapped in vinyl, but in the same shade of WRX blue that Larson initially had Goachers Street Legends apply. As for weight, Jared tells us the coupe checks in at 2,900 pounds currently—50 pounds more than the class minimum for a diesel running in Pro 275.No racing program gets off the ground without the right engine. After the success he’d seen with the common-rail Cummins in his N/T truck program, Jared knew the Cadillac’s power plant would also come from Freedom Racing Engines—the engine building arm of Fleece Performance Engineering. A Fleece billet-aluminum block utilizes billet, cross-bolted mains (and massive, 5/8-inch thread, H11 main and head studs from Point One) to secure a Winberg 6.7L (4.88-inch stroke) crankshaft, features ductile-iron sleeves, a 4.25-inch bore (bringing displacement to 415 ci), D&J X-beam rods, and proprietary, forged-aluminum Diamond pistons with Total Seal rings. The aluminum crankcase also houses a Hamilton custom roller camshaft, while a billet-aluminum head from Wagler tops things off. To give you an idea how much weight savings all of this aluminum provides, even with ductile-iron sleeves, main caps, and main studs included the block itself tipped the scales at a trim, 240 pounds. Fully dressed, and with Fleece’s center-feed billet intake manifold bolted in place, the engine weighed just 748 pounds.“The folks at Freedom Racing Engines are really wanting us to push this engine to the limit,” Jared tells us. We can’t think of a better way to do that than in this car. After all, given the Cadillac’s weight and the team’s goals for it, 4,000 hp will likely need to be on the table—and available at very high engine speed. With the car’s shift points already set at 6,800 rpm, a soft limiter programmed for 7,000 rpm, and a hard limiter at 7,500 rpm, we’re pretty sure Freedom has high-rpm horsepower covered, and here’s why. “Most of the combustion advancements that have helped improve our drag race program were established from years of development in the engine dyno room with our pulling engine program,” Freedom’s Chase Fleece explains. “We’ve made a major push to focus on making these engines rev. With the current combustion recipe (piston/injector), we’re able to inject fuel at such a quick rate that it’s allowed me to focus on other aspects of the engine like camshaft timing events. Because the injection event is so fast and combustion is so efficient, we’ve found a significant increase in power at high rpm.”Take one look at modern diesel drag racing and you’ll quickly realize that high-pressure common-rail is the most dominant form of injection. To get the best of the best to fuel his billet-aluminum beast, Jared partnered with S&S Diesel Motorsport. The company responded by building him a set of Ordnance 6.7 Cummins injectors and supplying a pair of its high-speed, 14mm CP3 high-pressure fuel pumps, which guarantee more than 30,000-psi worth of rail pressure is always on tap. The pumps mount via a dual, gear driven CP3 cover from Bean Machine. A Waterman Racing pump, driven off the back of the Peterson dry sump oil pump, supplies the CP3’s with diesel from the fuel cell.Another critical component to common-rail’s success exists in its electronic control. This ability to fine-tune the injection system not only plays a huge role in making raw horsepower, but also in maintaining traction. At the apex of electronic control, there are stand-alone ECU’s such as the MoTeC M142 employed in Jared’s Cadillac, which goes well beyond the factory computer’s capabilities. Installed and wired up by S&S Diesel Motorsport, the MoTeC system benefits from the company’s diesel-specific software package, for which it provides calibration and on-track support for. Race day calibration changes are typically a collaborative effort between S&S’s Andre Dusek (who spends hours at every event scouring data logs with a fine-tooth comb in order to get the most out of each pass), crew chief Daniel Pierce of Power Source Diesel, and with input from Fleece Performance Engineering’s Chase Fleece.Front, centered, and low, you’ll find the Harts turbo that force feeds triple-digit boost into the 6.8L Cummins. It’s yet another case of extreme tractor pulling technology transferring over to drag racing, with the Harts unit being cast, machined, assembled, tested, and verified in-house at its Fayette, Missouri headquarters located in the middle of sled-pull country. The single charger utilizes a 102mm (inducer) compressor wheel, a 113mm turbine wheel, and a billet, ball-bearing center section. Data from the car’s first few passes (nitrous included) revealed that the turbo builds 120-psi of boost and an incredibly low 75-psi of drive pressure.Welcome to solenoid alley. Nitrous is a big reason why modern diesels burn so clean at the track, and Jared’s Cadillac enjoys a steady diet of it thanks to Nitrous Express. All told, the car sports six active NX kits, “with a spare for later.” Three Pro Power Lightning solenoids are used to spool the Harts turbo during staging, while Lightning 375 solenoids, chosen for their efficiency and ease of tuning, are tasked with more serious N2O delivery down track. Water injection is on tap, too, and is sprayed pre-turbo in an effort to keep the compressor cool.One glimpse at the exhaust side of the engine and you know Jared hired one of the best in the business. The work went to Cody Fisher of 1X Precision, a master of his craft who’s known for fabricating headers that function as well as they look. Trust us, this isn’t just a show piece. All exhaust plumbing is made from 321 stainless steel to stand up to the kind of heat it’s exposed to. The header was also carefully crafted to achieve sufficient wastegate flow—not to mention the fact that it serves as a way to obtain true in-cylinder temperature readings.You won’t find any reference hoses, springs, or diaphragms associated with the wastegates on Jared’s engine. Drive pressure is controlled by way of an electronic StraightGate wastegate from Turbosmart. A servo motor and zero-backdrive gearbox drop current demand and offer great stability against high drive pressures. Its precise, efficient operation is tied in with turbo shaft speed as opposed to boost reference. A second StraightGate is present on the intake side, which Jared tells us will soon be used to increase shaft speed on the starting line.It’s the go-to transmission in both gas and diesel for a reason: it works. The Rossler Transmissions TH400 in Jared’s Cadillac shares quite a bit in common with its gas-intended brethren, the only real difference in this application boils down to rpm and torque converter. As for the latter component, a 12-inch, bolt-together lockup unit from Neal Chance Racing Converters is employed and features a wildly high (for a diesel) stall speed. Once through the three-speed, power is routed to the rear-end via a carbon fiber driveshaft built by Precision Shaft Technologies.Before the P275/60R15 Mickey Thompson radials apply it to the track, horsepower makes its way here, to a proven Strange Engineering modular rear end complete with a billet-aluminum Carmack Engineering third member, chromoly spool, and 40-spline axles. To keep the diesel properly loaded and within its target rpm, a Scheid 2.73 gear is part of the program. Stopping power comes in the form of Strange carbon disc brakes. Four-way adjustable, Menscer Motorsports coilovers can also be found back here. Believe it or not, the high-tech Menscer units are predominantly controlled by air, which can be adjusted as the car heads down track.After a stopover at Tin Soldier Racecars, where the four-link was dialed in and the chassis squared up, Jared and the Ring Racing team made the 700-mile trip to South Georgia Motorsports Park for Lights Out 15. There, the first-ever Pro 275 diesel entry made a few test hits and then proceeded to string some solid passes together. A 4.37-second eighth-mile was followed by a 4.17 (which was good enough for a mid-pack qualifier), and then the ‘Caddy crept even closer to 3’s on its last qualifying pass with a 4.09 at 181 mph. While bottom 1-second 60-foots are an objective (and indeed, likely a requirement to run with the rest of the Pro 275 field), a best, 1.06-second 60-foot showed promise. And despite suffering valvetrain damage which effectively put Jared and team out of contention after their E1 win, the car’s first race was a resounding success.Although 4.0’s is a far-cry from 3.7’s (one of the goals with the car), tremendous progress was made in Georgia. “The difference in a 4.09 and a 3.70—where we eventually want to be—is huge,” Jared told us. “Everything has to click on these cars to really go fast. It’s a mountain to climb, but I think we have the right setup to make it happen.” With low, 2.60 short-track times and the engine loaded harder on the big end, 3.70s aren’t out of the question, something a gear change could definitely help facilitate. Luckily, this is only the beginning for a race program that has its sights set on being the quickest diesel-powered door slammer in the world.
“Do we want to win? Of course. We’d love to grab everybody around the neck and drag them around the track. I don’t know if we have the power to do it yet, but I think within the next year we will.”
—Jared Ring
It takes a small army, and this is far from everyone involved, but this dedicated group spent a lot of late nights readying the car for its debut at Lights Out 15. Six days before the launch, S&S Diesel Motorsport invited us to its Seymour, Indiana headquarters to get a sneak peek at one of the wildest diesel race cars ever built. From left to right: Ring Racing’s Tristan Ring, S&S Diesel Motorsport’s Ryan Reiser and Andre Dusek, Power Source Diesel’s Daniel Pierce, S&S’s Luke Langellier and Carter Langellier, driver Jared Ring, and S&S’s Justin Norris.
