Competition Diesel Engines
Innovation Takes Oil-Burning Powerplants to 3,000 hp and Beyond
Innovation takes oil-burning powerplants to 3,000 hp and beyond
IT MAY BE hard to believe, but there was a time when making 500 hp was unbelievable performance for diesel engines. Fords had 180 hp in the late-’80s and early-’90s, Dodges were at 160 hp, and GMs were leading the pack with 215 horses. Sure, all of those engines could be modified, but upgrades for improved performance usually yielded only 50 to 70 hp.
The roots of modern diesel performance are traced back to the ’80s and sled pulling with oil-burning tractors. Even back then, tractor engines were fitted with compound- turbocharger setups that made nearly 200 psi of boost and cranked out 1,500 to 2,000 hp. And it wasn’t long before this technology was adapted to pickups.
In the late-’90s and early-’00s, Jeff Prince, Keating Shelley, Scott Bentz, Richard Madsen, Jeff Garmon, and Dan Scheid all tried compound-turbo setups on diesels, and as boost rose, so did power—from 500 hp to 800 hp, then finally beyond 1,000 hp. In the West, Gale Banks had his own ideas and was experimenting with a Cummins-swapped Dodge Dakota land-speed truck that made good power—cleanly—and set an FIA record at 217 mph. Things were starting to change. Diesels still had incredible torque, but now they made great horsepower too.
Diesel-powered vehicles, mostly trucks, are used in three primary categories of competition: dyno (often dual-purpose street trucks), drag racing, and sled pulling. When Diesel Power first hit newsstands in 2005, the engines that powered these vehicles looked a lot different than they do today. At that time, the top dyno competitors were making about 1,200 hp with stock blocks, crankshafts, rods, and
pistons; 13mm injection pumps (mechanical) or twin stock pumps (common-rail); and either medium-sized single or small compound turbos. Oh, and about three stages of nitrous oxide, too. Drag racing was small-time, with many drivers having success because their opponents’ trucks would break or simply because they were able to make a clean pass. Having the most power did not guarantee victory.
Of the three disciplines, sled pulling was the most advanced in the early days, as the top pullers were making 1,500-plus horsepower, using mostly stock parts and Holset turbochargers from engines in semitrucks and tractors making 100 psi of boost.
Eventually, advancements in technology brought change to diesel-engine performance. Injection pumps grew from 12mm to 13mm and 14mm, and then even a 16mm Sigma pump. CP3 pumps were modified to flow more, and using two augmented pumps became the norm. Turbos also got larger. Originally, a 57mm and 66mm compound-turbo setup was a hot all-around combination for power and towing, but that evolved into the 66mm ’charger becoming the small turbo in a 66mm/80mm compound package. Engines progressed, too, as filled and sleeved blocks became the standard for high horsepower. Aftermarket rods became available and stronger pistons were introduced.
Richard is one of the trailblazers in the dyno segment, as he built engines that, using fuel only, could match the 1,200 hp of the nitrous trucks. Scott and Dan prepared dragsters that covered the quarter-mile in 7 seconds, as did Gale with a tube-chassis Chevrolet S10 that ran so clean many thought its 6.6L Duramax engine was burning diesel methanol (it wasn’t). Sled pullers eclipsed the 2,000hp mark with engine combinations that were more refined and reliable, even with larger turbochargers.
Which brings us to today. If there was a motto for modern diesel engines, it would be, “Anything is possible.” Competitors in all three styles of competition now use aftermarket blocks or deck-plate engines (powerplants with a steel plate incorporated into the top of the engine block, so it doesn’t crack or rip apart). Cylinder heads flow more than 300 cfm, and blocks are prepped for roller camshafts. Engines are set up with three, or even four, modified CP3 pumps, and 16mm mechanical pumps are commonplace.
On the chassis dyno, making 1,000 to
“The roots of modern diesel performance are traced back to the ’80s and sled pulling with oil-burning tractors. Even back then, tractor engines were fitted with compound-turbocharger setups that made nearly 200 psi of boost and cranked out 1,500 to 2,000 hp.”
1,200 hp is a thing of the past. The once-unfathomed 2,000 hp might now be only in the Top 5 nationwide. Drag racing has progressed both mechanically and electronically to a point where dragsters are in the 6-second zone, while Outlaw Diesel Super Series Pro Street and National Hot Rod Diesel Association Super Street trucks make 7- and 8-second passes in the quarter-mile. According to sled pullers we spoke with, their engines’ 3,300 hp is produced with ease. Interestingly, we can’t pinpoint a component or system in diesel engines that has advanced more than others;
“If there was a motto for modern diesel engines, it would be, ‘Anything is possible.’”
rather it’s been improvements in all areas that give diesels a high rank on the performance ladder. Diesel-engine performance now rivals that of gasoline-burning powerplants, as aftermarket parts are numerous and widely available.
Improving traction is the new challenge. Trucks are spinning their tires on the dyno’s rollers, breaking parts at the dragstrip, and losing traction on the sled-pull track. Putting that in perspective, a modern 3,000hp puller might be at full power for only 3 or 4 seconds in the middle of the run, and for the rest
of the trip completing a pull truly depends on a driver’s skill.
So, what does the future hold for competition engines? Progression in all areas is almost certain, with higher rpm ceilings, more power, and stronger engines overall. One thing we haven’t seen yet—and feel is coming—is engines built specifically for using copious amounts of nitrous oxide (1,000 hp or more), and three-stage turbo systems producing 200 psi or more. As radical as they are now, diesel engines still have room to improve. We can’t wait to see what the future holds.
Aftermarket aluminum engine blocks are now readily available for Cummins engines. This block from Scheid Diesel Service is sleeved and designed to handle more than 2,500 hp for many seasons of sled pulling or drag racing.
Crankshafts, rods, and pistons for diesel engines have evolved over the years. Forged pistons like this Diamond Pistons slug are must-have pieces for the most extreme race engines, regardless of brand.
Wagler Competition Products has stepped way up with its Duramax engine program, and it now offers a 500ci DX500 engine that is capable of more than 3,000 hp.
While Ford’s Power Stroke diesel engines aren’t the most poplular powerplants in the sled-pull scene, several competitors use P-pumps on 7.3L engines built by Hypermax. Using the Cummins injection pump is believed to give the Ford engine an advantage over Cummins powerplants, thanks to the block’s two extra cylinders and the pump’s additional plungers.
Triple turbochargers are the new normal for peak performance in drag racing, sled pulling, and dyno testing. The concept is simple: Two turbos blow into one, which makes boost levels of 150-plus psi possible, all while reducing drive pressure and increasing overall efficiency.
Horsepower is rising in virtually all areas of diesel performance. At 2017’s Ultimate Callout Challenge, Jesse Warren’s ’08 Ford F-250 posted an insane 1,758 hp on a chassis dyno with an HEUI-equipped, 6.0L Power Stroke engine.
One nice thing about common-rail injection is that more injection pumps can be added whenever necessary (rail pressure typically dictates need)! Kyle Michael’s “Climax” Super Stock puller has a geardriven, 4-CP3 fueling system.
Standalone ECMs, like this Bosch Motorsports processor, are becoming more and more popular for Cummins and Duramax engines, thanks to the near-infinite amount of tuning adjustments that can be made with the devices.
After water-injected sled-pull engines picked up more than 200 hp with an intercooler, the device became standard fare. Water-to-air intercoolers are excellent at reducing intake-air temperature and aren’t as susceptible to ambient-air temperature changes as air-to-air units are, thanks to large ice-water tanks.
Scheid Diesel Service now builds a 16mm injection pump for competitors who want to make insane power. The big fueler flows more than 1,500 cc and can support more than 3,000 hp. Injectors are built to match and can be up to an enormous 5x0.039 inches in size.
Nitrous oxide is still a good power-adder. Serious nitrous systems can add another 300 to 500 hp to engines that already produce 1,500 to 2,000 hp or more.
Competition diesel engines have all-out oiling strategies. Large capacity, multistage dry sumps keep oil clean, cool, and properly pressurized.