Competition Diesel Performance Truck Tires, Part 1: Why The Pros Choose Nitto
For years we’ve seen Nitto tires outperform the competition across the diesel spectrum. From the street to the drag strip and the chassis dyno to the pulling track, Nitto’s comprehensive light truck line thrives in every form of diesel motorsports, as well as daily driving and towing duties. At U.C.C. 2022 we watched competitor Chris Patterson campaign a set of NT555 RII drag radials on the chassis dyno—and then swap over to the ultra-aggressive Mud Grappler for the truck pull. A Fourth Place overall finish in one of the most grueling 3-day torture tests a truck can be subjected to was the result.
For his highly-fueled, triple-turbo’d and nitrous-fed 6.7L Cummins—a setup that’s produced an incredible 3,089 hp at the rear wheels—utilizing tires that maintain traction is paramount. To get the full scoop behind his tread(s) of choice, we caught up with Patterson to see why he trusts Nitto tires to get the job done both on and off the pavement.
Most car enthusiasts would likely associate Nitto’s NT555 RII D.O.T. drag radial with Mustangs, Camaros and the like, but Chris Patterson loves the way they help his ’07 Dodge Ram 3500 hold the road. And on the street, there are six triple-nickel RII’s under the truck. In dyno trim, two drag radials get the nod (likely to minimize the drag that comes with leaving the dual rear wheels in place). The 305/50R20 version shown above measures 32.05-inches in overall diameter and 12.44-inches in overall width.
In the past, the NT555 RIIs allowed his fire-breathing crew cab Dodge to dyno an insane 3,089 hp.
Why Chris Likes The NT555 RII: “It features a hard sidewall that flexes, but doesn’t balloon and expand like other tires in its class, which is perfect for the dyno.”
NT555 RIIs On The Street
While the NT555 RII’s have excelled on the dyno, Chris has yet to apply that kind of power on the street. However, the truck’s mildest tune—an ECM file that still provides for 1,740rwhp to be made—is fairly manageable on the street, so long as 4-Hi is selected in the transfer case. ”When I drive the truck on the street I only use about 50-percent throttle,” Chris tells us. For those that have a hard time comprehending what 1,700rwhp (and 3,000 lb-ft of torque) feels like on a public roadway, that’s probably a safe thing for Chris to do. As for longevity, Chris tells us he’s racked up 2,000 trouble-free miles on the NT555 RIIs so far.
Triple Turbos, Triple-Digit Boost
Does your turbo have turbos? Chris’s 6.7L Cummins does. And in his case, triple-turbos mean triple-digit boost, with 110-psi being crammed into the engine at full tilt. Up top, two identical 76mm S400-based turbos from TDI serve as one giant atmosphere unit. Down on the exhaust manifold (beneath the two S476 units pictured here) sits the primary charger: an 83mm S400 with a 96mm turbine wheel and a 1.15 A/R exhaust housing from VS Racing. The two-stage triple-turbo arrangement was on the engine for Chris’s 2,614hp performance at U.C.C., but he believes his other system, a two-turbo compound arrangement, makes more power. In that turbo configuration the dual S476 chargers are replaced with a massive 106mm turbo from VS Racing.
Mud Grapplers For The Dirt
In truck pull trim, the NT555 RIIs are ditched in favor of a tire more suited to off-roading: Nitto Mud Grapplers. As we’ve seen throughout diesel truck pulling over the past 10 years, Nitto’s extreme mud terrain is right at home in the dirt. We’ve also observed that it really shines on looser tracks, which is the type of track Chris encountered at U.C.C. 2022. The 35x12.50R17LT Mud Grappler shown here measures 34.84-inches in overall diameter and 13.19-inches in overall width. Aside from their aggressive tread blocks, they’re also an E load range tire with a load carrying capacity of 3,640 pounds apiece, making them the perfect DOT tire for truck pulling.
6 Tires & Plenty Of Bite
With the transfer case locked in 4-Lo, Chris hooked to the sled and, once the official waved the green flag, left with the 48RE in second gear. After locking the converter he grabbed third gear, and once he hit the rev limiter he went ahead and shifted into Overdrive. Near the end of the pull, Chris unlocked the converter while leaving the transmission in Overdrive. In hindsight, Chris told us he should’ve left the converter locked and downshifted to third instead. When we asked him if he used any nitrous during the pass he answered “Oh hell yeah! I had two big kits on the button.”
Beefed Up Axles
To keep the truck’s factory-based axles from destructing under the stress of a 40,000-pound sled, hard-biting traction from 35-inch Mud Grapplers and from (potentially) seeing 4,000 lb-ft of torque from the engine, both the front AAM 925 and rear AAM 1150 were treated to upgrades. All of the additions came from Yukon Gear & Axle and include heat-treated 4.10 ring and pinion gear sets, chromoly axle shafts and a Grizzly locker. Both axles remain settled throughout the course of a pull (and on the track or street, for that matter) thanks to front and rear four-link suspension systems with QA1 double-adjustable coil-over shocks.
4th Place Overall U.C.C. Finish
At go time, the Mud Grapplers did exactly what they were supposed to, they allowed Chris and his Dodge to dig their way out to a 274.58-foot distance on the loose, fairly dry track. When all 45,000 pounds came to a halt for Chris and his Dodge at U.C.C. 2022, the green dually wound up ninth out of 15 trucks—but when you consider the fact that he was primarily up against purpose-built pullers (not the same trucks that’d been campaigned on the dyno and at the drag strip in the days prior) it’s much more impressive. Less than 48 hours before this photo was taken, the same truck was running mid 5s in the eighth-mile.
Select photography provided by Levi Millerborg (@lm_diesel)
More From Driving Line
- For the full scoop on what went down at U.C.C. 2022, check out our 3-part event recap series starting here.