Mikie Carrasco’s record-setting, full interior, 8,000-pound 4×4 Silverado is further proof the L5P is the toughest Duramax ever produced.
How tough is the L5P Duramax from the factory? For the last five years, Mikie Carrasco’s ’18 Chevrolet Silverado 2500 HD has been turning out four-digit horsepower. Some 60,000 miles into this half-decade beatdown, his late-model GM V-8 continues to handle the abuse without issue. In fact, it’s helped Mikie set (and then reset) quarter-mile and eighth-mile records for the L5P platform. Last spring, the full interior, crew cab Chevy coined “Black Nasty” stormed through the 1320 with a 10.11-second record-setting effort at 132 mph. On the same pass, the eighth-mile record—a record Mikie had already set a few weeks prior—was reestablished with an ET of 6.51 seconds.
But this story is much more than a tale of someone throwing gobs of fuel, a big single turbo, and a healthy shot of nitrous at an engine. It’s about pushing the limits of the L5P while simultaneously keeping it in one piece. That means finely tuned, spot-on calibrating, running high-quality parts, and making sure everything plays well with each other. And don’t forget the built Allison 1000, which is somehow surviving life in an 8,000-pound truck producing 1,500+ lb-ft of torque. What follows is the recipe behind the world’s quickest and fastest factory internal L5P Duramax.
There isn’t much to talk about beneath the intercooler piping, the big single, and the hood stack. Rather, it’s yet another example of a completely stock L5P Duramax doing L5P Duramax things—holding up to extreme horsepower, 4,000 rpm or more, and big torque. This particular version, owned by Mikie Carrasco, happens to be the quickest and fastest factory internal L5P Duramax in existence at the present time. Its only mods include ARP head studs in place of the factory bolts. The fact that it’s lived through 60,000 miles of abuse (all while making 1,000 hp, or more) is a testament to the highly refined, torque-limited tuning offered by All In Truck Performance—home of the highest horsepower stock long block L5P.Thanks to a Wehrli Custom Fabrication S400 single kit, complete with a T-4 pedestal and 3-inch hot and cold-side intercooler pipes, a Forced Inductions GTR 42/80 sits in the valley. A dual ball bearing charger, it boasts a billet, 80mm compressor wheel within the polished compressor housing you see here, and an 85/93mm turbine wheel inside a 1.25 A/R exhaust housing. The factory up-pipes and exhaust manifolds are still in play, and Mikie says the turbo produces roughly 60 psi of boost at full tilt. Hidden from view, a covertly routed Nitrous Outlet system adds a few hundred horsepower to the truck’s bottom line.Back by the factory fuel tank, an AirDog II-5G system is tasked with sending low-pressure fuel to the engine. The 220-gph system has no problem ensuring ample volume and pressure are always on tap for the CP3 to use. Speaking of the OEM tank, its 36-gallon capacity not only allows Mikie to daily drive his Silverado but take it on long trips—and the truck returns surprisingly respectable fuel economy. Believe it or not, even in its high-horsepower state Mikie can make it from Carlsbad, New Mexico to Indianapolis on two tanks of fuel. Not bad for having 1,300-plus hp on tap.For what is arguably the most vital piece in the 10-second puzzle, Mikie—through his friends at All In Truck Performance—got a helping hand from the common-rail fuel system experts at Exergy Performance. First things first, the factory Denso HP4 high-pressure fuel pump was replaced with an LBZ-based Bosch CP3, which is of the 14mm variety. The stroker pump supports a set of Exergy built-to-order injectors with internal body mods and EDM’d, 200-percent over nozzles. These are some of the highest flowing Denso-based L5P injectors on the market at the present time—but Mikie is ready to go even bigger when higher flowing units become available.Squeezing upward of 1,500 lb-ft of torque through an Allison 1000 isn’t easy, but to bulletproof the six-speed automatic as much as possible (and ensure its shifts are as crisp and quick as they can be) Mikie turned to All In Truck Performance. In AITP’s care, the Allison was treated to billet input, intermediate and output shafts, along with a billet P2 planetary and C2 hub. A J model, extreme clutch, triple disc torque converter from Goerend Transmission handles power transfer. It’s graced with a billet stator and, to complement the big single turbo, boasts a stall speed that checks in somewhere between 2,700 and 3,000-rpm.You’re looking at more than just the late-model Silverado’s factory leaf springs here. Incredibly, and even at 1,300hp, there are no traction bars on the truck. The rear AAM has been fitted with a locker, however. Up front, the OEM tie-rods have been upgraded to eliminate flexing and toe-in, toe-out scenarios during boosted, four-wheel drive launches. Additional reinforcement of the AAM 9.25 IFS comes in the form of DHD’s center link steering stabilizer bracket, which transfers load away from the center link, thereby ruling out any erratic steering behaviors when racing. A Fox Performance Series 2.0 IFP shock can be found at each corner.For daily driving or 7.70 Index racing, Mikie’s Silverado rolls around like this, with 305/50R20 Toyo Proxes ST III’s mated to 20-inch Steel Off-Road Revolt wheels. But when it’s time to run all-out, the all seasons get traded in for a set of P325/45R18 Hoosier drag radials mounted to lightweight, 18×10-inch Moto Metal M0970 wheels. The latter combination was bolted to the truck when it set the new L5P high marks—10.11 at 132 mph in the quarter-mile and 6.51 at 108 mph through the eighth.You don’t see a lot of L5P’s with hood stacks. And if you do, they usually aren’t daily drivers. But that didn’t stop Mikie from pursuing the look he was after (no, it wasn’t done to make routing the downpipe and exhaust easier). Jorge’s Speed Shop in Seminole, Texas handled the job of cutting the hole and fabricating the 4-inch section that bolts to the back of the turbo. Aside from the hood stack, the truck is a full-on sleeper, with very few people likely to suspect the ¾-ton crew cab Chevy is capable of running low 10s.With the Hoosiers in place, the big tune loaded, the transfer case in 4-High, and 20 to 25-psi worth of boost on tap, Mikie’s Silverado leaves hard, often cutting high 1.5-second 60-foots. Strapped to the SuperFlow chassis dyno at All In Truck Performance, the truck has made 1,311-rwhp. At the drag strip, and with a best trap speed of 134.93 mph, the calculator puts him in the 1,380hp range. Regardless, this is one of the most powerful streetable L5P-powered GM’s—and as of right now it’s the fastest.This is the timeslip that documents Mikie’s record-setting pass, in both the quarter and eighth-mile. Note the 1.58-second 60-foot (he’s been 1.57), the 6.51 at 108 mph in the eighth-mile (record), and the 10.11-second quarter-mile at 132.78 mph (record). A few weeks before this pass, the truck trapped the 134.93 mph mentioned earlier, although its 1/8-mile and ¼-mile ET’s checked in a tad slower (6.64 and 10.28, respectively). Of course, these record passes were made at Hobbs Airfield Speedway, a track that sits in 3,700 feet of elevation. Mikie’s father Michael believes the truck is capable of running at least two tenths quicker at a track like Texas Motorplex in Ennis, which sits at 500 feet above sea level. If they make that 500-mile trip this summer, chances are pretty good Mikie’s 8,000-pound, stock long block L5P will go high 9’s.
