The Minus Max: Smart-Built 600-HP 2500HD

When it comes to building a diesel truck, most enthusiasts follow the “more is more” approach, with huge turbos and injectors, multiple pumps, and usually a lot of heat and smoke. In the diesel industry at least, it’s not often that you get someone who builds a fast truck with the least amount of parts possible. But that’s exactly what Kirkville, Iowa’s Alex Hynick did.

To be honest, it helps that his brother AJ owns a diesel performance shop called Hynick Diesel. That enabled him to sweep up a wounded ’04.5 Chevy 2500HD for dirt cheap. As it turned out, the 240,000- mile truck ended up breaking a crank, which meant a full engine rebuild.

BUDGET MINDED

It’s easy to spend a lot of money building an engine, but Hynick was on a budget, which meant using as many stock parts as possible. Still, the team performed a few clever upgrades along the way. A new LLY block and crank were found, but the rods were upgraded with stronger LML units, as were the pistons. The cam and crank were also keyed, both the mains and heads were upgraded with ARP hardware, and the heads received TTS valve springs.

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COMPOUNDED

Alex really took a different route than most when it came to making power. He figured he’d need a turbo upgrade anyhow if he wanted much past a hot 500 rwhp, so he decided he might as well just go straight to compound turbos. As it so happened, he was able to snag a Garrett GT45-based turbo with a Precision Turbo wheel and front cover from his brother’s pulling truck, which was used to build a custom compound turbo setup. All of the piping was done by AJ, and the setup cranks out a healthy 55 psi of boost.

Ultra-quick turbo response is available in the form of the factory Garrett turbocharger, which was retained from the original 240,000-mile engine. Custom tuning helps it lead a long life while still providing plenty of low-end oomph.

Even with a stock CP3 pump and factory injectors, Alex Hynick’s Duramax cranks out more than twice its stock power rating, thanks to twice as much boost. Checking in at
about 55 psi, the engine makes an estimated 600 rear-wheel horsepower based upon weight and track times.

Part of the reason the Chevy’s 60-foot times are so awesome is the four 305/50R20 Nitto 420S tires that hit the ground when the truck hits the street or the dragstrip. The wheels are 20×9 Kranks from Fuel.

The bigger of the two turbos is an old Precision Turbo unit that was built based upon a GT45 frame with a 80mm inducer. The large turbo compresses air and sends it into the smaller one, which then sends it into the engine.

Alex’s brother AJ built the Kawasaki Green compound kit that helps the ’04.5 LLY make its steam. The compound kit was built using an AFE dry filter, and was also designed to keep the battery and overflow in the engine bay rather than relocating them elsewhere.

There’s a LMC Truck rollpan out back, so one might think the owner doesn’t tow with this Chevy. When you look in the bed, there’s still a big gooseneck hitch that proves otherwise.

Exhaust is as simple as it gets, with a chrome stack right behind the cab. From underneath, the 4-inch exhaust leads straight into the stack, which measures in at 5 inches.

The heat-wrapped exhaust takes a clean route from the smaller turbo to the larger one before exiting the engine bay. The downpipe for the big turbo was kept on the small side (3.5 inches) for clearance, but widens to 4 inches underneath the truck.

The basic no-frills interior says “work truck,” as Hynick still uses his truck quite often for daily chores. Since these photos were taken, he’s installed an Edge CTS2 monitor to better keep track of the vehicle’s performance.

To complement the turbos, a better flowing driver-side exhaust manifold from LML was installed, along with a set of Pro Fab up-pipes. An old used and abused PPE lift pump was installed, along with a custom EFILive tune from Hynick Diesel Performance. The injectors, CP3 pump, and the rest of the engine remain stock.

BACKING UP THE POWER

With the engine now cranking out an estimated 600 rear-wheel horsepower, the factory Allison 1000’s life would be short-lived, so it too received an upgrade. Again, A.J. helped out with the build, freshening and strengthening the stock transmission in order to handle extra power. He also installed a converter from Goerend Transmissions, did custom TCM tuning, which he credits for helping the transmission live, along with generating ultra-hard launches at the drag strip. The high-mileage transfer case also received some attention, as a pump-rub kit from Kennedy Diesel was installed.

DMAX SHUFFLE

Speaking of racing, Hynick didn’t want his hot new ride to be a show queen, so he took all the steps to ensure he could make as many 4×4 launches as he wanted. After flipping through the Cognito catalog, he ordered a set of heavyduty tie-rods, along with upper control arms, and pitman and idler arm braces. Surprisingly, the factory rear suspension received no such treatment, but the fronts of the leaf springs are clamped for drag racing. A 4-inch steel driveshaft was installed after the factory aluminum unit broke during a sled pull, and a helicalgear locker was fitted to the 3.73-geared rear end.

IN THE END

Using a careful selection of modifications, Alex has built a truck that’s not only reliable, but faster than one might think. With a stellar best 60-foot time of 1.61, the truck has rocketed off to a 7.74 at 87.5 mph in the eighth-mile, which equates to low 12s in the quarter. Combine that with the fact that the truck is no lightweight (it still has a gooseneck hitch) and its mellow 1,300-degree EGT readings, it’s clear that sometimes when it comes to building an awesome all-around ride, less really is more. DW

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Pinaki Bhattacharya

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