Numbers printed on paper is one thing, and the visceral sensation of driving a diesel-powered hot rod is another thing entirely. As someone quite well versed in dropping the hammer in fast muscle cars, Mike reports that the diesel experience is like nothing he's encountered before. "Driving this car is very weird and very different from anything else out there. Even without any mufflers, it's very quiet and sounds just like a stock Chevy truck at idle," he explains. "When you first get on the gas, it sounds almost like a gasoline V-8 that's misfiring, then it quiets down again as the boost builds. The Duramax only turns 4,200 rpm, so the power hits real hard. The motor never feels stressed at all and it just kills the tires. It's way faster than any 10-second car I've owned, and when I get a chance to run it at the track, I'm sure it will run 9s easily."
With the magnitude of fabrication that goes into a project like this, there's no getting around the fact that it's going to cost megabucks. That said, credit must be given where credit is due, and Mike's hands-on aptitude is right up with the most down-and-dirty of enthusiasts. He tackled most of the bodywork himself, built a custom showcar-caliber interior, assembled the motor, ported most of one head before running out of steam, stitched together the custom intake manifold, designed the intercooler and cooling systems, plumbed the oil and fuel lines, ran the wiring, and completed the final assembly all in his garage. The wiring and plumbing alone took six months to finish. "One of my favorite cars is a Chevelle I built a long time ago with a 509 big-block that runs 10s. It's a nice car, but anyone can build something like that," Mike opines. "Not only is this Duramax project different, it's very difficult to pull off. That's why I don't think a swap like this will catch on. Most people probably wouldn't have the time or patience to do it."
Even with the Duramax, rollcage,...
Even with the Duramax, rollcage, and an extremely heavy Allison five-speed trans, the Chevelle weighs in at a reasonable 4,400 pounds, which is just a hair more than a new Cadillac CTS-V. Mike hates the look of small rotors behind big wheels, so while it doesn't do much for performance, he fit 16-inch rotors out back. Anaheim Prestige (Placentia, California) laid down the Mist Turquoise paint.
Maybe that's a comment the hot rodding public will perceive as a challenge, or maybe it's just words of wisdom from a man who's been there, done that. Either way, if it spawns more diesel-powered muscle cars, we won't complain. One thing's for sure--truck-based diesels have what it takes to go toe-to-toe with conventional big-blocks and embarrass them in the torque and mileage departments. Whether compression ignition trumps spark ignition is a debate for another day, however, because after just watching and smelling the Duramax Chevelle annihilate its 33x22 Mickey Thompson's, we're getting kind of hungry. Hey Mike, do you think you can get a McDonald's sponsorship out of all this madness?
Diesel To The MaxFrom a performance standpoint, the fundamental design of a diesel has significant advantages that gasoline engines just can't touch. Unlike a gasoline engine that relies on fuel and ignition spark for combustion, diesels operate on the principle of auto ignition. In lieu of spark plugs, the extreme cylinder pressure and heat produced by a diesel's extreme compression ratio (between 17:1 and 20:1) initiates the combustion process. This is part of the reason why diesels aren't very picky about the type of fuel you dump into them. (Banana peels anyone?) Detonation beats up bearings, pops head gaskets, and blows holes through pistons, but without ignition spark, diesels live in a world where harmful detonation doesn't exist. Combine all this with a turbocharger and the result is tremendous bottom-end torque. GM's latest 6.6L Duramax cranks out 660 lb-ft at 1,600 rpm to go along with its 365 hp. Since diesels aren't limited by octane like gasoline engines, they can handle enormous boost pressures, making them exceptional performance platforms. According to the diesel specialists at Pacific Performance Engineering (www.pacificp.com), an upgraded turbo, basic fueling upgrades, and a 4-inch downpipe on a stock Duramax will make 800 hp and 1,600 lb-ft. In addition to gloriously swollen torque curves, diesels offer far better fuel economy as well. While gasoline engines operate at a 14.7:1 air/fuel mixture, diesels are lean-burning machines that run 20:1 mixtures under normal driving and as lean as 60:1 at idle. Needless to say, the potential is there for phenomenal performance and fuel mileage.
GM's Duramax line of V-8 diesels was introduced in 2001, and is the product of a joint venture with Isuzu. Over the years, it has earned a reputation for excellent reliability and stunning power potential. The Duramax has been regularly updated with minor revisions every few years, at which time it's been re-labeled with a different designation (LB7, LLY, LBZ, LMM). Each variant is very similar and an equally capable performance platform. All 6.6L Duramax diesels feature a 4.050-inch bore, a 3.900-inch stroke, an iron block, aluminum heads, and direct common-rail injection. Their internals are forged, and compression ratios vary between 16.8- and 17.5:1. Although the camshaft is mounted inside the block, the Duramax has a forked rocker arm design that enables actuating four valves per cylinder. Like all modern turbo diesels, the Duramax operates at extremely high fuel pressures of up to 26,000 psi. The going rate for a used Duramax complete with a computer, wiring harness, and Allison transmission is about $7,000. Although some will make the argument that they technically aren't big-blocks, Mike Racke reports that the Duramax is very similar in size and weight to a Rat motor and even has the same bellhousing pattern. However you choose to label them, there's no disputing that diesels aren't just for trucks anymore.
The fuel system of a Duramax...
The fuel system of a Duramax relies on a lift pump that pushes fuel from the tank, or cell, to the front of the car at roughly 6 psi. From there, a gear-driven injection pump mounted in the lifter valley feeds the injectors by cranking up the pressure to about 26,000 psi. In addition to an aftermarket PPE lift pump, the Chevelle has a second injection pump that's driven off the crank pulley. Fast Eddie's built the custom cell.
For hood clearance, the motor...
For hood clearance, the motor was mounted as close to the ground as possible, which required reducing the stock oil pan height by cutting it. The alternator, A/C compressor, and secondary injection and power steering pumps are all mounted off of custom brackets and hidden under the turbos.
One of the most impressive...
One of the most impressive home-built pieces is the custom intake manifold. Mike started with a -inch aluminum plate for the base, cut the dual plenums out of 3.5-inch aluminum pipes, then carefully grafted 16 intake runners out of aluminum stock. He figures that the whole setup cost him only $30.
Almost every part of the interior...
Almost every part of the interior was custom made by Mike. For the dash, Mike cut two original SS pieces and fused them together with fiberglass and foam. A satellite navigation screen sits where the heater controls and center air vents used to be. The Auto Meter gauges have been re-screened to match and blend in with the stock Chevelle gauges. Other highlights include a suede headliner, Recaro seats, and an Alpine stereo.