1000hp concept....13.6 liter v16.uuughh
DETROIT — With the goal of moving the Cadillac brand farther upscale, General Motors will test the waters this auto show season with an audacious 1,000-horsepower supercar concept introduced Sunday at the Detroit Opera House in conjunction with the North American International Auto Show’s press preview. Powered by a 13.6-liter (828-cubic-inch) V-16 engine, the sporty four-door makes last year’s 12-cylinder Cadillac Cien concept seem like a quaint idea.
“Our dream was to create a modern interpretation of everything that made Cadillac the standard of the world: striking design, obviously heroic proportions, remarkable technology and craftsmanship,” said Bob Lutz, vice chairman of product development and chairman of GM of North America. The resulting concept, called the Sixteen, is “a vision of the golden age of Cadillac to come,” he said.
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The project started more or less with the idea of a V-16 engine, to push the limits of street-legal power (and some would say decency) and to celebrate Cadillac’s heritage. The Fleetwood coach cars of the 1930s featured 16-cylinder engines, the first of which powered a 1930 Series 452 and the last of which rolled off the line in the 1940 model year.
The Sixteen concept and the engine, which is now called the XV-16, influenced each other’s development. The engine obviously needed a long engine compartment to live in, and Wayne Cherry, GM vice president of design, explained that his team designed the engine compartment as a showcase, “like a setting for a diamond,” with powered gull-wing hood panels. The aluminum spine where the panels meet became a design element that’s visible in the center when the hood is closed.
Thomas G. Stephens, group vice president of GM Powertrain, led the team that designed the all-aluminum overhead-valve (pushrod) XV-16. “The team designed, built and demonstrated a working engine in less than eight months,” he said. “That’s an incredible feat for an engine that is basically an all-new design with very few shared parts.
“At 695 pounds, the XV-16 is actually 64 pounds lighter than the [8.1-liter] Vortec 8100 V-8 in our full-size trucks and utility vehicles,” Stephens said. “Speaking to the engine’s elegance and simplicity, consider that even with twice the cylinders, it has fewer parts than any double-overhead-cam V-8 engine in the industry, and its front profile is significantly smaller than any double-overhead-cam V-6, V-8 or V-12 design. I point this out because it’s one thing to decide to create a 1,000-hp concept engine; it’s quite another to commit to getting 20 miles per gallon real-world highway fuel economy.”
The secret to the fuel economy is a three-step version of a technology GM plans to make standard in many of its V-6, V-8 and larger engines within the next few years: cylinder deactivation, which GM terms Displacement On Demand (DOD). Aside from the fact that an overhead-valve engine with a 90-degree V angle made the XV-16 lighter and more compact than an overhead-cam engine, GM only applies DOD technology to the simpler pushrod design. GM’s adherence to an engine style many consider outdated is what has allowed the automaker to make gains that would be more complex, expensive or simply impossible for a manufacturer of exclusively overhead-cam engines.
The three-step DOD allows the engine to run on four, eight or 16 cylinders — “four for cruising, eight for passing and 16 for just having fun,” as Stephens put it. Lutz later said in an interview with journalists, “This car, if it went from here to California, would run on four cylinders and 250 hp 30 percent of the time, 8 cylinders and 500 hp 60 percent of the time and run the remaining 10 percent with 16 cylinders, so the 16 would rarely operate.”
Though the engine’s fundamental design is simple, with two valves per cylinder, it includes some modern materials and technology, such as lightweight titanium-alloy valve springs and variable valve timing. Dual-overhead-cam engines have more valve-timing flexibility, but the XV-16’s single camshaft features electrohydraulically actuated dual-equal cam phasing, which offers some of the efficiency benefits and performs exhaust gas recirculation (EGR), a pollution control, in lieu of an external system.
Because of the XV-16’s prodigious torque — 1,000 pounds-feet to match the horsepower — it practically must be teamed to an automatic transmission, as it is in the concept. It’s a heavy-duty version of the 4L85E four-speed from GM trucks, though Lutz said he’d specify a six-speed were the car produced for sale. Asked if a manual transmission is even a possibility, Stephens said, “Oh, I wouldn’t even try.” The Sixteen has rear-wheel drive and electronic traction control.
Not based on any existing GM platform, the Sixteen is a new structure built largely of aluminum with the assistance of Alcoa Automotive. Technically a space frame construction, the Sixteen has a central structural backbone rather than the exoskeleton used in Saturns. The exhaust system, driveshaft and control systems pass through this tubular spine. Cadillac says this aluminum approach weighs up to 50 percent less than a steel construction. Despite this, and extensive use of aluminum elsewhere — in the body panels, transmission case, driveshaft and engine — the 18.6-foot-long car weighs roughly 5,000 pounds.
The four-wheel-independent suspension comprises a short-and-long-arm design in front and semi-trailing arms in the rear. Four-wheel steering mitigates the car’s 140-inch wheelbase. Six-piston Baer brake calipers grab 16-inch discs, front and rear. The wheels are enormous, 24-inch polished aluminum fitted with custom Michelin tires.
Cherry becomes more emotive than usual when he discusses the Sixteen’s interior and exterior designs, emphasizing craftsmanship and attention to detail over and above materials, though the materials count, too. The seats are upholstered in hand-stitched Tuscany leather. Walnut burl veneer adorns the dashboard, center console and doors.
“The needles on the instrumentation and the Bulgari timepiece are etched on rotating crystal lenses,” Cherry enthused. The crystal continues on the car’s exterior, encasing the Cadillac wreath and crest logo on the grille and trunk lid. Both the headlights and taillights use LEDs, and both follow Cadillac’s Art & Science design movement, but the car is much softer overall, more organic than the earlier cars. It looks as if someone took a file to the hard edges and rounded them. Like the Cien — the best realized of the edgier Art & Science vehicles — the Sixteen is a far better sight to see in person than in photos.
It also turns out to be Cherry’s swan song. “Wayne Cherry will retire this fall,” Lutz announced to the media. “Wayne personally spent countless hours perfecting every nuance of this car, checking and rechecking, redoing surfacing and not stopping until he achieved perfection. To me it is without question the crowning achievement of his great career.”
Asked in an interview if the Sixteen superceded the Cien in the running for production, Gary Cowger, president of GM of North America, said, “Nothing’s ever off the table, but we looked at the Cien. It was a V-12, as you know, and that’s kind of why we did this one, to judge reaction between the two. The Cien was hugely popular. Our dealers loved it.”
Officials had suggested last year a price of $200,000 to $300,000 should the Cien be produced, but Lutz said the Sixteen’s price could be north of that. Cowger said, “Let’s just see what the reaction is, and we’ll determine where to put it at. It’s not going to be a high-volume car.”
Lutz said Cadillac would probably build as few as 500 to 1,000 units if the Sixteen got the green light. Asked how fast it could be ready, he said, “I think for a car like this, if we made a decision this month or next month, to be honest I think we’d be looking at four years because there’s so much new technology. We’ve never built an aluminum car this way. You’ll notice there’s no [BMW] i-Drive or anything like that because we don’t believe in making the interface with the driver more complicated than it has to be, so to drive and to operate it will be a very straightforward car, but it will have things like drive by wire and steer by wire and so forth. If we did anything like this car, it would have to be absolute perfection. We couldn’t ask our first customers to be our test drivers for us.”
The astute have noticed that a horsepower war has been raging at the auto shows and to a lesser extent in the market. There’s no telling how far this war will go, but with its 1,000-hp Sixteen, Cadillac has certainly won this battle.
