Corvette chief engineer Tadge Juechter recently acknowledged, "A mid-engine layout is something we consider for every new generation." What he didn't say is that, after six months of intense engineering effort, the mid-engine Chevrolet Corvette is dead. Again.
But not totally. In 2010, General Motors will strive for outright victory at the 24 Hours of Le Mans. GM's racer will be a Corvette conforming with the LMP1 (Le Mans Prototype) Evo rules that will govern the seventy-eighth running of the world's toughest and most prestigious endurance race (see sidebar). This Corvette will be powered by a V-8 engine positioned behind the driver, just ahead of the rear wheels. Selling on Monday what you race on Sunday is the cardinal rule that prompted Juechter's 2007 investigation of a mid-engine production Corvette.
Half a century ago, Corvette patron saint Zora Arkus-Duntov became obsessed with the idea after his experimental SS racer nearly cooked John Fitch at Sebring. Arkus-Duntov explained, "The Corvette SS we raced had a front engine and a magnesium body. If a suspension bushing had not failed, sidelining our effort, the heat from the engine and exhaust would have fried the driver. It was then that I switched my mental gears to mid-engine to get rid of this huge heat generator at the front of the Corvette."
Arkus-Duntov spent the next seventeen years investigating mid-engine cars for racing, for production, and to entertain his insatiable need for speed. Four successive Corvette chief engineers have borne the same cross.
Why all of GM's horses, men, and women can't drag a mid-engine Corvette into production is a sob story for another day. As solace, we offer this early look at the front-engine Corvette you will be able to buy in 2012.
Take our graphic depictions with a few grains of salt. No refunds will be issued in the likely event that these artistic expressions penned by the senior design class at Detroit's College for Creative Studies do not pan out. A dead accurate look at the next Corvette is impossible, because GM designers are still sculpting their curly cues and character traits. We can only hope that these student illustrations inspire the GM pros to greater heights.
Our preview of the C7's mechanical makeup rests on firmer footing. To gather these insights, we conspired with Peter DeLorenzo, founder and publisher of the Autoextremist.com Web site. This influential Detroit-based thorn in the auto industry's side has the tightest net of loose-lipped inside sources money won't buy.
Last December, President Bush signed a corporate average fuel economy (CAFE) standard into law that will eventually require every maker's car fleet to average 35 mpg or more. This doesn't mean we'll soon be driving 35-mpg Corvettes. Nonetheless, it's a long, steep road to 2020, and the next Corvette will have to exceed the 18-19 (combined) mpg offered by C6 models. Heightened efficiency will be achieved by the usual means: less weight, smaller engines, and reduced friction and aerodynamic drag. A hybrid powertrain is a possibility, but probably not before C8 arrives.
Juechter's boss, vehicle line executive Tom Wallace, who's responsible for all of GM's performance cars, has begun hinting that the C7 will be hundreds of pounds lighter. Shedding 200 pounds from a Z06 or 300 pounds from the standard Corvette coupe will move them below the 3000-pound barrier. (Think Porsche Boxster/Cayman.) Some of the weight savings will come from modest length, width, and wheelbase snipping. Use of ultralight materials, a longstanding Corvette pursuit, will trim more mass.
Consider a few examples: Substituting titanium for stainless steel in the 2001 Z06's exhaust system saved nineteen pounds. The shift from steel to aluminum for the 2006 Z06's hydroformed spaceframe dropped 137 pounds. Molding the ZR1's hood, front fenders, and roof skin in carbon fiber trimmed more than thirty pounds. According to Juechter, carbon-fiber doors and rear fenders would save another twenty pounds. The ZR1's carbon-ceramic brake rotors cut rotating, unsprung, and curb weight while also benefiting fade resistance. Significantly narrower tires and wheels also would subtract worthwhile heft.
GM Powertrain engineers have investigated cast magnesium transmission cases - a material already used for the Corvette's front subframe and roof reinforcement - because it's relatively affordable and one-third lighter than aluminum. Cast magnesium wheels were a Corvette option for seven years until comparable weight savings were realized with spun-cast aluminum. While a magnesium cylinder block is an ambitious leap, BMW has converted portions of its 3.0-liter six to this material. It only costs money, and in this business, the more you spend, the more you save.
The beauty of reduced curb weight is that it benefits both mileage and every facet of performance. But don't count on any acceleration gains, because the next Corvette surely will be powered by smaller (4.5- to 5.7-liter) engines. Luckily, the rest of the underhood news is good. There's no chance that the cylinder count will deviate from the current eight-pack, because keepers of the Corvette flame insist that a V-8 is vital and not eligible for sacrifice to the gas-mileage gods. ...next page >>