THE CHASSIS
Considering the dynamic strides achieved with the Z06, you might expect Corvette engineers to rest on their chassis laurels. You would be mistaken. While the hydroformed-aluminum spaceframe, rack-and-pinion steering, and core suspension components are for the most part carryover, the brakes, dampers, antiroll bars, wheels, and tires have all been upgraded for the ZR1's mission.
A practical rule of thumb is that braking capacity must rise in step with acceleration and speed potential. In accord with this non-Newtonian law, the ZR1 is upgraded with the Corvette's first carbon-composite brake system. The Brembo-supplied stoppers are described by Juechter as among "the largest carbon-ceramic rotors available on the planet." Measuring 15.5 inches in diameter in front and 15.0 inches in diameter in back, these radially and laterally vented discs were originally designed for Ferrari's FXX and Enzo, respectively. The Brembo monobloc calipers house six pistons in front, four in back.
Goodyear and Michelin periodically face off to see who deserves the honor of manufacturing the Corvette's footwear. Michelin won this go-round, so the ZR1 is shod in Pilot Sport 2 ZP (zero-pressure, or run-flat) tires, sized 285/30YR-19 in front, 335/25YR-20 in back. Twenty-spoke spun-cast Speedline aluminum wheels will be offered with a choice of a chrome or silver-painted finish.
The ZR1 also will benefit from larger-diameter antiroll bars and second-generation MR (magneto-rheological technology) dampers, which are said to be versatile enough to cover everything from flat-out racetrack lapping to smooth-road, civilian-speed touring. Juechter reports that the hardware and the software were both significantly improved for 2008.
THE BODY AND INTERIOR
Last year's comprehensive interior upgrade should nicely appease sniffy Corvette customers who will expect near perfection for their $100,000. That said, the leather-wrapped-everything package, which costs an extra $8005 in a 2008 Corvette, won't be tossed into the ZR1 for free. Juechter cites flexibility as the reason. "We're offering a fairly basic car for the track crowd and one option package with practically everything for more typical ZR1 customers," he says. For 2009 models, the high-zoot leather will be available in an expanded color palette.
About half of the ZR1's exterior panels are shared with the Z06, and the remainder switch to carbon fiber to save weight. The hood, front fenders, roof, and rocker extensions are all made of the stiff, light material to trim fat. Key pieces - the rockers, the splitter attached to the front fascia, the roof, and the B-pillar bow - are left unpainted to wow the rubes. According to Juechter, these are the auto industry's first visible carbon-fiber panels that won't yellow and crack over time due to ultraviolet light exposure. The breakthrough is a secret elixir costing $60,000 per gallon that, when added to the clear coat, blocks the harmful rays better than Bain de Soleil.
The cherry on top is a polycarbonate window - measuring roughly seventeen by nineteen inches - in the hood that provides a partial glimpse of the beast residing within.
Ready to rumble, the ZR1 should hit the streets weighing 3400 pounds or possibly a bit less, according to Juechter. The new Corvette king tops the Z06's power-to-weight ratio by about ten percent and the $270,000 Ferrari 599GTB's ratio by twelve percent.
THE BOTTOM LINE
We predict that Juechter's next presentation to his boss will prompt the GM equivalent of hugs and high fives. The ZR1 is another great addition to the Corvette's rich performance portfolio. To filch a thought from the chairman, we can only wonder what this team would do with a $150,000 price and permission to move the engine behind the driver.
In reviving the ZR1, GM taps into a storied - but no always glorious - past.
The new ZR1 might break new ground - it's the first Corvette to sport a factory-installed blower, the first to carry a gas-guzzler tax, and the most expensive Chevy in history - but the idea of an over-the-top, factory-built Corvette isn't new. Neither is the ZR1 name, which first appeared in 1970 as a $969 option for the base Vette, consisting of a 370-hp V-8 and a few drivetrain and suspension upgrades.
The next car to bear the ZR1 badge arrived in 1990. GM tapped Lotus to develop a four-cam, aluminum-block V-8 for the fourth-generation Corvette, with the goal of 400 hp and 400 lb-ft of torque. The 375-hp engine that resulted was indeed leaps and bounds ahead of the ordinary Corvette's iron-block V-8 - then producing a mere 245 hp - but it was also forty pounds heavier and far more expensive. Making matters worse, thanks to Chevy's insistence that the iron V-8's bore spacing and displacement be preserved, the bore-to-stroke ratio suffered. Ironically, Chevy's DOHC V-8 had mutated into a long-stroke compromise that wasn't optimized for high rpm.
Regardless, customers lined up to buy the 180-plus-mph, $58,995 ZR1, even though it commanded an absurd $27,000 premium over the base Vette. (Initial demand often pushed actual transaction prices beyond $100,000.) A six-speed transmission, wider rear tires, and new body panels came along for the ride. Yet demand dropped sharply after two years, and ZR1s stacked up on dealer lots. Just over 6900 cars had been sold when production ended in 1995. As for that fancy new V-8? It went the way of the dodo, shoved aside by a redesigned version of Chevy's pushrod small-block - one that was lighter, cheaper, and more compact. Given enough time, it would eventually far surpass its DOHC cousin in output, too: the current Z06's 505-hp, 7.0-liter pushrod V-8 is proof positive that complexity isn't always the best answer.
-Sam Smith