ZR1: For on and off the track

Wednesday, August 20, 2008
Henry Payne, Detroit Auto News

Want some ZR1 advice? Don't buy it unless you plan to race it.

Driving the brand new, $103,000 Corvette ZR1 on the street is not much different than driving the $47,000-base 2009 Corvette C6 coupe -- already one of the world's finest two-seater sports cars.

Both models offer attractive interiors, comfort, and unobtrusive sound from their 6.2-liter engines. And the standard C6's 420 horsepower and 420-pound-feet-of torque provides plenty of get-up-and-go to stomp on any 911 or M3 lurking at a stop light. So why pay the $50,000 premium on the ZR1?

Because, when unleashed on the race track, the ZR1 proves to be a serious competition car wrapped in production vehicle's clothing.

As a veteran race driver of 25 years, I have competed in a variety of sports cars, including purpose-built racing prototypes like the 1969 Porsche 908 (the first Porsche to win the world manufacturer's championship) and the 1977 Toj 205C (one of the first winged sports racers and perhaps the fastest 2-liter car of its era).

The ZR1 is in the same league with these race-spec automobiles. And unlike similar super cars like the Ferrari 430 Scuderia or the Porsche GT, it achieves this performance for a price well south of the usual $250,000 super-car sticker.

An afternoon of driving the ZR1 on General Motors Corp.'s challenging test track in Milford is proof that the General's "ultimate Corvette" deserves to be mentioned in the same breath -- not with other production GTs -- but with sports racers. With 14 turns snaking over 3 miles, GM's Milford facility is reminiscent of great American tracks like Mid-Ohio or Watkins Glen, and is a firm test for Vette and driver.

Weight is the first fundamental that separates race cars from the average street GT. Even as the Porsche 908 has roughly the same 350 horsepower as, say, a 2008 BMW M3 Coupe, it weighs only 1,350 pounds compared to the M3's 3,450. The resulting 4:1 weight-to-power ratio makes the 908 more nimble and powerful coming off corners compared to the M3's 10:1 ratio (common to Audis, Porsches and other fast street coupes).

But not to the ZR1.

While the car's supercharged, 6.2-liter engine produces a mind-boggling 638 horsepower and 600-pound-feet of torque, it does so in a 3,324-pound package, giving it a 5:1 weight-to-power ratio within striking distance of the finest racing prototypes. Moreover, though the Vette is front-engined, its transmission is in the rear, giving the car a 50-50 weight balance similar to mid-engine sports racers.

In other words, the ZR1 chassis is bred for racing, and its 12-inch rear and 10-inch front tires (about the same as the 908, coincidentally) provide extra stick to slide through corners while dialing in the power. Only the ZR1's slight body roll -- the inevitable result of its streetable (if still stiff) springs -- reminds you that the car is not fully race prepared.

But the real revelation of the ZR1 is its brakes.

Like modern LeMans race cars, the ZR1 is outfitted with massive, light-weight carbon-ceramic discs that quickly dispense heat to prevent brake fade and pad wear. Unlike modern racers, however, the ZR1 benefits from a state-of-the-art ABS (anti-lock) brake system.

The result are brakes that far exceed those on the 908 or Toj (much less any street hot rod. Consider: The vaunted M3 accelerates from 0 -100 in 11.3 seconds. The ZR1 goes from 1-100 -- AND BACK TO 0 in less than 11 seconds!).

Driving toward Turn 6 at the Milford at 100 mph, the driver can wait until the last moment, stomp with all his might on the brakes and confidently turn into the corner without fear of lockup thanks to the ABS computer monitoring all four corners. Try this in a sports racer -- even one weighing 1,300 pounds, and you will lock up the fronts and plow straight off the track.

This Superman braking allows -- demands -- driving beyond the limit. The key to driving the Porsche 956 "ground effects" prototype of the 1980s, world champion Brian Redman once said, was keeping your foot in a corner beyond what your brain told you was safe -- because at that point the aerodynamics of the 956 really started to work.

Similarly, the ZR1's brake system encourages overdriving into corners -- because the brakes will not only save you but allow you to comfortably rotate the car into the apex. While I only tested the outer limits of these capabilities in my one-day familiarization with the ZR1, a couple laps spent in the passenger seat with GM's test driver, Tony, was a remarkable demonstration of how far the ZR1's brakes can push the envelope.

With its power and brake capabilities, the ZR1 blurs the line between production car and racer. So buy it. Then start reserving weekends to travel Grattan Raceway, Mid-Ohio Sports Car Course, Watkins Glen International . . . .

Henry Payne is a cartoonist and writer for The Detroit News. He can be reached at hpayne@detnews.com.