Change everything! Make it lighter, stronger and faster. Those were our guiding principles when I first started racing cars. Of course you ended up broke, with a vampire of a car that saw the light of day slightly less than John Barker's Capri, but just imagine if it had all worked properly, all at the same time? Welcome to the Chevrolet Corvette Z06. It looks like an ordinary Corvette, but it's faster. The works Corvette team has dominated its class in American endurance racing and at the 24-hour Le Mans race with the previous-model C5-R and, this year, with the new C6-R. The Z06 is pretty much an endurance racing C6-R with air con and a stereo - a 200mph race-car for the road. 'We've tested this car for 24 hours at Sebring and if you want to go 24-hour racing you don't need to change a damn thing,' snarled GM's Bob Lutz. 'You can take it from the showroom to the track. Porsche and Ferrari couldn't make that statement.' I just love cars like this. You really need to stick on a Kid Rock big-guitar track as you read the spec. In the case of the Z06, there really aren't many original parts left. Aluminium-alloy replaces steel; carbonfibre replaces aluminium-alloy. Up top there's a fixed magnesium-alloy roof and underneath there's a cast-magnesium engine cradle, pressure-formed aluminium-alloy perimeter chassis rails, twin double-barrel stainless-steel exhausts as big as Transatlantic pipelines, forged wishbones and dulled alloy panels. The floor is made of carbonfibre and balsa-wood! At 1419kg (including 45kg of additional radiators), the Z06 is 68kg lighter than a standard C6 Corvette. The engine is an all-aluminium Chevy small-block V8, a unit that's celebrating its 50th birthday this year. High-tech injection and electronic engine management are in place these days, but this single-cam-in-block engine is still an old-school basis for ultra performance. The 7-litre unit is hand-built in Wixom, Michigan, where they even deck-plate-hone the bores, a laborious process used to seal in the very last whistle of engine compression. Under the red cam covers there are titanium con-rods, inlet valves, pushrods and valve springs; the exhaust valves are sodium-filled; the cylinder heads are CNC ported; the steel crank and aluminium pistons are forged into shape, and the main bearings are dowelled to prevent them twisting under high loads. To prevent oil surge in corners, the engine has a dry sump, with a small sump pan under the engine from which oil is scavenged into a separate oil reservoir and then fed at high pressure to the engine bearings by a two-stage pump. The six-speed transmission and the uprated limited-slip differential have separate oil coolers, and the diff, half-shafts and clutch have been beefed-up to cope with the power and torque. There's even an exhaust valve, which opens a freer-flowing silencer box at 3500rpm and makes the Z06 sound like the race- track refugee that it is. The result is a very supercar-like 512bhp at 7000rpm (an unheard-of engine speed for a small-block V8) and a freight train-like torque figure of 469lb ft. Not that you get any indication of the Z06's super-hero status looking at it. There are discreet badges, a few aerodynamic add-ons, and the wheels and rear bodywork are wider than standard, but otherwise the silhouette is much the same as the standard C6's. The cabin is equally inscrutable, with a powerful air-conditioning system, comfortable leather seats and a radio - only the 200mph speedo gives the game away. Start it up and the engine idles quietly, although the gearbox fizzes and rattles alongside you. It's the transmission that alerts you to the car's capabilities; the gearlever feels heavy enough to be connected to the earth's engine room and the beefed-up diff drags the inside rear tyre all round the car park. Out on the freeway with a weather-eye open for the police, we slow to a first-gear crawl, switch the traction control off and floor it. The engine bellows like a Nascar and the wheels leave 20 yards of black rubber all over the road. So that's outright acceleration dealt with. Chevrolet claims a 0-60mph time of 3.9sec, which is entirely believable. It also wanted its supercar to be 'daily driveable' and to most extents it is. You need to develop a fine clutch and throttle control and the ride is harsh over the worst surfaces, but it's far more forgiving than anything tuned by Porsche. The hydraulically assisted steering is meatily weighted, with a slightly rubbery feedback. The brakes are huge, with six-piston racing callipers on the front, clamping 335mm crossed-drilled rotors. These are as effective at low speeds as they are when you're racing along and don't clank and squeal like similar anchors on rival supercars. The Z06 is long-geared, doing about 50mph at 1000rpm in sixth gear, which perhaps explains why it doesn't attract any gas-guzzling tax in the US. Top Gear television presenters are apt to scoff at the Corvette's transverse leaf springs, but there's nothing wrong with them if all they do is supply the springing medium and not axle location as they do here. The Z06 can be turned-in on the brakes, but prefers a slight pause between braking and turning. Once in the corner the springs allow a small amount of roll and the wheels continue to ride bumps well. Even so, the chassis isn't as communicative as some and you can find the rear tyres sliding wide with little warning. It's a good-natured car, though, and in cases of severe driver abuse there's also a brilliantly progressive traction-control system. Not that this is a simple point-and-squirt machine. This hepped-up Corvette might not be the last word in sophistication, but it can be hustled along tight roads and thrown around with enormous confidence. Like any super-powerful car, however, you need to learn what it can do before exploiting its potential. The Z06 is also surprisingly practical, with a good ride, luggage space and a comfortable cabin. A 'daily driver', as Chevrolet has it. More like a superhero really, especially for under 60 grand. Shame they're all left-hand drive. GM says that just 250 Z06 models will come to Europe next year, although it will be trying to secure another 50 of the 7200 annual US Z06 production. I don't think it'll have much trouble shifting them.
|Engine||V8, 7008cc, 16v|
|Max power||512bhp @ 6600rpm|
|Max torque||469lb ft @ 4800rpm|
|Top speed||198mph (claimed)|
|On sale||January 2006|