Yahoo Autos The 2001 Corvette Z06 Balanced the American Sports Car War
When Ford threw down the gauntlet with its 385-bhp Mustang Cobra that promised Corvette-like performance, Chevrolet wasted little time in answering the challenge.
For 2001, Chevy will take the wraps off the long-awaited 385-bhp Corvette Z06, a car that promises better performance in both acceleration and handling than both the Cobra R and the legendary ZR-1 at a price that won't break the bank.
Rooting around in nearly 50 years of Corvette history, Chevy engineers came across the original Z06 package conceived by chief engineer Zora Arkus-Duntov for the 1963 Sting Ray. Duntov's vision was for a race-ready car you could buy off the showroom floor, not unlike today's Cobra R.
This story originally appeared in the August 2000 issue of Road & Track.
In addition to the higher-performing fuel-injected small-block V-8, a 36.5-gal. tank for endurance racing, 4-speed manual, beefed up brake and Posi-traction, the 1960s' Z06 package came without carpeting and sound-deadening material as a way to cut weight and improve performance. The Z06 package back then wasn't cheap— it cost $2480, nearly 60 percent beyond the Corvette's $4237 base price. Again, echoes of the Cobra R.
But for its modern-day Z06, however, Chevy departed from the script by using its hardtop and keeping all the creature comforts people have come to expect from high-performance cars, including air conditioning, a sound system and a modicum of sound-deadening material.
The heart of the Z06 is the new, more powerful LS6 5.7-liter V-8 (the LS6 designation came from Duntov’s 1971 425-bhp optional big block) mated to a 6-speed manual with gear ratios specific to the package.
The base hardtop, as we knew it, is gone— all of these fixed-head coupes will be Z06 models and are expected to be priced roughly the same as the Corvette convertible, somewhere around $45,000. The Z06 is pitched specifically at hardcore enthusiasts, who may either race or slalom on weekends.
Styling changes to the Z06 are subtle, although the car is easily recognized by the mesh-covered cooling inlets for the rear brakes, positioned just aft of the doors. The same mesh material is used on the front air intakes. Other cues include unique open 5-spoke wheels that expose the red brake calipers, red valve covers, prominent Z06 badging on the front fenders, Z06 emblems embroidered on the headrests, and red seat and door inserts (though black leather may be substituted).
The biggest change, of course, is the LS6 engine. The aluminum block and heads are unique to the Z06 package, though some improvements have been made t0 the induction system (the plenum volume has been increased and the runners smoothed for better flow) are shared with the LS1.
Starting with the block, special openings replace machined holes in the cylinder bulkheads to reduce crankcase backpressure on the downstroke, which lessens parasitic power loss. The pistons are new, cast from high-strength M142 aluminum alloy. The tops have a new profile that, along with smaller pent-roof combustion chambers in the heads, raises the compression ratio from 10.1:1 to 10.5:1.
The LS6 also benefits from a high-profile cam. Lift is increased from 12.7mm to 13.3. This high-lift/high-duration profile required stronger valve springs. Though using the same wire as the springs on the LS1, the LS6’s springs are wound tighter for a higher rate. These improvements have allowed the redline to be raised 500 revs to 6500 rpm.
To handle the extra torque (now 385 lb.-ft. at 4800 rpm, an increase of 35 lb.-ft.), a new clutch with greater clamping power has been developed. Clutch take-up is smooth and progressive with the sort of ease that belies the beefier componentry. The Z06 also has its own gearbox, the M12, with close-ratio, shorter lower gears to improve acceleration. For instance, 1st is 2.97:1, compared with the 2.66:1 ratio used on the LSI’s MM6 gearbox. The shifter itself provides quick, positive gear changes as the result of a revised linkage that eliminates the plastic bushings used to smooth the action on the stock Corvette. What the Z06 lacks in fluid movement it more than makes up in a tighter, more mechanical feel.
Weight savings did not come at the expense of air conditioning, the sound system or even high-tech gizmos like traction control or stability control. Instead, weight reduction is the result of high-tech tinkering. Glass is thinner. There is less insulation, but the carpets and leather seating surfaces remain. The exhaust system, including muffler, is titanium, the first such use of the lightweight material in this application. Overall, the Z06’s curb weight of 3115 lb. is nearly 115 lb. lighter than the coupe and just 5 lb. lighter than last year’s hardtop.
The Z06 is electrifying to drive. From the moment you crack open the throttle, you can tell this is something special. Acceleration builds as quickly as the free-revving engine hits the higher redline. In track testing we saw 4.6 seconds from 0 to 60 mph and felt we were leaving more than a few tenths on the table because of some axle tramp when leaving the blocks. The quarter-mile came up in 13.0 sec. at 110.5 mph. The Z06 clocked in 0.2 sec. faster than the Cobra R in both 0-60 and quarter-mile contests.
But the beauty of the Z06 is not confined to the thrills of straight-line acceleration, as gratifying as these improvements are. The real eye-opener is the way this car handles, thanks in large part to Goodyear’s efforts in building the FI Supercar tire specifically for the Z06. Using an asymmetrical design, the new F 1 Supercars leave a huge footprint.
The front 17-in. alloy wheels wear P265/40ZR-17 tires, while the rear 18-in. wheels have P295/35ZR-18 rubber—a full inch wider than the stock Corvette’s tires. These have better grip partly because they do not incorporate run-flat capabilities, and while there is no spare, the Z06 is equipped with an emergency tire-inflator kit for limp-home capability. In addition to the new wheel and tire package, the Z06 also has a half-degree more negative camber (now 0.75 degrees) than the stock Corvette, which helps to maintain a more optimal contact patch while cornering.
These tires and revised settings enable the car to pull 1.00g on the skidpad and helped it blast through our 700-ft. slalom course at 67.1 mph, almost 3 mph faster than the race-ready Cobra R.
During track testing at Mid-Ohio, we were instructed to start out in the current Corvette, then drive the 2001 LSI and finish off in the Z06. It’s easy to see why Chevy insisted on this progression. Once in the Z06, I didn’t want to go back to the other Vettes.
The FE4 suspension, which features a larger 30-mm front anti-roll bar along with a higher-rate rear transverse leaf spring, provides a taut yet stable ride. It feels firmer than the optional Z51 sport suspension and yet has enough compliance to pass muster as a daily driver. The combination of the suspension and unique Goodyear tires imbues the Corvette with prodigious grip. The car corners flat, and with traction control off, the ease of kicking out the tail is matched by the predictability of the response. It is almost impossible to find a situation where you feel as if you have lost all grip and the tail is about to snap away. And the LS6 ensures that you will have all the power you need to control this car with the accelerator.
Although the car is equipped with the same settings on the Magnasteer power-assisted rack-and-pinion steering, the larger tires with a bigger bite give the Z06 crisper turn-in. On a small slalom course set up in the parking lot at Mid-Ohio, the Z06 was consistently 2 sec. faster than a 2000 Corvette equipped with the Z51 suspension.
While the Z06 is a bit noisier inside than a stock Corvette—primarily because of the thinner glass, less insulation and throatier exhaust—it still has the feel of a finely honed piece. Body integrity is good, thanks to the fixed roof, and the stiffness of the suspension lends an air of solidity. The sure throws of the shifter and the instant response o f the engine give this Corvette the sense of immediacy and purpose of a pure sporting machine.
The Z06 again changes the balance in the American sports-car wars. Though it still lags behind the Dodge Viper in raw power, the Corvette Z06 compensates with superior handling and the availability of stability and traction control. It is also the most refined when compared with either the Viper GTS or the Cobra R. It handily beats the Dodge and Ford on price, and trumps both on availability. Fully 20 percent of Corvette production (which runs between 25,000 and 30,000 per year) will be Z06s. With 5000-plus on the market, you’re more likely to see the Z06 on the track rather than in the clutches of some collector. The Empire has struck back in big numbers. And that’s a good thing.
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