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Chevrolet finally builds a Z06 convertible. Almost.
Whatever you do, don’t call the Chevrolet Corvette 427 convertible a Z06 convertible. Never mind that beneath its carbon-fiber Z06 hood and between what look like the Z06’s carbon-fiber fenders sits the Z06’s dry-sump 7.0-liter V-8 spinning the Z06’s six-speed manual—the only transmission available, just as in the Z06—and directing power to the Z06’s rear axle, which is equipped with the Z06’s available magnetorheological shock absorbers. Chevy refuses to call the 427 droptop a Z06 for a much simpler reason: Supporting its carbon-fiber and balsa-wood sandwich floor panels—same as the Z06’s—is the hydroformed steel frame from the base Corvette rather than the aluminum structural core of the Z06 and ZR1. Also, engineers insist that the Z06 was designed from the ground up to be a coupe and that it wouldn’t take kindly to having its magnesium-reinforced roof panel simply removed.
But if you consider the 427 to be in every other way a Z06, you’re correct. With the exception of the frame and the roof, most of the stuff that makes a Z06 is here.
Not surprisingly, all that Z06 equipment makes the 427 drive a lot like the Z06. First of all, it has the same steering. Calling it “immediate” doesn’t do it justice. It’s almost twitchy and demands absolute attention—as do the car’s tremendous limits. We recorded 1.03 g on the skidpad, enough lateral acceleration to make you wish you did more core-strength conditioning. With the Z06’s brakes also aboard, the 427 stops as if it were grabbing an arresting cable. The 427 screeched from 70 mph to a standstill in 144 feet, two shorter than the last Z06 we tested.
Much of the 427 convertible’s equipment is available on the mid-level Grand Sport roadster, but the one thing that defines the Z06—its 428-cubic-inch LS7 V-8—is the 427’s main draw. (Chevy fudges the displacement as an homage to the old big-block engine—feel free to call it, more accurately, the 428.) It’s a nearly faultless mill, brutal and ferocious, with a yawp that will make anyone pine for a big-inch V-8 of his own. The LS7’s 505 horsepower and 470 pound-feet of torque seem to manifest at every point in the rev range, and the LS7 slings the 427 to 60 mph in 3.9 seconds and through the quarter in 12.2. A quarter-mile that quick places any car in elite company, but it puts the 427 on an even shorter list of convertibles. As does its 182-mph top speed.
Chevy quotes a base price of $76,900—that’s $325 more than a Z06. As typical convertible premiums go, Chevy might as well be paying customers to take the 427 instead of the Z06.
All Corvette convertibles have their faults—seats that, although improved for 2012, still aren’t up to the performance of the car; a structure that isn’t quite as rigid as the coupe’s; a power top you have to manually unlatch; scary breakaway behavior—but one thing you’ll never hear us complain about is the LS7. It’s a great engine, and we’re still surprised it has taken Chevrolet this long to install it in the convertible body. The next-generation C7 Corvette is just around the corner; hopefully, droptop customers won’t have to wait as long to get a monster-engine version of an open C7.
Specifications
VEHICLE TYPE: front-engine, rear-wheel-drive, 2-passenger, 2-door roadster
PRICE AS TESTED: $91,135 (base price: $76,900)
ENGINE TYPE: pushrod 16-valve V-8, aluminum block and heads, port fuel injection
Displacement: 428 cu in, 7008 cc
Power: 505 hp @ 6300 rpm
Torque: 470 lb-ft @ 4800 rpm
TRANSMISSION: 6-speed manual
DIMENSIONS:
Wheelbase: 105.7 in
Length: 175.6 in
Width: 75.9 in Height: 48.7 in
Curb weight: 3421 lb
C/D TEST RESULTS:
Zero to 60 mph: 3.9 sec
Zero to 100 mph: 8.7 sec
Zero to 150 mph: 20.4 sec
Rolling start, 560 mph: 4.6 sec
¼-mile: 12.2 sec @ 121 mph
Top speed (drag limited): 182 mph
Braking, 700 mph: 144 ft
Roadholding, 300-ft-dia skidpad: 1.03 g
FUEL ECONOMY:
EPA city/highway : 15/24 mpg
C/D observed: 14 mpg
TEST NOTES: Like the Z06, the 427 can hit 60 in first gearbut just barely. Shift early and 0-to-60 suffers, but the quarter-mile time will be nearly the same. The best launches are at about 2700 rpm, resulting in optimal wheelspin.
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