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This is America’s track star.
From the May 2014 Issue of Car and Driver
Plucked from GM’s last track-day special, the 2013 Corvette Z06, the Z/28’s port-injected LS7 V-8 is fortified with new pistons and titanium connecting rods whose bearing inserts are now spray-coated for improved durability. There’s also a cold-air intake, revised exhaust headers, and a repackaged dry-sump oiling system, but there’s more hardware that’s carry-over than new under the hood. At 505 horsepower and 481 pound-feet of torque, the Z/28’s LS7 makes just six pound-feet more than when this engine made its debut eight years ago.
Save the Manuals!
Just as it did back then, the LS7 oozes power whether the Z/28 is standing still or at speed. The car quakes under a lopey idle as heat radiates from the carbon-fiber extractor and blurs the view through the windshield. Racing toward a 7000-rpm redline, the Z/28 smears Barber’s manicured landscaping as if it’s a still-wet watercolor while the exhaust’s raucous bawl rattles the cabin. Zero to 60 mph passes in 4.4 seconds and the quarter-mile clears in 12.7, by which time you’re doing 116 mph. True, the Z/28 isn’t as quick as the ZL1 in a straight line, but that’s not the point.
The six-speed manual transmission shared with the Camaro SS 1LE is geared for road-course duty, with closer ratios passed through a shorter 3.91:1 final drive. Shifts are heavy and stiff, and the pedals are spaced a toe’s-width too far apart for easy heel-toe action. The substantial displacement of the naturally aspirated V-8 compensates with a low end that’s nearly as forceful as its top end is intense. We work over Barber using third and fourth gears and every rev between 3000 and 7000 rpm.
The Pirelli P Zero Trofeo Rs are essentially street-legal racing tires so tacky that, during development testing, they occasionally stuck to the pavement better than to the wheels they were mounted on. To keep the Pirellis from slipping around the rim, the wheels on production Z/28s are media-blasted to increase friction at the mating surface, a common practice in racing.
The massive front tires are the same size as the rears, a remedy first used on the 1LE to address the Camaro SS’s penchant for understeer. Here, though, the rubber is sized up to 305/30 and mounted on smaller, lighter, 19-inch forged aluminum wheels. When warm, the tires stick to the pavement like four wads of melted Wrigley’s. In Barber’s long, mid-speed corners we saw as much as 1.06 g’s of lateral stick despite a damp track and temperatures struggling to top 40 degrees. The Z/28 is neutral and responsive at the limits, and the Torsen-type limited-slip differential prudently doles out power on corner exit. The flat-bottomed steering wheel has the same heft and on-center sharpness as the Camaro ZL1’s. Unfortunately, it lacks the stimulating feedback of the best sports cars.
The cross-drilled carbon-ceramic discs are clamped by six-piston front and four-piston rear calipers that bite just as hard after 50 minutes of lapping as they do on the first laps. From 70 mph, they haul the Z/28 to a stop in 155 feet.
There are, of course, stiffer springs and bushings, and the downsized wheels allowed engineers to drop the center of gravity by 1.3 inches and use smaller and lighter anti-roll bars. The cornerstones of the suspension are four spool-valve dampers, a technology used by Red Bull Racing as it claimed four Formula 1 championships between 2010 and 2013. Until now, the closest these shocks have come to a production car is Aston Martin’s $1.8 million One-77.
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