The original Corvette Grand Sports stalked racetracks in the 1960s, but the name went dormant until it was revived in 1996 for the final year of the C4-generation Corvette. With a 30-hp bump over stock and the wider wheels and tires of the mighty ZR-1—and the bulging fenders to match—that Grand Sport also sported a pair of fender hash stripes like those on the original race car, and it established the blueprint for production Grand Sport models going forward. For 2010, Chevrolet created another Grand Sport around the sixth-generation Corvette using the suspension and wider rolling stock from the Z06. And nowthe seventh-generation Corvette gains a Grand Sport option this summer for the 2017 model year.
Indeed, the 2017 Corvette Grand Sport adopts the strategy of borrowing suspension components and wider wheels and tires from a burlier variant and mixing them with the standard V-8 engine option. Just as the C6 Grand Sport got fat fenders, wider wheels and tires, and a sportier suspension tune designed to offer Corvette Z06–levels of handling in a more affordable package, so, too, does the C7 variant.
Wider is Better
Chevrolet bolts to the ’17 Grand Sport the current Z06’s cooling systems, wider rear fenders, and a look-alike grille. The 19-inch front and 20-inch rear wheels wear Z06-fitment 285/30 and 335/25 Michelin Pilot Super Sport rubber. The regular Corvette’s optional Magnetic Ride Control adjustable dampers come standard, as do specially tuned anti-roll bars and front and rear transverse composite leaf springs. The GS’s brakes are in-betweeners, with 14-inch front rotors and 13.4-inch rears being larger than the Corvette Stingray’s (even those on the optional Z51 performance package) but smaller than those on the Z06. Brembo six-piston calipers squeeze the front rotors, while four-piston units clamp the rears. Finally, the Stingray Z51’s electronically controlled rear differential is standard.
Power comes from the same LT1 6.2-liter V-8 engine used by Corvette Stingrays, albeit with those models’ optional dual-mode exhaust bolted up to every example. The sweet-sounding exhaust adds loudness and five horsepower to the Corvette’s V-8, bringing the sums to hellaciously loud and 460 horsepower. Chevrolet will offer both its seven-speed manual transmission and its eight-speed automatic, and the Grand Sport will be available in both coupe and convertible body styles. The fender hash stripes are optional—in your choice of six colors!—and so, too, are full-length body stripes.
Critically, the Grand Sport’s V-8 borrows its dry-sump lubrication system from the Z51-package Corvette Stingray. This lubrication setup is well equipped to handle engine oiling during high-g cornering—and the Grand Sport is certainly capable of some seriously high-g cornering, with Chevrolet claiming that this newest Vette can pull 1.05 g of lateral grip on the standard Michelin tires. The optional Z07 package is modeled after the Corvette Z06’s identically named bundle and brings that figure to a claimed 1.20 g. The Z07 kit includes Michelin Pilot Sport Cup 2 tires, carbon-ceramic brakes, and a passel of functional carbon-fiber pieces for aerodynamics. Of course, testing procedures and the size of the test skidpad can affect lateral-g readings, but we’ve coaxed 1.19 g out of a Z07-equipped Corvette Z06 on our 300-foot-diameter skidpad. Which is to say that Chevy’s estimates for the Grand Sport might not be hyperbole.
Grand Sporting, for Less
We enjoyed the C6 Corvette Grand Sport’s affordable-performance vibe throughout that model’s two-year production run, and we’re excited by the C7 version. The idea of throwing top-notch, track-worthy suspension components and tires at an otherwise base-level Corvette dovetails nicely with legendary Corvette maven Zora Arkus-Duntov’s efforts to slip racing-spec bits into ’60s-era Vettes to give consumers an edge at the track. While everyone remembers the five original Grand Sports as greatly underutilized racing cars that were cut down in their prime by General Motors’ arbitrary internal racing ban in 1963, Duntov sneakily offered consumers larger brake and fuel-tank options, as well as the famous L88 big-block engine option, in order to keep Corvettes winning at the racetrack. Unbeknownst to him at the time, the cherry-picking of high-performance components from GM’s parts bin laid the groundwork for the future Grand Sport line.
The supercharged, 650-hp Corvette Z06 is today’s halo Corvette, and while it remains a performance bargain at $80,395, its suspension, tires, and brakes are the critical components for track duty. (Okay, the extra 190 horsepower ain’t bad, either.) Chevrolet hasn’t yet said how much the Grand Sport will cost, but we expect that, like the previous-generation model, it will cost only a few thousand bucks more than a standard Corvette Stingray. For those jonesing for a track weapon on a budget, that makes the Grand Sport the ultimate toy. As bonuses, it can pull double duty as a daily driver—and leaves one with plenty of Z06 savings for replacement tires and brake pads.
source: caranddriver.com By ALEXANDER STOKLOSA