Chevrolet Grand Sport C6 Corvette 2010 to 2013. Shares parts with Z06 Corvette models. LS3 Engine, Dry Sump.
More of a Good Thing
Replacing the previous (and highly recommended) Z51 package—it added larger wheels and tires, a stiffer suspension, bigger brakes, and shorter gearing to the base Corvette coupe or convertible—the Grand Sport shares a name with limited-edition models from 1963 and 1996 but is a new model line and not a low-volume special. In fact, Chevy is predicting that nearly 50 percent of Corvette sales going forward will be Grand Sports, citing claims that its customers were clamoring for more Z06-ness but without that 505-hp beast’s coupe-only and manual-transmission-only limitations. That’s why, as with the Z51 package, the Grand Sport, which starts at $55,720, or $5840 more than a base Corvette, is offered as a convertible or targa-topped coupe and with a manual or automatic. An available Heritage package brings the iconic Grand Sport front-fender hashes as well as two-tone seats.
As for the mechanicals, the Grand Sport keeps the base car’s 430-hp LS3 V-8 (436 hp with the optional exhaust) and steel frame but gets lots of Z06 bits, including its much larger tires (275/35-18s in front and 325/30-19s in back), wider track, cross-drilled brake rotors (14.0-inch fronts and 13.4-inch rears), and visual add-ons (front air inlet, bulging fenders, and rear brake-cooling ducts) that go more than skin deep, as they reduce aerodynamic lift by half. And although drag is increased, there’s no penalty to fuel economy, which remains an impressive 16 city/26 highway mpg for the coupe, 15/25 for the convertible. The only thing the Corvette really needs now is a remedy for its cheap-looking interior plastics; the available beyond-fake-carbon-fiber-wannabe surround for the center stack is particularly egregious. The cabin needs a breakthrough on par with the ones seen in the second-gen Cadillac CTS or the 2010 Buick LaCrosse.
Ready for Launch
The best Grand Sport value is the manual-transmission coupe, which gets a differential cooler and the dry-sump oiling system that’s shared with the Z06 and ZR1 and nearly doubles capacity, to 10.5 quarts. An additional benefit is that the dual oil pump and longer crankshaft used in conjunction with the dry-sump setup mean that those particular LS3 engines are hand-built alongside the LS7 and LS9 from the Z06 and ZR1.
Another welcome addition on all 2010 manual-transmission Vettes (including Z06s and ZR1s) is launch control. Simply put the car into “competition mode” by clicking the stability/traction-control button twice, and it’s armed. Push in the clutch and mat the throttle, and the revs rise to roughly 4500 rpm—the precise engine speed depends on the ambient temperature, among other things. Dump the clutch and the system ascertains the available grip by the viciousness of the initial wheelspin and then precisely modulates the torque sent to the wheels by adjusting the fuel and spark delivery 100 times per second while keeping the throttle wide open. Although the excess wheelspin used to calibrate the launch means the system’s times aren’t quite as good as those possible by the best drivers, it’s within 0.1 or so second and is extremely consistent.
The Right Balance
Weight is up about 40 pounds to just over 3300, roughly 100 more pounds than the Z06, and straight-line performance isn’t predicted to improve over the Z51’s 4.0-second 0-to-60-mph time, but we plan on a skidpad figure of at least 1.00 g when we get our hands on a Grand Sport for instrumented testing. Unfortunately, the lack of lateral support from the same flimsy seats that we’ve long complained about is still a big issue. The shift effort in manual cars still tends toward manly, but the broad torque is addicting, as is the roar that turns into a ripping snarl when the flaps open on the optional exhaust. This is truly a car that can easily withstand serious track time as is, which is impressive considering that the base Corvette’s forgiving ride isn’t sacrificed. Whereas pushing a Z06 always seems dangerous, the Grand Sport feels far less suicidal; the burlier Vette’s larger tires and instantly responding, slop-free brakes seem to suit this new model perfectly. But don’t think we’ve gone soft; there’s still plenty of power to break the rear tires loose and ruin your day. Aside from the $109,130 ZR1, this is our new favorite Corvette on the track.