Space Shuttle Aficionado
Drives: 1959 Edsel Ranger
Join Date: Jun 2010
First Test: 2014 Chevrolet Corvette Stingray Z51
Chevrolet Corvettes have always been adept track stars -- a ZR1 set the pace at our 2009 Best Driver's Car competition, and a Z06/Z07 laid down the quickest lap at that event in 2011. Maintaining a close relationship with a successful racing team assures that. But it's telling that each of those lap-time champions finished sixth in its running, thanks to comments like these: "My knuckles were a lot whiter at the wheel of the ZR1 than they were in the Audi" (racing pro Randy Pobst); "The ZR1 does not elicit relaxed smiles or slow sighs of ecstasy, only pants and palpitations" (editor-in-chief Edward Loh); and -- referencing the Z06/Z07's semi-slick Pilot Sport Cup tires -- "The ultra-gumballs help highlight just how inferior the seats are" (associate road test editor Carlos Lago).
Well, the time has come to see if indeed the 2014 C7 Corvette has put all that right -- to find out if the beast has been tamed, and if so, whether said taming has neutered the lovable aspects of the beastliest C6s. In short, can it still lay down hero numbers -- without soiling the hero's pants?
Our first answers lie 3.5 miles away on the "black lake" at GM's Milford Proving Ground, but before chief engineer Tadge Juechter will turn us loose to start measuring numbers, he's got a PowerPoint presentation for us.
While three eager editors fidget, knees bouncing, the slides reveal a few new factoids such as the now SAE-certified engine output ratings: 455 hp at 5900 rpm and 460 lb-ft at 4700 rpm for the base engine; 460 hp/465 lb-ft (at the same revs) with the $1195 Dual-Mode Performance Exhaust. This system (RPO NPP) more or less bypasses the rear mufflers with a pair of exhaust butterflies. Juechter also discloses that, when operating as a 3.1-liter V-4, the LT1 produces 126 hp and 221 lb-ft at 3000 rpmthat's 10 times the power needed to maintain 50 mph, and it's sufficient to sustain 90 mph on flat ground. (I checked.)
Other bragworthy numbers include the preliminary EPA estimates of 17 city mpg/29 highway for the seven-speed manual. (Figures for the automatic are not yet available.) That's up from 16/26 for the C6 and ranks the Stingray as the least thirsty 450-plus-hp car on the market. Pretty impressive, given that, even with the new aluminum frame, the weight of our test car actually went up 69 pounds relative to the last Corvette Grand Sport we tested.
Let's fast-forward to the black lake. I warm the car up with numerous laps of the figure-eight course, trying different modes. Everything off proved too hard to control, but Track mode with the Dry program seemed to allow the ideal slip angle. The new Michelin Pilot Super Sport ZP tires are supposedly quite a bit stickier, but GM's asphalt feels a smidge smoother than the aggregate at California Speedway, where we tested our last C6 Grand Sport. Hence lateral g increases "only" to 1.11 g from 1.09; our lap time of 23.9 seconds at 0.82 g was 0.2 second off the Grand Sport's; and our 60-0-mph braking distance stretched to 104 feet from 101.
With all gauges and tires showing "warm," I line up for eight acceleration runs: four with launch control (traction off, clutch in, floor the throttle, let revs stabilize, release clutch, and let computer modulate) and four without. The computer launches at around 4000 rpm, and each run registers within a tenth of a second -- great for bracket racing, but I know she'll bite harder with fewer revs. Sure enough, with about 2800 rpm, careful modulation, and earlier hook-up, I'm better than a tenth quicker, with my best two-way average working out to 3.9 seconds to 60 mph and 12.2 at 117.3 mph in the quarter. That pretty evenly splits the difference between the Grand Sport and 427 C6 models (12.5 at 115.0 and 11.9 at 121.5). The seven-speed shifter proves easy to shift quickly, with only one missed shift in eight runs, though as a mechanism it's nowhere near as delightful to snick around as a 911's.
With hard numbers in hand, I strap in for a demo of the continuously variable-locking differential. Maintaining 60 mph, I jerk the wheel 30 degrees right. With the diff open, the car slews into a dramatic tank-slapper; when fully locked, the car tracks through perfectly. For any given combination of throttle, brake, steering, tire temperature, etc., this new eDiff can serve up precisely the percentage of lock required to produce the desired slip angle, as indicated by the drive mode and Performance Traction Management program selected.
To showcase the bandwidth of these selections, I take a dozen laps of an autocross course in a new Z51 outfitted with the $1795 magnetic ride-control package. From the Drive Select knob's Track mode, I press the traction control button twice, opening the PTM menu, and progress up through the Dry, Sport 1 & 2, and Race sub-selections. (There's also a Wet mode.) Each twist of the dial makes it easier to point the nose with the throttle, and in some of these tight turns, this helps a lot. It strikes me that the electronics are serving as a quasi-stand-in for a pit crew swapping out anti-roll bars and damper settings and "wedging" the suspension to tailor the car for the conditions of a particular track. You can also program new combinations, such as Track mode's heavier steering effort in Touring mode. Cool.
Our last stop is the big Milford Race Course, aka Lutzring. Here, the turns are much bigger and faster, and all hills and dips are designed to upset the chassis. Once again, I start off in Track mode, toggling through the PTM programs and taking full advantage of the rev-match system. (It can be toggled on and off via either steering wheel paddle, and the gear indicator on the dash glows orange when it's engaged.) I end up preferring one of the "middle" PTM settings for the greater control it provides on the rise coming off turn eight, but with each lap I marvel at the way the magnetic shocks cushion the rough transition onto the carousel apron without ever bottoming out. These shocks make the car ride like it's suddenly wearing 55-series tires.
After my final lap with all nannies switched off, I dial back to Touring mode (forgetting to reengage StabiliTrak) and nearly loop it in the first turn. The combination of much lighter steering (and hence too much input) with reduced body-motion control and no nannies reveals how much of my heroic driving in the few laps before had relied on electronics. I got the same sensation the first time I switched everything off in a Ferrari 599 -- three cheers for trickle-down technology. In Sport mode, the car feels a little nervous when driven hard on the track, with too-light steering and insufficient body control.
I later ride shotgun for a few laps with Corvette team racer and three-time ALMS champ Ron Fellows, who turns everything off and generates face-distorting gs in every direction. These ultra-hot laps reveal the new base GT buckets to offer considerably better support than the C6 chairs, but (narrow-of-beam) drivers serious about tracking their C7s should hold out for the $1995 Recaro thrones, which will arrive about the time the convertible arrives in late 2013. Just don't expect them to deliver New York-to-Miami comfort.
So far the loaded Z51 seven-speed test cars impress me with their greatly broadened performance envelope, but what about the base car? There just so happens to be such a beast on hand for drives around the perimeter of the proving ground. First impressions: The vinyl-wrapped interior virtually matches the look, but not the smell, of the leather-wrapped one that comes with the $8005 3LT package, and the base woven nylon A-pillar/roof trim is shinier and less posh than the sueded microfiber trim, but maybe not $995 worth. Taking no chances, the team changed nearly every single thing you see and touch in the interior, from the frameless, compact inside rearview mirror to the loop pile carpet, and there's an unprecedented ability to personalize it with options including a carbon-fiber dash panel, sill plates, custom luggage, and even a "color-combination override" ($590, sold orders only)
All Corvettes get the big touch screen and a drive-mode selector, but without the magnetic shocks or eDiff, the latter doesn't do as much. The base nine-speaker Bose stereo doesn't quell the V-4-mode thrum as thoroughly as does the 12-speaker one with the 9.1-liter bass box. Ride quality is exceptional, and even with the roof panel out, the car feels as rigid as a Mercedes SL -- no twist or shake, no motion in the door-to-dash gap, nothing.
I also take a public-road spin in a Z51 automatic, and note that, even in the magnetic shocks' softest setting (with damping rates lower than those of the base suspension), the bigger wheels and stiffer anti-roll bars produce a slightly more jarring ride. While the automatic gets well-positioned shift paddles, the transmission also utilizes performance-algorithm shift logic that holds lower gears in sharp cornering, downshifts if you blip the throttle while slowing down, grabs lower gears when braking into a turn, etc.
Gadget lovers will revel in the dizzying array of instrument panel configurations. Three basic themes coordinate with the laid-back Touring, higher-adrenaline Sport, or full red-mist Track settings, presenting info tailored to the driving style. (Analog speedometer, fuel, and coolant-temperature gauges are always active.) There's room on each screen for a wealth of other info such as 0-60 or lap timing, a g-load diagram, tire temperatures -- even total engine hours and revolutions! (Our test car's 781 miles had racked up 1.76 million revs in 21.9 hours.) The Chevy MyLink system is app-ready, and its high-resolution touch screen is twice as bright as Apple's latest Retina display to withstand direct sunlight with the top off. Lower the screen, and you can store valuables and connect a USB stick or phone in the "safe" behind it. You can also control most infotainment functions using relatively natural voice controls. Further comment on its overall user-friendliness must wait for a longer drive.
So what answers did I come away with? Yes, the ability of StabiliTrak to twiddle electronic differential, magnetic damping, and myriad other settings while simultaneously modeling the tire temperatures and more seems almost wizard-like in the way it squeezes the utmost performance and handling out of the C7 Z51's more rigid chassis and stickier Super Sport tires. The magical result is quite simply the easiest Corvette yet to thrash hard. And, yes, it does so without emasculating the car or making it feel anodyne, while preserving its essential Corvetteness. The view out over its impressively low, long hood is similar to that of every Corvette since the last Stingray. The burbling fourth-order engine and exhaust notes are every bit as intoxicating as the first Sting Rays'. And its ability to lope along in V-4 mode displaying instantaneous economy in the 40-plus mpg range gives hope that the venerable small-block may well survive to power C8 and C9 'Vettes. Based on one memorable day in Milford, I predict Pobst's knuckles will be pink and Loh may even sigh in ecstasy while flogging the C7.