Sweet Spot

Though all three of the 2014 Corvette Stingray convertibles we sampled were great, one had a combination of optional equipment that made it that much better.

Photo: Sweet Spot 1
January 23, 2014

The arrival of the Stingray convertible is reason to rejoice for open-air devotees, even though the C7 coupe, with its removable roof, already offers much of the drop-top experience. But, as Corvette Chief Engineer Tadge Juechter puts it, “There’s nothing like taking away [the coupe’s roll-over bar] and having nothing between you and the sky.”

The good news for convertible buyers gets better, too, because there’s supposed to be no performance penalty to pay compared to the coupe. That’s because, as with the C5 and C6, the C7 was designed from the start to work as either a coupe or a convertible without requiring structural differences. “The suspension tuning is exactly the same, the parts numbers are the same,” emphasizes Juechter. “In terms of chassis rigidity, the convertible is as stiff as the coupe with its roof out.” The 30-pound heavier convertible is also just as quick as the coupe. Chevy claims both models do the 0-60 mph sprint in just 3.8 seconds (when outfitted with the optional Z51 Performance Package).

In short, Chevrolet says that the C7 convertible offers the best of both worlds: open-air enjoyment and the performance we’ve lauded in our earlier tests of the coupe. Does the drop-top Stingray deliver on this promise? There was only one way to find out, which is why, in early December, we found ourselves in Palm Springs, with two days to drive three very different C7s.

First, though, let’s back up to the convertible’s genesis. Chevy introduced the new Stingray in coupe form back in January 2013. Compared to its C6 predecessor, the C7 boasts numerous technological and performance advances. These include, but are not limited to: a standard aluminum chassis (formerly seen only on the high-performance Z06 and ZR1 models); a carbon-fiber hood and roof panel (the material was likewise previously reserved for the Z06 and ZR1); an all-new, 455-hp, 6.2-liter LT1 V8 engine, which features direct fuel injection, continuously variable valve timing and cylinder deactivation; a seven-speed manual transmission; the Driver Mode Selector, a dial on the center console used to put the car in (bad) Weather, Eco, Tour, Sport or Track mode; bigger brakes; Michelin Super Sport run-flat tires; and, as part of the Z51 package, an electronic limited-slip differential and even larger Brembo brakes. Thanks to all these changes, the base C7 has better roadholding and straight-line acceleration than the C6 Grand Sport.

Photo: Sweet Spot 2

In addition to the new goodies under its composite skin, the C7 introduced a new design language to the Corvette canon. Gone are the smooth, rounded forms found on the the C5 and C6; in their place are angles and scoops and vents. While opinions on the new aesthetics are mixed, the C7 certainly looks far more aggressive than its immediate predecessors, as well as earlier models.

The Stingray convertible isn’t quite as menacing as the coupe, but it’s more attractive to our eyes. With the top down, it comes across as sleeker, smaller and more lithe. Just as important, removing the hard top’s roof does away with the chunky rear quarter windows, our least-liked aspect of the coupe design. Sure, it’s a shame to lose the coupe’s flowing roofline, but the convertible’s lightly sculpted rear deck, vestigial headrest fairings and rear spoiler don’t suffer in comparison. (With the top up, the C7 convertible reminds us a bit of the somewhat awkward C5 hardtop, with a slightly too-small greenhouse sprouting from the middle of a long body.)

Beyond the folding canvas top, reworked rear deck and associated changes, such as relocated top seatbelt mounts, and the traditional “waterfall” that flows from the deck down to the transmission tunnel, there’s only one visible difference between coupe and convertible: The air inlets located atop the coupe’s rear fenders have disappeared, replaced with ones underneath the car. When talking with Chief Engineer Juechter about that small change, he mentioned that it meant the convertible, unlike the coupe, wasn’t “track certified,” a phrase we’d heard a few times before. “We invented that term,” Juechter explains. “What it means is that a pro-level driver can jump into the car, go out onto a track all alone and go as fast as he can—so, turning qualifying laps—for 24 hours, with stops only for tires, fuel, food and sleep.”

Chevy actually does this test with all its cars, and while it may not be as rigorous as 24 hours of continuous driving, it’s much tougher than what the average owner would do to his or her C7 at a track day. According to Juechter, the reason the convertible does not make the cut (unlike the Stingray Z51 coupe, the Camaro Z/28, ZL1 and 1LE, and the V-series Cadillacs) is that its underbody ducts don’t provide enough airflow to the rear-mounted transmission and differential coolers to keep temperatures in check. That wasn’t really a concern during development, however. “With the convertible, we envisioned the owner going out, doing a couple of hot laps, and coming back to the pits,” Juechter explains. “Besides, you can’t do real track driving without a roll bar, anyway.”

Photo: Sweet Spot 3

Speaking of roll bars: The engineers considered fitting pop-up roll bars, like those used on the current Porsche 911 Cabriolet, but decided against it, for two reasons. “First of all, they’d increase mass,” says Juechter, who notes that the C7’s A-pillars have been beefed up to provide significantly more roll-over protection than Federal law requires. “Second of all, when we analyzed all the roll-over accidents of the C6, we realized they wouldn’t work. If you manage to roll a car like this, it’s going to be a high-speed, high-energy event, and you’re not going to roll over once; you’re going to flip up in the air and come down like an airplane crash.”

Dropping into the convertible’s cockpit is just like dropping into the coupe’s; we spotted no differences, not even the button that raises and lowers the roof. “It’s behind the steering wheel,” says Corvette Product and Marketing Manager Harlan Charles, who was showing us around a line of convertibles. “Now, this 3LT car has the optional suede on the A-pillars, as well as on the door panels, and that’s real carbon fiber on the dashboard….”

Corvettes have long been criticized for poor cabin design and materials, but Charles is very proud of the C7’s cockpit. “We were done with hearing all that,” he says. “We said, ‘We’re going to do it right.’”

They certainly did. Compared to the C6, the C7 features a much-improved interior. As we’ve reported, the seats, long a Corvette whipping boy, are now properly supportive, and the optional Competition Sport seats feature serious bolsters. The steering wheel is now top-notch, fully on par with those made in Germany or Italy. The materials, especially the optional ones, have noticeably raised the level of refinement in the cabin. While the C7 costs about the same as the C6, it definitely feels more expensive inside.

Photo: Sweet Spot 4

The fully automatic roof—a first for the Corvette—adds to that impression. Once you’ve found it, just press and hold the button down. (Alternately, press the relevant button on the key fob and watch the top drop with no one inside the car.) First, the rear deck panel just aft of the cabin motors up into the air. Next, the top unlatches itself from the windshield header, folds back and drops into a well. Finally, the elevated rear deck panel settles back down and locks in place. A loud beep lets you know when the 21-second process, which can be performed at speeds up to 30 mph, is complete.

With the top stowed, it’s time to push the engine stop/start button on the dash. The 6.2-liter V8 wakes up with a modest grumble, we slot the optional six-speed automatic transmission into Drive, wave good-bye to Charles and go.

It takes less than five minutes on Palm Springs’ surprisingly potholed roads to form three impressions that turn out to be lasting. The first is that the Stingray’s chassis is really stiff. Compared to the C6’s steel frame, the C7’s aluminum one is more than 50-percent stiffer (despite weighing 100 pounds less), and that’s evident in the way only the car’s suspension seems to be affected by the bumps and lumps; there are no creaks or rattles from the car itself.

Impression number two is that the LT1 has tons of torque. You can drive the C7 around with your big toe and still keep up with traffic. Push a little harder on the throttle and it pulls ahead. Plant your foot and it’s gone. While the engine’s 460 lb-ft of grunt is noticeable around town, we later discover that it plays an even bigger role on twisty backroads, where shifting from third to fourth, or fourth to third, or even fourth to second, proves mostly optional.

Photo: Sweet Spot 5

And the third lasting impression? The C7 convertible with the base suspension (referred to internally as FE1) isn’t a particularly soft-riding car. It’s not unduly firm in terms of overall ride quality, but rather than absorbing sharp bumps, the car passes a lot of them along to the driver, particularly at around-town speeds.

The flip side to this final impression is that, on the wonderfully winding mountain roads around Palm Springs, the Stingray convertible drives, as promised, just like the Stingray coupe. (As Charles puts it, “Even with the base suspension, the C7 is a still 1-g car.”) Quick turn-in? Check. Seemingly endless grip? Yep. Massively powerful brakes? Oh, yeah. Stupendous power on demand? You know it.

Interestingly, the FE1 Stingray works better the harder we push it. To our hands and butts, the car doesn’t feel entirely happy to be driven merely briskly. Driving at a six-tenths pace, we find ourselves sawing at the steering wheel in corners, making minor corrections to the car’s line, and stumbling over the brake pedal, which has a slight dead zone at the top of its travel that makes delicacy a challenge.

But when we up the pace a few notches, the base-suspension Stingray comes into its own. Pushing harder on the brake pedal reveals excellent feel and modulation. Loading up the superb Michelin run-flat tires clamps the Stingray onto our chosen line, and the C7 doesn’t relinquish its grip as we feed in the power—and more power, and more, until the g force is nearly pressing us against the door panel. When the traction control starts limiting the fun, we switch the DMS from Sport to Track mode, which frees up the rear end to move around a bit. As the turns come faster and faster, the C7 simply gobbles them up.

Photo: Sweet Spot 6

The six-speed automatic isn’t the ideal partner for this adventure, but it’s reasonably accommodating once we slot the gear lever into M (for manual). Doing so increases shift speeds and entirely locks out automatic gear changes; if you don’t use the shift paddles situated behind the steering wheel, the engine will simply run into, and stay on, its 6,600-rpm rev limiter. The automatic isn’t as responsive to our requests as a dual-clutch manual transmission, like Porsche’s PDK or Ferrari’s F1, so some forward thinking, and early shifting, is required. But what sounds like a negative actually adds, in some ways, to the experience; although we’re working a little harder, it’s very rewarding to time everything just right and roar smoothly through the turns.

Roaring is the proper description for the engine’s sound, too—so long as the car is equipped with the optional Dual Mode exhaust. So outfitted, the 6.2-liter V8 bellows deeply at low revs, then transitions to a higher-pitched howl as redline approaches. It also cackles and backfires sweetly when we get off the gas, and boosts engine output by 5 hp and 5 lb-ft. Even with the top down, however, the Dual Mode exhaust is never too loud for comfort. When we’re not pushing hard, the exhaust note is no louder than that of the standard item—which, frankly, is too quiet for our tastes, even around town.

We arrive back at home base with a big smile on our face. But the fun has only begun: There are still two other Stingrays to drive.

C7 convertible #2 is a very different beast. For starters, it has a seven-speed manual transmission and the Z51 Performance Package. The latter includes sportier FE3 suspension (e.g., stiffer springs and shocks, thicker anti-roll bars); 1-inch-larger front brake rotors; dry-sump engine oiling and a heavy-duty cooling system; different gear ratios and the aforementioned electronic limited-slip differential; taller wheels (8.5 × 19-inches front, 10 × 20-inch rear versus the base car’s 18s and 19s) and lower-profile tires (245/35ZR19s front, 285/30ZR20s rear, compared to the 40- and 35-aspect ratio base rubber); and different aero bits, including a full-width rear spoiler. Astonishingly, all these goodies raise the C7 convertible’s base price by less than $3,000, to $58,800.

Photo: Sweet Spot 7

We’re excited to sample the Z51 setup, but even more eager to test out this car’s optional Competition Sport seats. While the standard GT seats offer far more lateral support than those in the C6, the Competition Sport seats feature large upper-body bolsters that promise to better clamp us in place while we probe the car’s limits.

Jumping to the punch line: The Competition Sport seats deliver on their visual promise of providing more support without compromising comfort or ease of ingress or egress. As an added bonus, the $2,500 seat package includes “sueded microfiber wrap” on the seats, shifter and steering wheel. 

We wish our test car had been fitted with the optional heating and cooling functions—features that are option-group dependent, not seat dependent. Although the bun warmers would have been nice on our 45-degree Palm Springs day, it was hardly a sacrifice to go without them because the Stingray convertible does an excellent job of keeping the cold out of the cockpit when the top is down. Most air is sent over the tops of our heads, and the buffeting between the occupants—inevitable in convertibles without windblockers—is modest. Normal conversation is possible above 60 mph, and we didn’t have to raise our voices much to communicate up to around 100. With its top up, the convertible is almost as quiet as the coupe at normal speeds. Once into the triple digits, however, there’s far more wind noise emanating from the fabric roof.

In the twisties, the Z51 package proves just as desirable as the Competition Sport seats. Compared the base, FE1-suspension car, the Z51-equipped FE3-suspension Stingray feels more planted, more responsive and, well, faster. While it doesn’t offer noticeably more grip, it definitely allows us to better exploit that grip, with less nose dive under braking, faster turn-in and less lean in the corners—not that the base car leaned much to begin with. In short, Z51 makes the Stingray feel more like a full-on sports car, one that better connects the driver to the road and really encourages you to attack the turns with conviction.

Photo: Sweet Spot 8

There’s a price to be paid for the extra connection, however: The FE3 car’s ride is noticeably less comfortable than that of the base suspension. While this suspension setup isn’t too extreme, we do think it does make ride quality an issue for those who want to use their car regularly on less-than-perfect roads, or simply prefer to cruise around.

Likewise, the seven-speed manual transmission would be our pick, but it’s not for everyone. The C7’s clutch is heavy compared to a “normal” car’s, for example, as is its shifter. On the other hand, these require no more effort than in a C6, or any other American car boasting 450+ horsepower. Besides, that heft fits well with the Corvette’s character, and nicely matches the extra steering weight that arrives when the DMS is place in its Sport and Track modes.

This is a good time to mention one of the C7’s most interesting driver’s aids: Active Rev Match. This feature automatically blips the throttle during downshifts to match engine and transmission speeds, thus engaging the lower gear smoothly and quickly, without requiring the driver to be proficient in the black art of heel-and-toe shifting. In our experience, the system, which can be deactivated, works superbly. It can even be a boon to expert heel-and-toers: When hot-shoe Corvette racer David Ray drove a C7 Z51 coupe on track for last issue’s cover story, he couldn’t tell when Active Rev Match was on—the system just sat back and filled in any stray revs Ray didn’t request.

Active Rev Match aside, the 2014 Corvette’s cockpit provides an excellent environment for enjoying the “old school” manual transmission experience. The brake and accelerator pedals are properly placed for heel-and-toe shifting (if you’re so inclined) and the clutch is nicely sprung for hard launches and serious burnouts. While we initially kept bumping the large center console with our right elbow during shifts, we soon adapted and never thought about it again.

This time around, we arrive back at home base with an even bigger smile on our face. But there is still one Stingray left to sample, and we have a feeling it just might be the best one of all.

What was it that made C7 convertible #3 so appealing? In a word or four, Magnetic Selective Ride Control (MSRC). When these optional magnetorheological shock absorbers are combined with the Z51 Performance Package—the resulting suspension is referred to as FE4 (there’s no FE2)—there is a real increase in ride comfort and no detriment to handling.

Ordering MSRC along with Z51 is the ultimate no-brainer option. First, it offers better ride quality than the base suspension. Second, it absorbs bumps better than either the base or FE3 shocks. Third, its stiffness varies both depending on the Driver Mode Selector’s positioning—soft in Tour, firm in Track—and what the road underneath is doing. Finally, ordering both MSRC and Z51 gets you Performance Track Management, five distinct levels of traction- and stability-control intervention inside Track mode. The only downside to MSRC is that you have to pay extra for it, but that’s part of how Chevy keeps the base price down. Regardless, we don’t think there’s a better $1,800 you can spend to improve a Corvette.

We started this story with a question that it’s time to answer. Does the Stingray convertible deliver the best of both worlds, open-air excitement and coupe-like performance? Absolutely. There may be other cars with a $56,000 base price that offer 455 horsepower, but we guarantee none of them can deliver the full Corvette package of power, speed, handling and braking. And to our minds, that’s the real magic of the Stingray convertible.

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