We had no choice but to head to the track.
This 2011 Chevrolet Corvette Z06 Carbon is a hand-built prototype assembled from a 2010 Corvette Z06 and a big box of parts, so it couldn't be driven on public roads. It even came to us in a trailer complete with its own bodyguard from Chevrolet. So our only option was pretty much a track experience on the test asphalt at Auto Club Speedway and the winding road course at the Streets of Willow. Poor us.
Just to get a little perspective on the state of all things Corvette, we included the 2010 Chevrolet Corvette Grand Sport, which has all the things that we like about the Z06 Vette and none of the things we don't. And just as a baseline, we fronted up our 2002 Chevrolet Corvette Z06, a plain, $20,000 used C5 Vette that will kick rocks at just about any other car on the road.
The things we do for science.
Z07 + CFZ = Carbon (Almost)
Some 500 lucky people will take delivery this fall of a 505-horsepower 2011 Chevrolet Corvette Z06 Carbon, and while the cars won't carry unique VINs (which will compromise their collectability a bit), they will be very special.
Even if you're not in the lucky dog club, you can nearly duplicate the Carbon by ordering a 2011 Corvette Z06 with the $9,495 Z07 Performance package, which includes active suspension, staggered 19- and 20-inch wheels, Michelin Pilot Sport PS2 tires and Brembo carbon-ceramic brakes. And if you want to make it look right, you could add the $3,995 CFZ Appearance package, which includes a front aero splitter, rocker skirts, roof and ZR1-style spoiler (all made from carbon fiber). Adding just these stand-alone options to a 2011 Z06's base MSRP of $75,255 means you could build your almost-Carbon Z06 for just $88,745.
GM tells us that the prix fixe or a la carte carbonized versions of the track-ready Z06 will have MSRPs below that of the supercharged Corvette ZR1. We asked GM representatives if adding a $30,000 premium to the Z06's base price would be about right for a Carbon — say, $105,255 altogether. They'd only say that the Corvette Z06 Carbon will be priced above the standard 2011 Corvette Z06's $75,255 and below the 2011 ZR1's $110,750.
Cars No. 2 and 3
The 2010 Corvette Grand Sport, the second car in this Corvette-apalooza comparison test, carries a base MSRP of $55,720. It's in the test because our last encounter with the model was, well, sub-optimal, as the test car came up lame with a dislocated toe link on one wheel. We decided we'd give this 436-horsepower model of the Corvette C6 a do-over.
Finally, we brought out our own long-term test car, a 2002 Corvette Z06 that had yet to be tested because we'd spent months trying to resolve a detonation problem. After a couple months of fruitless, entertaining> and educational attempts to fix the pinging, we discovered the MAF sensor> had been damaged. Once it was repaired, a ping-free dyno test revealed we actually had one very healthy eight-year-old Z06. Originally rated at 405 hp, this C5 Vette makes a stout 382 hp at the rear wheels! Following a much-overdue alignment and now displaying over 45,000 miles on its odometer, our Z06 was ready to show what the old school could do.
Z06, the Elder
Enough introductions, let's stand on the skinny pedal. After just one launch with our Quicksilver Metallic 2002 Z06, it was obvious that the trick to getting the most out of the veteran Vette would be traction management. While Team Corvette has just announced major improvements are in store for its preferred Goodyear Eagle F1 Supercar tires, nothing could be done for these vintage examples because they were toast.
But get the launch right with a wisp of wheelspin and this old street fighter still packs a punch. The 60-mph mark arrives in just 4.5 seconds from a standstill (4.2 seconds with 1 foot of rollout) and the quarter-mile roars by (literally) in 12.5 seconds at 116 mph, just like it did when the Z06 was new in 2002. We don't care what you say, our old Z06 is still fast — and it sounds fast, too. Our sound meter reports that this 2002 Z06 with its 26-pound titanium exhaust system is even louder inside the car at wide-open throttle than either the 2010 Corvette Grand Sport with its $1,195 dual-mode exhaust flappers or the 2011 Z06 Carbon's new X-pipe setup.
Standing on the Z06's rock-hard brake pedal produces mixed results. It requires at least 120 feet (about 15 feet longer than when new) to come to a halt from 60 mph, but the car shows decent fade resistance as it makes its shortest stop on the sixth attempt. Again, it's those tires. Surely the skid pad would reveal how little ultimate grip remained in the weary run-flats, and we were right. At 0.92g of lateral acceleration, the result shows some decline from the 1.0g a car like this could post in 2002.
A slalom test with a Corvette is the bane of any driver who is not former Corvette development engineer (and racer) John Heinricy. Our Z06 proved twitchy in typical Corvette style and indeed one brief slide could not be caught with a dab of opposite lock and the car produced a cotton-scrunching 70-mph tank slapper. For the remainder of the runs, we chose 4th gear instead of 3rd to mellow the effects of the throttle on weight transfer. It mostly worked, as the Z06 posted a 68.8-mph pass, just a bit more than 1 mph slower than this model's result when new.
As our test driver said after finishing this portion of the track test and anticipating the next day's adventure on a road circuit, "I know I should be looking forward to driving three Corvettes on a racetrack tomorrow, but after today, I'm not so sure about this car. I'll give it my 98 percent effort and reserve 2 percent just in case."
Grand Sport, the Do-Over
We decided not to dabble with the launch control of the 2010 Chevrolet Corvette Grand Sport this time, yet we duplicated our straight-line data from our previous test, though with a bit less consistency. About 3,000 rpm gets the necessary chatter from the Z06-size 325/30ZR19 rear tires, while this car's Tremec TR-6060 six-speed manual transmission (a more highly evolved version of the Tremec T-56 in our 2002 Z06) ensures the shifts go smoothly from gear to gear within the relatively narrow gates.
The best run shows a 0-60-mph time of 4.5 seconds from a standstill (4.2 seconds with 1 foot of rollout) and a quarter-mile of 12.5 seconds at 115.1 mph. You'll find our 2002 Z06 and the 2010 GS neck-and-neck across the entire run — to the tenth of a second — with the old car 1 mph faster over the last 66 feet. It turns out that the 436-hp 2010 GS has to move 3,348 pounds of sports car, while the 405-hp '02 Z06 has to motivate just 3,116 pounds, so each must power 7.7 pounds with each horse. No wonder the results are nearly identical. How 'bout them apples, Newton?
This 2010 GS's suspension proved up to the task on the skid pad and in the slalom this time. Its 0.98g skid pad performance comes more predictably than the former 0.96g result, while the car also seems more trustworthy with its 69.7-mph dance between the cones than the previous 68.8 mph. The GS now proves communicative, and we could confidently explore its limits thanks to its quick turn into each cone and the ability to throttle-steer the rear of the car.
Did we just say that about a Corvette?
Z06, the Prodigal Son
After watching its handler back the priceless prototype out of the trailer (with only 2 inches to spare on either side), we put the Z06 Carbon onto the scales to discover it weighs 3,210 pounds, or exactly 17 pounds more than the 2008 Corvette C6 Z06 with 505-hp 7.0-liter V8 we tested. The Z06 Carbon's larger wheels and tires must be a little heavier than those of a standard Z06, but the carbon-fiber hood, fixed roof and carbon-ceramic brakes must be a little lighter.
Since the Z06 Carbon has Michelin PS2 tires, two-mode magnetorheological suspenders and six-piston front and four-piston rear Brembo calipers just like the ZR1, we were expecting the Z06 Carbon to stop like a ZR1, and so it did to the very foot, with a 96-foot stop from 60 mph. Because the 15.5-inch composite front brake discs require some heat to work optimally, our best stop arrived on the seventh attempt. And no doubt the Z06 Carbon's 285/30R19 front tires (nearly the same size as the 2002 Z06's rears) should also take credit.
The 335/25R20 rear tires of the 2011 Z06 Carbon are only slightly smaller than the 345/30R19 Michelins of our long-term Dodge Viper. Just shy of 3,000 rpm did the trick for a good launch, but the car didn't prove to be quite as quick to 60 mph as we had hoped.
Later data analysis showed that the Z06 Carbon's 1-2 shift is initiated at redline and lasts 0.23 second, but since it occurs at 59.6 mph, it slows the acceleration to 60 mph from a standstill to 4.2 seconds (3.9 seconds with 1 foot of rollout). Further down the track, this Z06 also needs to grab 4th gear before hitting the V8's redline of 7,000 rpm, so it crosses the quarter-mile mark in 11.8 seconds at 123 mph. The 2008 Z06 was able to accomplish the same 1-2 shift at 61.2 mph, enabling it to reach 60 mph from a standstill in 3.9 seconds (3.6 seconds with a 1-foot rollout) and it remained in 3rd gear to cross the finish line in 11.7 seconds at 123.2 mph. (You can see a visual comparison in a chart on display in the photo gallery.)
We anticipated the ZR1-fortified Z06 Carbon would destroy the 600-foot course at well over 70 mph since the ZR1 with the same tires, wheels and active suspension blasts through at 74.7 mph. Yet the best we can muster with the Z06 Carbon when the stability control is off is 70 mph. This car's steering feels lightly vague, and the car doesn't offer the confident turn-in and front-end bite we experience in the Grand Sport. We finally managed a run of 71.3 mph with the stability control on while sawing madly at the disinclined steering wheel.
(We tried to verify with GM if these discrepancies could be explained by the Carbon's active suspension or any other differences in hardware, but the Corvette engineers reported that the steering racks of the two cars are identical and further insisted that our impressions of the two cars should be reversed. Hmmm, sounds to us like prototype engineering might be the culprit.)
On the other hand, the Z06 Carbon's 1.04g performance on the skid pad is on par with the ZR1's 1.06g. There are only a couple of cars that can produce such impressive centripetal performance.
The next afternoon, we arrived at the Streets of Willow set up in its clockwise 1.8-mile configuration, and we were ready to separate fast-on-paper from fast-on-track.
First up, the 2002 Z06.
With its tires turned hard and slick by at least four burnout sessions while in our care, we didn't expect much from the old beast on a road course. It proved to be an equal-opportunity offender, offering equal amounts of understeer and oversteer, what we call "pushy-loose." Though it doesn't deliver much confidence on the racetrack, the results are pretty impressive, with a best time of 1:30.35 and a 105.4-mph Vmax. That's faster than a 2008 BMW M5.
Take that, you 500-hp, V10-powered flappy-paddle-gearbox Euro super sedan.
OK, the 2010 Chevrolet Corvette Grand Sport looks like a Z06 and even has the Z06's rolling stock, but it's propelled by only a 436-hp, 6.2-liter V8. So what happens when the Grand Sport is asked to put all that bravado to work on a racetrack?
First of all, the improved support from its driver seat (a small part of the $7,705 4LT Premium package) must account for a few tenths, but it's the delicate and communicative steering that impresses us most. "I can place this car inch-perfect on the track," our driver reports. "I don't know what they did with it, but this is unlike any previous Corvette I've driven. Even the screamin' Eagles [tires] are working."
Sure, there is still some of that sway from the rear that a Corvette is prone to exhibit, but the motion settles down after one oscillation so it never becomes an issue. With fresh tires and trustworthy brakes, the Grand Sport manages to slice more than 3 seconds from the 2002 Z06's lap with a 1:27.29 time and a top speed of 109.9 mph. No matter what the power-to-weight ratio might be, a proper chassis setup counts for something.
We were all impressed with how competent this Grand Sport package proves to be. The engine, transmission, brakes, steering and grip are all up to the task. While its options might be expensive, the result is solid performance.
Z06 Alla Carbonara
The 2011 Chevrolet Corvette Z06 Carbon is the whole reason we cranked up Corvette-apalooza. Would the Z06 Carbon Edition have the poise of the Grand Sport but with even more firepower and higher limits?
For starters, this 505-hp, 7.0-liter V8 sounds more like a NASCAR V8 than anything we've ever heard. Power? Yeah, everywhere in the rev range up to 7,000 rpm. Fancy dampers with fluid that can alter its viscosity based on the road conditions and your driving style? Got 'em. Just about the widest and best street-legal tires available, plus brakes that rival anything in the world? Roger that.
Between Lap One and Lap Two, the in-car radio crackles to life: "This thing is an animal! It's literally eating this track up like a racecar. I know I can brake deeper now that the brakes are warmed up, and I'm switching the suspension from Sport to Touring to see if it gives the car better compliance over the bumps."
The car's reluctance to steer quickly into a corner proved less of an issue on the road course than in the slalom, while the brakes were simply amazing and would stand the car on its nose like a sideshow contortionist. The Touring setting does indeed enable the Z06 Carbon to soak up pavement imperfections, but it also makes the car grip better on the patchwork.
Yet it's the way this ZR1-fortified Z06 is able to put its prodigious power down to the pavement on the exit of a corner that really separates it from the standard Z06. Sure, you need to exercise delicacy on the throttle, but we found that we could almost mash the go pedal to the floor as the steering wheel unwound toward center while the car accelerated.
Lap Two proved to be the fastest, at 1:24.28 with a 115.3-mph top speed. The lap not only shaved 3 seconds from the GS's best time, but it also represented an advantage of 0.81 second and 3.2 mph over the performance of the Nissan GT-R. Of course, the 638-hp ZR1 still holds the official lap record at 1:23.87 with a Vmax of 117.1 mph.
A New Standard
We have no qualms declaring the 2010 Chevrolet Corvette Z06 Carbon Edition the best Corvette money can buy. You might suggest that the ZR1 represents a better deal since you get 133 hp more for just $5,495 more. But here's the deal.
The Porsche 911 GT2 is more powerful and both quicker and faster on a drag strip (and more expensive) than a Porsche 911 GT3, yet we still prefer the immediacy of the GT3's naturally aspirated engine, its linear power delivery and the overall cohesive personality of the chassis. The same goes for the Corvette Z06 Carbon.
Like the Porsche 911 GT3, the Corvette Z06 Carbon embodies core values and fundamental virtues; it is the ultimate expression of the model. You can choose a slower version, a faster version, a convertible and so on (there will be seven different Corvette models to choose from in 2011), but the decision will always turn on the inherent goodness that the Z06 Carbon represents.
The manufacturer provided Edmunds two of the vehicles for the purposes of this evaluation. Edmunds owns and maintains the 2002 Chevrolet Corvette Z06.
Senior Road Test Editor Josh Jacquot says:
Pretend for a minute that this is a one-car test. Ignore our old-school Z06. Ignore the Grand Sport. Because for me there's only one car that matters here: the 2011 Corvette Z06 Carbon.
This (finally) is the car I've always wanted the Corvette to be. Certainly the ZR1 is incredible. But its power is just plain silly. And unless you live your life at triple digits, its power advantage over the Z06 is purely symbolic.
The Z06's 505-horsepower, 7.0-liter V8 is more than adequate and always has been. Still, until now, I've never been passionate about driving the Z06. Wind up the cornering loads and toss in some midcorner bumps and the Z06's rear end would throw in the towel with frightening regularity. It wasn't fun. The ZR1 with its Magnetic Selective Ride Control solved this problem completely, and I always hoped the technology would find its way downstream.
And now, finally, it has.
This Z06 Carbon is the best of both worlds — perfectly controlled body motions and superb ride quality. Add in carbon-fiber bodywork, carbon-ceramic brakes, superb rubber and a huge American V8 good for 7,000 rpm and you've got one badass Vette. And guess what all that adds up to on a racetrack? Confidence — confidence like I've never experienced in a Corvette until now. It is absolutely the fastest car I've ever driven around the Streets of Willow Springs, a racetrack I know better than any other.
Lightweight, normally aspirated, focused and fast, the Z06 Carbon Edition is to the Corvette world what the GT3 is to the Porsche 911 world. It is the driver's car I've always wanted the Corvette to be. And it's the only one worth discussing here.
||2002 Corvette Z06
||2010 Corvette Grand Sport
||2011 Corvette Z06 Carbon Prototype
Were this the usual Inside Line competition with the winner chosen by our automated point-tabulating "megachart," the overwhelming winner would have been our long-term test car, the 2002 Chevrolet Corvette Z06 we bought for just $20,000.
Neither the 2010 Chevrolet Corvette Grand Sport nor the 2011 Chevrolet Corvette Z06 Carbon Limited Edition prototype could dig themselves out of value-weighted holes they found themselves in with as-tested prices $50,000-$90,000 greater.
Because of its estimated cost, the 2011 Z06 Carbon started deep in a 448.3-point pit and the 2010 GS would have to rise above a similarly arduous 249.3-point well just to be on even ground with the 8-year-old Corvette. That's how a bean counter would choose a Corvette, not us.
But once you ratchet down the "Price" component of the overall points comparison to a weighted value of zero percent, the finishing order literally reverses. The winner then becomes the 2011 Z06 Carbon Prototype with a score of 76.1 points. Second place remains the 2010 Grand Sport with 68.5 points. And the 2002 Z06 picks up only 51.2 points for a last-place finish.
Personal Rating (2.5%): Purely subjective. After the test, each participating editor was asked to rank the vehicles in order of preference based on which he or she would buy if money were no object and he or she had unlimited access to a racetrack at no personal cost.
Recommended Rating (2.5%): After the test, each participating editor was asked to rank the vehicles in order of preference based on which he or she thought would be best for the average Corvette enthusiast shopping in this segment.
20-Point Evaluation (25%): Each participating editor ranked the three cars based on a comprehensive 20-point evaluation. The evaluation covered everything from exterior design to cupholders. Scoring was calculated on a point system, and the scores listed are averages based on all test participants' evaluations.
Feature Content (15%): For this category, the editors picked the top 12 features they thought would be most beneficial to increasing the score for either/both the 2010 Corvette Grand Sport and 2011 Corvette Z06 Carbon prototype. For each vehicle, the score was based on the number of actual features it had versus the total possible (12). Standard and optional equipment were taken into consideration.
Performance Testing (25%): All three cars were put through a comprehensive battery of instrumented tests, including 0-60-mph acceleration, quarter-mile runs and panic stops from 60 mph. They were also run through a 600-foot slalom course to test transitional handling and around a skid pad to determine ultimate grip. The vehicles were awarded points based on how closely each came to the best-performing vehicle's score in each category.
Fuel Consumption (15%): The numbers listed were the result of a simple percentage calculation based on the EPA's "Combined" fuel-economy estimates for the cars in the comparison test. Assigning 100 to the most fuel-efficient vehicle, the less efficient vehicles received a resulting percentage value.
Price (15%): The numbers listed were the result of a simple percentage calculation based on the least-expensive vehicle in the comparison test. Using the "as tested" prices of the actual evaluation vehicles, the least-expensive vehicle received a score of 100; the other vehicles received a score based on a percentage of the others' actual cost.