Images: Courtesy GM
2015 is only mere days away, and once again, GM has hit us with the perfect Christmas gift. They just announced that the Z06 rejoins the Corvette lineup for 2015. According to them, this is the most capable model in the iconic car’s 62-year history. It not only stretches the performance envelope for Corvette with its unprecedented levels of aerodynamic down force, the fact that it is the first Corvette Z06 to offer a supercharged engine, with an eight-speed paddle-shifted automatic transmission it tore it to shreds. The new supercharged 6.2-liter V-8 engine (designated LT4) is SAE-certified to deliver 650 horsepower at a life-extending 6,400 rpm, and a tire shredding 650 lb/ft. of torque at 3,600 rpm. Those numbers make the 2015 Corvette Z06 GM’s most powerful production car. For the first time since 1963, the Z06 is also offered in coupe and convertible versions. Building a modern Z06 as a convertible was only enabled by recent technological advancements. According to Corvette chief engineer Tadge Juechter: “Simply put, until recently it was not possible to create an open-roof structure [that was] strong enough to meet Corvette’s performance levels. It required advancements in computer-aided engineering, metallurgy and manufacturing – many of which did not exist five years ago – to make a frame strong enough for a Z06 Convertible.”
The aluminum structure is a whopping 20-percent stiffer than that of previous years’ fixed-roof Z06. As hard as it might be to believe, there are no structural reinforcements needed for the Z06 convertible. Because of that, it has a nearly identical curb weight as the Z06 coupe. They also share the same chassis tuning, powertrain output, driver technologies and equipment options – including a track-focused Z07 Performance Package. The Z07 package gets the performance-minded driver adjustable front and rear aero components, Michelin Pilot Super Sport Cup tires, and Brembo carbon ceramic-matrix brake rotors that improve braking performance and contribute to greater handling through reduced unsprung weight. “The Corvette Z06 is a great example of the technology transfer between racing and production Corvettes,” said Juechter. “First, we took what we learned on the Corvette Racing C6.R and applied that to the all-new Corvette Stingray. Then, using the Stingray as a foundation, the Z06 and C7.R were developed to push the envelope of performance on the street and the track.”
To deliver the Z06’s performance targets, the car was fitted with larger Michelin Pilot Super Sport tires for the Z06, (Sport Cup 2 tires with the Z07 package). The P285/30ZR19 front tires are 1-1/2-inches wider than the tires on the Stingray, while the 335/25ZR20 rear tires are 2-inches wider. Since there is a lot of tire to cover, the fenders of the Z06 were extended by almost 2-1/4-inches at the front, and just over 3-inches at the rear. These extensions give the car a wider, lower stance, further emphasized by a unique rear fascia. The rear fascia incorporates the same tail lamp assemblies as the Stingray, but on the Z06, the tail lamps are pushed approximately three inches farther apart. “Practically every exterior change served a functional purpose, as this beast needed more of everything,” said Tom Peters, Corvette design director. “The flared fenders accommodate larger, wider wheels and tires for more grip.
The larger vents provide more cooling air to the engine,brakes, transmission, and differential for increased track capability. The more aggressive aerodynamic package generates true down force for more cornering grip and high-speed stability.” Since we mentioned the tires, we need to tell you that they are mounted on lightweight, spin-cast aluminum wheels that are also wider than those on the the Stingray (19 x 10 inches in front and 20 x 12 inches in the rear). Their open, ultralight design showcases the massive Brembo brakes. The brakes on the Z06 feature two-piece steel rotors that measure 14.6 x 1.3-inches up front, and 14.4 x 1-inch on the rear. With aluminum six-piston and four-piston fixed calipers, respectively The Z07 package adds larger, 15.5 x 1.4-inch front and 15.3 x 1.3-inch carbon ceramic-matrix brake rotors for consistent performance lap after lap, and collectively, saves 23 pounds over the standard Z06 rotors. To harness the cornering and braking grip created by the larger tires and brakes, the exterior of the Corvette Z06 is tailored to produce increased aerodynamic down force.
For those of you that like choices, the Z06 offers three increasing levels of aerodynamic down force-increasing packages: The standard Z06 features a front splitter, spars around the front wheel openings, a unique carbon-fiber hood with a larger vent, and a rear spoiler. An available carbon-fiber aero package – in either black or a visible carbon-fiber finish – adds a carbon fiber front splitter with aviation-style winglets, carbon fiber rocker panels, and a larger rear spoiler with a fixed wicker bill, which combine to create true aerodynamic down force. The available Z07 package adds larger winglets to the front splitter, along with an adjustable, see-through center section on the rear spoiler for track use. With this package, the Corvette Z06 delivers the most aerodynamic down force of any production car GM has tested.
The exterior design also reflects the increased cooling required for the new Corvette Z06. For example, the mesh pattern on the front fascia was designed to deliver airflow to the supercharger’s intercooler. It works so well, that the mesh grill directs more air into the engine bay than if the grille was removed. The unique grille also features dedicated brake-cooling intakes, and wider grille outlets on the bottom of the car serve as air diffusers. The grille is complemented with a larger hood vent, which vents hot air from the engine compartment and contributes to down force by allowing air driven through the grille to exit through the hood rather than being forced under the car, which could create lift. Additional cooling is aided by larger front fender vents and unique air blades over the inlets on the rear fenders of the coupe, which forces about 50-percent more air into the transmission and differential coolers than those on the Stingray (convertible models feature under-body inlets).
To cope with the additional airflow, the Z06 coupe and convertible also have larger rear-fascia openings than the Stingray. Standard front and rear brake-cooling ducts, including Z06-signature rear ducts integrated in front of the rear fender openings, are also part of the functional design changes over Stingray models. Again, iof you like choices, ten exterior colors are offered: Laguna Blue Tintcoat, Daytona Sunrise Orange Metallic, Velocity Yellow Tintcoat, Arctic White, Blade Silver Metallic, Black, Shark Gray Metallic, Crystal Red Tintcoat, Torch Red and Night Race Blue Metallic. The convertible is a fully electronic top that can be lowered remotely using the car’s key fob. The top can also be opened or closed on the go, at speeds of up to 30 mph. A thick fabric top is offered in four colors. Behind the seat backs, dual Carbon Flash-painted or available carbon fiber accent panels enhance the character lines of the tonneau cover. Corvette Stingray’s signature “waterfall” design originates in the valley between the nacelles, bringing the exterior color into the interior.
Inside, the Z06 is distinguished from the Stingray by unique color schemes that emphasize the cockpit, and a unique, flat-bottomed steering wheel. Like the Stingray, the Z06 will be offered with two seating choices: a GT seat, for all-around comfort, and a Competition Sport seat with more aggressive side bolstering. The frame structure for both seats is made of Magnesium, for greater strength. They’re also more rigid, contributing to the enhanced feeling of support during performance driving.
Several trim combinations are offered for the seats: 1LZ: GT seats with perforated Mulan leather seating surfaces or Competition Sport seats with leather seating surfaces and sueded microfiber inserts. 2LZ: GT or Competition Sport seats with perforated Mulan leather seating surfaces; GT or Competition Sport seats with leather seating surfaces and suede microfiber inserts. 3LZ: GT seats with perforated Napa leather seating surfaces; Competition Sport seats with perforated Mulan leather seating surfaces; GT or Competition Sport seats with leather seating surfaces and suede microfiber inserts. All models feature a fully-wrapped interior, where every surface is covered with premium, soft-touch materials. Available materials, depending on the trim level, include Napa leather, aluminum, carbon fiber and micro-suede.
There’s even a micro-LED screen for the passenger’s climate control placed below the vent on the dash, away from the performance features on the instrument panel. Inside, this is not just a performance car. Certain amenities are demanded by discerning owners, so, for starters, a new Performance Data Recorder (included with the available navigation system), is housed within an 8-inch-diagonal color touch radio with Chevrolet MyLink—which is standard on all trim levels (a navigation system is standard on 3LT and available on 1LT and 2LT). Zo6 also comes with a Bose® nine-speaker premium audio system that is standard with 1LZ. A Bose® 10-speaker premium audio system – with bass box – is standard on 2LZ and 3LZ. Your choice of interior colors are Dark Gray, Blue, Jet Black, Kalahari, and Adrenaline Red. The heart of the 2015 Corvette Z06 is the all-new LT4 6.2-liter supercharged V-8. To balance performance and efficiency, the LT4 leverages direct injection, Active Fuel Management, or cylinder deactivation, and continuously variable valve timing. These technologies – combined with the fuel-efficient multi-speed transmissions, aerodynamic design and lightweight construction – help make the new Z06 surprisingly fuel efficient. The LT4 engine was designed with a more-efficient and more-compact supercharger. Even with its integrated supercharger/intercooler assembly mounted in the valley between the cylinder heads, the engine is only about one inch taller than the Corvette Stingray’s LT1 engine. But, the LT4 delivers nearly 37-percent more horsepower, and 40 percent more torque. The new 1.7-liter supercharger rotors are smaller in diameter, which contributes to their higher-rpm capability. This enables them to produce boost earlier in the rpm band. That boost is achieved more efficiently via a more direct discharge port that creates less turbulence, reducing heat and increasing airflow velocity into the engine. If you like shifting your own gears, the seven-speed manual incorporates rev-matching technology for upshifts and downshifts. This driver-selectable feature can be engaged or disengaged via paddles on the steering wheel.The eight-speed automatic is tuned for impressive shift-response times, and smaller steps between gears to keep the LT4 within the sweet spot of the rpm band.For the first time ever, the Corvette Z06’s aluminum frame will be produced in-house at General Motors’ Bowling Green assembly plant. It’s the same lightweight frame that is used on the Corvette Stingray, and will be used essentially unchanged for the C7.R race cars. The stiffer design of the aluminum frame allows the Corvette Z06 to be offered with a removable roof panel for the first time.
Even with the lightweight, carbon fiber roof panel removed, the new Corvette Z06 offers 20-percent more structural rigidity than the previous model’s fixed-roof design. With the roof panel installed, it is 60-percent stiffer than the previous model. Like the Stingray, the Driver Mode Selector delivers up to a dozen features of the Z06 to suit the driver’s environment, including: Launch control: Available in Track mode for manual and automatic transmissions, providing maximum off-the-line acceleration. Active handling (StabiliTrak electronic stability control): A “competitive” setting is available in Track mode and is more suited for on-track conditions. It can also be disabled, giving the driver complete control. Traction control: Weather mode tailors traction control and engine torque for driving in inclement conditions. Performance Traction Management: Available in Track mode and offers five settings of torque reduction and brake intervention for track driving. Electronic Limited Slip Differential: Adjusts the rate at which the limited slip engages, to balance between steering response and stability in different driving conditions with more aggressive performance in Sport and Track modes. The smart electronic limited-slip differential (eLSD), is standard on the Z06 to make the most of the torque split between the rear wheels. The system features a hydraulically actuated clutch that can infinitely vary clutch engagement and can respond from open to full engagement in tenths of a second. It shifts torque based on a unique algorithm that factors in vehicle speed, steering input and throttle position to improve steering feel, handling balance and traction. The eLSD is fully integrated with Electronic Stability Control and Performance Traction Management systems.