Chevrolet Corvette Z06
Chevrolet introduced the most
track-capable Corvette in the brand's history - the 2015 Corvette Z06. It
stretches the performance envelope for Corvette with unprecedented levels of
aerodynamic downforce, at least 625 horsepower from an all-new supercharged
engine, and an all-new, high-performance eight-speed automatic transmission -
all building on the advanced driver technologies introduced on the Corvette
Stingray.
"The new Z06 delivers levels of performance, technology and design
that rival the most exotic supercars in the world," said Mark Reuss,
president, General Motors North America. "And the Z06 leverages the
engineering expertise of GM, offering the choice of two world-class
transmissions, supercar performance without supercar fuel consumption and
technologies that make it easier to fully enjoy the incredible experience of
driving it."
The 2015 model is the first Corvette Z06 to offer a supercharged engine, an
automatic transmission and, thanks to a stronger aluminum frame, a removable
roof panel. The new, supercharged 6.2L engine is expected to deliver at least
625 horsepower (466 kW), and can be matched with either a seven-speed manual or
an all-new, high-performance eight-speed automatic transmission with paddle
shifters for manual control. The aluminum frame carries over from the Corvette
Stingray and will be used essentially unchanged for the Corvette Racing C7.R.
A track-focused Z07 Performance Package adds unique components for true
aerodynamic downforce, Michelin Pilot Super Sport Cup tires for enhanced grip,
and Brembo carbon ceramic-matrix brake rotors that improve braking performance
and contribute to greater handling through reduced unsprung weight. Although
development testing is ongoing, the Z07 package has already recorded some of the
fastest lap times ever for a Corvette, surpassing even the ZR1.
"The Corvette Z06 is a great example of the technology transfer
between racing and production Corvettes," said Tadge Juechter, Corvette
chief engineer. "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."
Supercharged, efficient performance
The heart of the 2015 Corvette Z06 is the all-new LT4 6.2L supercharged V-8
engine, expected to deliver an estimated 625 horsepower (466 kW) and 635 lb-ft
of torque (861 Nm). To balance performance and efficiency, the LT4 leverages
the same trio of advanced technologies introduced on the Corvette Stingray:
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 supercharged LT4 engine delivers the greatest balance of
performance and efficiency ever in the Corvette," said John Rydzewski,
assistant chief engineer for Small-Block engines. "It is one of the
world's only supercharged engines to incorporate cylinder deactivation
technology, enabling it to cruise efficiently on the highway with reduced fuel
consumption, but offer more than 600 horsepower whenever the driver calls up
its tremendous power reserve."
To maintain the Z06's mass and performance targets, the LT4 engine was
designed with a more-efficient, 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 (25 mm) taller than the
Corvette Stingray's LT1 engine - while delivering nearly 37 percent more
horsepower and 40 percent more torque.
The new 1.7L Eaton R1740 TVS supercharger spins at up to 20,000 rpm - 5,000
rpm more than the supercharger on the Corvette ZR1's LS9. The rotors are
shorter in length, too, which contributes to their higher-rpm capability - and
enables them to get up to speed quicker, producing power-enhancing boost
earlier in the rpm band. That boost is achieved more efficiently, thanks to a
new, more direct discharge port that creates less turbulence, reducing heat and
speeding airflow into the engine.
The LT4 engine also has several unique features designed to support its
higher output and the greater cylinder pressures created by forced induction,
including:
Rotocast A356T6 aluminum cylinder heads that are stronger and handle heat
better than conventional heads
Lightweight titanium intake valves and machined connecting rods for reduced
reciprocating mass
High 10.0:1 compression ratio - for a forced-induction engine - enhances
performance and efficiency and is enabled by direct injection
Forged aluminum pistons with unique, stronger structure to ensure strength
under high cylinder pressures
Stainless steel exhaust headers and an aluminum balancer that are lighter
than their LT1 counterparts
Standard dry-sump oiling system with larger cooler capacity than Z51; used
with dual-pressure-control oil pump.
The LT4 will be built in Tonawanda, N.Y., and at the new Performance Build
Center in Bowling Green, Ky.
Eight speeds, no waiting
The supercharged LT4 is offered with a standard seven-speed manual
transmission with Active Rev Match, or an all-new 8L90 eight-speed paddle-shift
automatic transmission designed to enhance both performance and efficiency.
"Unlike most ultra-performance cars, the Corvette Z06 offers customers
the choice between two transmissions to suit their driving styles," said
Juechter. "The seven-speed gives the driver the control of a true
three-pedal manual transmission with perfect shifts enabled by Active Rev
Matching. The new eight-speed automatic offers drivers the comfort and
drivability of a true automatic transmission, as well as lightning-fast shifts
and manual control for track driving."
The seven-speed manual incorporates rev-matching technology for upshifts
and downshifts. This driver-selectable feature can be easily engaged or
disengaged via paddles on the steering wheel. The seven-speed is used with a
new dual-mass flywheel and dual-disc clutch, which deliver greater shift
quality and feel through lower inertia.
The eight-speed automatic is tuned for world-class shift-response times,
and smaller steps between gears keep the LT4 within the sweet spot of the rpm
band, making the most of the output of the supercharged engine for exhilarating
performance and greater efficiency.
For performance driving, the transmission offers full manual control via
steering wheel paddles, and unique algorithms to deliver shift performance that
rivals the dual-clutch/semi-automatic transmissions found in many supercars -
but with the smoothness and refinement that comes with a conventional automatic
fitted with a torque converter.
In fact, the 8L90's controller analyzes and executes commands 160 times per
second, and wide-open throttle upshifts are executed up to eight-hundredths of
a second quicker than those of the dual-clutch transmission offered in the
Porsche 911.
"There's no trade-off in drivability with the new 8L90 eight-speed
automatic transmission - it was designed to deliver performance on par with
dual-clutch designs, but without sacrificing refinement," said Bill Goodrich,
assistant chief engineer for eight-speed automatic transmissions. "It is
also the highest-capacity automatic transmission ever offered in a Chevrolet
car."
Featuring four gearsets and five clutches, creative packaging enables the
GM-developed eight-speed automatic to fit the same space as the six-speed
automatic used in the Corvette Stingray. Extensive use of aluminum and
magnesium make it more than eight pounds (4 kg) lighter than the six-speed.
Along with design features that reduce friction, the 8L90 is expected to
contribute up to 5-percent greater efficiency, when compared with a six-speed
automatic.
The eight-speed automatic will be built at GM's Toledo, Ohio, transmission
facility.
Designed for downforce
The performance targets of the Z06 also posed a challenge for the design
team, which had to create a striking design that also contributed to increased
capabilities.
"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 downforce for more cornering grip
and high-speed stability."
The design changes began not with the exterior panels, but the tires.
To deliver the levels of grip needed for the Z06's performance targets, the
Z06 was fitted with larger Michelin tires (Pilot Super Sport tires for the Z06;
Sport Cup 2 tires with the Z07 package). The P285/30ZR19 front tires are 1.5
inches wider than the tires on the Stingray, while the 335/25ZR20 rear tires
are two inches wider.
To cover the wider tire tread, the fenders of the Z06 were extended by 2.2
inches (56 mm) at the front, and 3.15 inches (80 mm) at the rear. These
extensions give the Corvette Z06 a wider, lower appearance further emphasized
by a unique rear fascia. It incorporates the same taillamp assemblies as the
Stingray, but on the Z06 the taillamps are pushed approximately three inches
farther apart, toward to edges of the body.
The tires are mounted on lightweight, spin-cast aluminum wheels that are
also wider than 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, which
are part of the design aesthetic:
The Z06 features two-piece steel rotors, measuring 14.6 x 1.3-inch (371 x
33 mm) front and 14.4 x 1-inch (365 x 25 mm) rear, with aluminum six-piston and
four-piston fixed calipers, respectively
The Z07 package adds larger, 15.5 x 1.4-inch (394 x 36 mm) front and 15.3 x
1.3-inch (388 x 33 mm) carbon ceramic-matrix brake rotors for consistent
performance lap after lap, and collectively save 23 pounds over the standard
Z06 rotors.
To harness the cornering and braking grip afforded by the larger tires and
brakes, the exterior of the Corvette Z06 is tailored to produce aerodynamic
downforce that presses the tires to the ground at high speeds.
The Z06 will offer three, increasing levels of aerodynamic downforce:
The standard Z06 features a front splitter, spats around the front wheel
openings, a unique carbon-fiber hood with a larger vent, and the rear spoiler
from the Corvette Stingray's Z51 Performance Package
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
wickerbill - a small, vertical tab at the edge of the spoiler that
significantly increases downforce
The available Z07 package add 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
downforce of any production car that 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
painstakingly designed to deliver the most possible airflow to the
supercharger's intercooler heat exchanger, so much 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 serve as air diffusers. The grille is complemented
with a larger hood vent, which vents hot air from the engine compartment and
contributes to downforce 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 elements include larger front fender vents and unique
air blades over the inlets on the rear fenders, which force about 50 percent
more air into the cooling ducts for the transmission and differential coolers
than those on the Stingray. To cope with the additional airflow, the Z06 has
also has 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.
Inside, the Corvette Z06 is distinguished from the Corvette Stingray by
unique color schemes that emphasize the driver-focused 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, which provides greater support on the track. The frame
structure for both seats is made of magnesium, for greater strength and less
weight than comparable steel frames. They're also more rigid, contributing to
the enhanced feeling of support during performance driving.
The Z06 also benefits from interior details designed for high-performance
driving, first introduced on the Stingray, including a steel-reinforced grab
bar on the center console for the passenger and soft-touch materials on the
edge of the console, where the driver naturally braces during high-load
cornering.
The performance-supporting elements inside the new Corvette Z06 are
complemented by unprecedented attention to detail and build quality. 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.
Track-proven technologies
The 2015 Corvette Z06 leverages the technologies introduced on the Corvette
Stingray, including the strategic use of lightweight materials and advanced
driver technologies, with unique features and calibrations tailored for its
capabilities.
"Our mission with the seventh-generation Corvette was to make the
performance levels more accessible, enabling drivers to exploit every
pound-foot of torque, every "g" of grip and every pound of
downforce," said Juechter. "It's a philosophy we introduced with the
460-horsepower Corvette Stingray - and one that's even more relevant with an
estimated 625 horsepower at your beck and call."
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 robust,
lightweight frame used on the Corvette Stingray and it 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. 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. It is 60
percent stiffer than the previous model with the roof panel installed.
The new Z06 retains the SLA-type front and rear suspension design of the
Corvette Stingray but uniquely calibrated for the higher performance threshold.
The third-generation Magnetic Selective Ride Control dampers are standard on
Z06. They can be adjusted for touring comfort or maximum track performance via
the standard Driver Mode Selector.
Like the Stingray, the Driver Mode Selector tailors 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, or 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. Its calibrations vary among three
modes, based on the Drive Mode Selector setting:
Mode 1 is the default setting for normal driving and emphasizes vehicle
stability
Mode 2 is engaged when electronic stability control is turned off in the
Sport or Track modes. This calibration enables more nimble turn-in and traction
while accelerating out of a corner
Mode 3 is automatically selected when Performance Traction Management is
engaged. This calibration has the same function as Mode 2, but is fine-tuned to
work with Performance Traction Management.
The new Corvette Z06 will be available in early 2015.
source:Chevrolet Press
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