MORE THAN PERFORMANCE: CORVETTE ZR1’S CHASSIS AND
SUSPENSION DELIVER A CONFIDENT, COMFORTABLE DRIVING
EXPERIENCE
DETROIT – Its supercharged engine twists out more than 600
horsepower and nearly 600 lb.-ft. of torque. Its
racing-inspired dual-disc clutch channels that power to a
set of massive, 20-inch by 12-inch rear wheels, helping
push the ZR1 to more than 200 mph (320 km/h). It also
corners with the grip of a hungry Kodiak bear – delivering
more than 1g of lateral acceleration – and stops with
exceptional immediacy.
Yet for all its astounding performance attributes, the 2009
Corvette ZR1 has a refined driving experience that makes it
a daily-driveable supercar.
“The ZR1 is a car anyone can drive confidently and
comfortably,” said Tom Wallace, vehicle line executive.
“From the very beginning, refinement, balance and
compliance were targets that were as important as the car’s
maximum performance.”
More than simply scaling wheel, tire and brake sizes to
match the powertrain’s output, the ZR1’s engineers
harmonized the chassis and suspension components to deliver
a ride quality and driving experience that is unmatched by
most supercar competitors. Enabling elements include
standard Magnetic Selective Ride Control and new, Michelin
Pilot Sport 2 tires that were developed specifically for
the car.
“The ZR1 corners better than the Z06, but has ride
compliance more like the base coupe,” said Tadge Juechter,
Corvette chief engineer. “Every element from the
stabilizer-bar diameters to the composition of the tires
was carefully matched to deliver a balanced driving
experience – it’s a supercar that doesn’t sacrifice ride
quality for performance.”
Stopping power is derived from a carbon-ceramic-based brake
system that is lightweight, heat resistant and wear
resistant. While delivering braking performance similar to
a racecar, it helps reduce the unsprung mass that the ZR1
would have accrued through the use of similarly sized cast
iron brake rotors.
“It wasn’t enough to achieve the braking requirements
commensurate with the car’s performance – we needed to find
a solution that minimized the impact on the car’s balanced
feel,” said Juechter. “A larger brake package generally
means more weight, but the carbon-ceramic rotors deliver
excellent performance while also minimizing unsprung
weight.”
Lightweight
structure
The ZR1 has an aluminum structure for optimum stiffness and
low mass. It is the same structure used on the Z06, but
with specific body panels and drivetrain components mounted
to it.
The chassis is constructed with perimeter rails made of
strong, single-piece hydroformed aluminum members featuring
cast suspension nodes. Other castings, stampings and
extrusions are combined into the structure with
state-of-the-art manufacturing technologies. Advanced
structural composites featuring carbon-fiber are bonded to
the aluminum structure. The passenger compartment floors,
for example, combine carbon-fiber skins with an
ultra-lightweight balsa wood core.
Like the Z06, the ZR1 has a magnesium cradle that serves as
the attachment point for the engine and some front
suspension components, with the new LS9 engine sitting
slightly lower in the chassis than the Z06’s LS7 engine.
Magnesium is lighter than aluminum yet incredibly strong.
The magnesium cradle helps improve the front-to-rear weight
distribution, as do the carbon-fiber front fenders, hood
and wheelhouses.
To optimize the weight balance, the battery is located in
the rear cargo area, behind the right rear wheel.
Suspension
tuning and Magnetic Selective Ride
Control
The ZR1 retains the 105.7-inch (2,686-mm) wheelbase of
other Corvette models, as well as the short-long arm
suspension and transverse spring design, but it rides on
all-new, wider wheels and tires, stops with carbon-ceramic
brakes and features specific spring and stabilizer bar
rates – the largest-diameter stabilizer bars available on a
Corvette. Also, the axle half-shafts are angled more
horizontally to align with the different geometry created
by the ZR1’s larger-diameter and wider rear wheels.
Magnetic Selective Ride Control (MSRC) is standard and
tuned specifically for the ZR1. It is a real-time damping
system that replaces conventional mechanical-valve shocks
with electronically controlled shocks filled with a
synthetic fluid containing minute iron particles. Under the
presence of magnetic charge, the iron particles align to
provide damping resistance almost instantly.
MSRC “reads” the road in 1-milisecond intervals (a thousand
times per second), making it the world’s fastest-reacting
damping system. Its ability to deliver a compliant ride
with nearly instantaneous damping adjustments enabled
engineers to develop a surprisingly supple ride quality in
a supercar that still delivers cornering grip of more than
1g.
“The damping control of MSRC allowed for front and rear
springs that have a slightly lower rate than the Z06, which
enhances the car’s ride quality,” said Juechter.
From a high-performance perspective, Magnetic Selective
Ride Control helps the rear axle remain planted during
launch for smooth, hop-free acceleration. It also helps
suppress axle movement when cornering on broken or uneven
pavement.
With cornering capability greater than the Z06, the ZR1’s
powertrain was upgraded with a higher-capacity oil pump and
larger-capacity oil reservoir. This ensures optimal oil
pressure during the highest-load driving maneuvers.
Carbon-ceramic
brakes
The ZR1 comes standard with carbon-ceramic brake rotors and
large-capacity calipers at all for corners. The exotic
carbon-ceramic rotors are made of a carbon-fiber-reinforced
ceramic silicon carbide material, which offers low mass and
exceptional resistance to wear and heat.
The vented and cross-drilled rotors on the ZR1 measure 15.5
inches (394 mm) in diameter in the front and 15 inches (380
mm) in diameter in the rear – making them among the largest
carbon-ceramic rotors available on any production vehicle.
And while large in size, they are low in mass, saving
approximately 11 pounds (5 kg) per corner over comparably
sized cast iron rotors.
The rotors are acted upon by six-piston front calipers and
four-piston rear calipers, each painted a ZR1-exclusive
blue. The front pads are equivalent in size to the largest
on any production car with a single-pad design, measuring
148 sq. cm. in surface area – double that of the Corvette
Z06’s 70-sq.-cm. front pads.

Braking performance of the ZR1 is nothing short of
phenomenal, with the carbon-ceramic rotors and large
calipers combining to provide exceptionally short,
fade-free stopping during high-performance driving. The
composition and durability of the non-metallic
carbon-ceramic materials means the rotors should never show
any corrosion or require replacement for the life of the
vehicle, when used in normal driving.
A new, Bosch brake-apply system is standard and includes
the brake master cylinder, booster and ABS control module.
It is tuned specifically for the ZR1 and is not shared with
other Corvette models. The system works with Magnetic
Selective Ride Control to deliver a very competent and
intuitive active handling system – complete with a
Competitive Driving mode.
Michelin
Pilot Sport 2 tires
The ZR1 rides on Michelin Pilot Sport 2 (PS2) tires,
measuring P285/30ZR19 in front and P335/25ZR20 in the rear.
And while the PS2 tire is familiar with enthusiasts, those
on the ZR1 were engineered specifically for the car.
“We didn’t merely specify a set of off-the-shelf PS2s for
the ZR1,” said Juechter. “Michelin’s engineers worked with
GM to develop tires for the car that took into account
factors such as the ZR1’s performance goals, expected
horsepower, curb weight, weight distribution, aerodynamic
downforce, top speed and more. The construction of these
tires is unique to the ZR1.”
To maximize weight savings, there is no spare tire in the
ZR1; the PS2 tires feature Michelin’s ZP technology and can
be driven for a short distance with zero pressure until
servicing can be attained.

Racing-inspired
wheels
The ZR1 rides on
exclusive 20-spoke alloy rims that measure 19 inches by 10
inches in the front and 20 inches by 12 inches in the rear,
making them the largest ever offered on a Corvette. Their
design was inspired by the multi-spoke racing wheels used
on Corvette C6R racecars, which enhance the strength of the
wheel at the rim. A bright, Sterling Silver paint finish is
standard and a chrome version is optional.
The wheels, while slightly larger in mass than the smaller
wheels of the Z06, were developed to be as lightweight as
possible, minimizing the ZR1’s unsprung mass.