For 2001 a Second-Generation Active Handling system, much enhanced over
the original, becomes standard equipment on all Corvettes. Following is
a summary of specific changes:
New Pressure Modulator
The original Bosch 5.0 hydraulic pressure modulator is replaced by an
improved Bosch 5.3 modulator. It is reduced in size, transmits less
noise, and works better at low temperatures. It weighs 3.5 pounds less
than the previous modulator and provides better apply response at lower
temperatures (-20 degrees Celsius), meaning that the system will become
fully functional more quickly after a cold start-up.
The enhanced system has dynamic rear brake proportioning capability,
electronically balancing rear brake pressure to prevent rear brake bias,
or lockup. This new software feature eliminates the need for a rear
brake circuit-proportioning valve, resulting in fewer assembly parts and
fewer brake pipe connections. In addition, the master cylinder pressure
sensor is now integrated into the new Bosch pressure modulator.
Sideslip Angle Rate
Another upgrade for 2001 is the addition of sideslip angle rate control
to Active Handling's core software algorithm. It senses whether the
driver has been too slow (or too fast) to react to changing vehicle
dynamics during evasive handling maneuvers, then dials in just the right
amount of control to help maintain vehicle balance.
Obviously, the rate at which a car tends to slip sideways is magnified
on slippery road surfaces, so more sophisticated calibration algorithms
have been developed to estimate the friction coefficient of the road
surface and modify the second-generation active handling system's
Rear Brake Stability
One more software change results in better rear brake stability control.
It assists the driver in maintaining control under light braking and
high lateral acceleration conditions, such as might be encountered if a
driver is caught off-guard by a decreasing radius turn. This new feature
more precisely releases brake pressure on the inside rear wheel during
high lateral acceleration maneuvers and allows for more predictable
vehicle response so the driver doesn't have to work as hard to keep the
vehicle on its intended path.
Better Coordination with
As noted earlier, Active Handling works in conjunction with the traction
control system, and for 2001 that part of the system has been much
refined. A new control philosophy of targeting specific rear brake
pressures and modulating engine torque around those points has resulted
in fewer engine sags and superior vehicle acceleration when compared to
the 2000 system. This new calibration allows drivers to enthusiastically
experience Corvette's power and handling while still maintaining control
over excessive wheelspin. Average drivers may now elect to leave the
traction control system on when navigating autocross or gymkhana
As alluded to in the previous paragraph, Corvette's Active Handling
system has a unique feature called "Competitive Mode", which
allows the driver to disengage the car's traction control feature
without giving up Active Handling's other benefits. Holding down the
Active Handling button on the center console for five seconds enables
Competitive Mode. This feature recognizes that at the hands of a highly
skilled driver a bit of rear wheelspin may actually be desirable in
autocross or other racing events. In previous years it was necessary to
bring the vehicle to a full stop to enable Competitive Mode, but for
2001 this requirement has been eliminated.
Taken as a whole, the
Corvette's 2001 Second- Generation Active Handling system is smarter,
less intrusive, and more adept at making the total driving experience
precisely what Corvette owners have come to expect from their cars. It
makes the car more agile, allows average drivers to perform better
during spirited driving, and provides a new margin of safety in
Special FE4 Suspension
The Z06 features a suspension system all its own - the FE4 suspension.
It's not available on other Corvette models but is standard equipment on
the Z06. It features a larger front stabilizer bar, a stiffer rear leaf
spring and revised camber settings - all calibrated with a bias toward
maximum control during high-speed operation.
Front stabilizer bar
diameter (hollow): 30 mm with 4.5 mm thick walls
Rear transverse composite spring leaf: 125 N/mm versus 113 N/mm of the
Camber, front and rear: Z06: -0.75º
The Z06's negative camber helps to keep
the tire flatter in relation to the road, and raises the tire contact
patch for greater grip while cornering.
When coupled with other
special Z06 components, the combination above provides unparalleled
racetrack performance ... what the Z06 is all about.
Special Z06 Wheels
Wider wheels and tires increase the amount of contact with the road,
essential to providing better grip. The standard wheels and tires on the
coupes and convertible are quite satisfactory for the majority of
Corvette customers, but for Z06 buyers the Corvette Team wanted more.
Z06 wheels are wider front
and rear than those on the standard Corvette:
17 in x 8.5 in
17 in x 9.5 in
18 in x 9.5 in
18 in x 10.5 in
The new wheels are also one
of the visual identifiers for the Z06, letting onlookers know that this
car is something special. They are uniquely styled, and are the most
mass-efficient aluminum wheels ever produced for Corvette. They are
painted a light gray metallic, and show off the Z06's red brake
calipers, especially when the car is in motion. Each wheel's center cap
has a red Corvette crossed-flags emblem for added identification at
Special Z06 Tires
Goodyear has specifically designed new wider, grippier tires for the
Z06. Called Goodyear Eagle F1 SC (Supercar) tires, they allow the Z06 to
handle, brake and perform better than any production Corvette ever.
Sizewise the new tires
differ from the Goodyear Eagle F1 GS EMT tires on coupes and convertible
Tire Size Comparison
While larger, these tires
are much lighter than the EMT tires, reducing mass by a total of 10.6
kilograms (23.4 pounds).
The new Eagle F1 SC tires
have an asymmetric tread pattern to enable the high cornering
capabilities of the Z06. With the asymmetric pattern the outside
shoulder of the tire performs well in the dry, while the inside tread
performs well in the wet. Testing by Mike Neal, Corvette ride and
handling engineer, proved that the tires make it very easy to drive the
car quickly, have excellent wear attributes, and
make the car more recoverable at its handling limits.
Because these new tires do
not have the "run-flat" capabilities of the EMT tires, it was
necessary to develop a process for dealing with tire punctures, since
Corvettes do not come equipped with a spare tire. In the case of the
Z06, a GM Tire Inflator Kit is included that is capable of sealing
punctures up to 5 mm in diameter.
The kit consists of a
squeeze bottle filled with a non-inflammable latex compound in an
aqueous base, a nozzle that attaches to the tire valve, and a mini-air
compressor with a 12-volt adapter that plugs into the car's accessory
power outlet. The kit functions safely in temperatures ranging from -20o
to 140o F, under wet or dry conditions, and is easy, fast and
clean to use. Similar inflator kits are successfully used by Mercedes
and BMW, and Corvettes sold in Japan have been using this inflator kit
since the introduction of the C5 in 1997.
The latex compound in the
tire inflator kits is not compatible with the tire valves used in
Corvette's standard tire pressure monitoring system, so regular tire
valves are used and that feature is not offered on the Z06. There is a
mass reduction of just over a half-pound as a result.
The Z06's new FE4
suspension, wider wheels, and tires, Second-Generation Active Handling
System and reduced weight allow it to take full advantage of all its
added power. The Z06's agility and "tossability" are truly