2005 Corvette: Under The Skin: Beneath The Shapely Curves Lies State-Of-The-Art Performance Technology
UNDER THE SKIN: BENEATH CORVETTE C6's SHAPELY CURVES LIES STATE-OF-THE-ART PERFORMANCE TECHNOLOGY
For Release: Jan. 1, 2004, 12:01 a.m.
Source: GM Media Archives
Corvette C6 is the result of lessons learned from C5-R's successes on the track combined with fresh thinking about what a 21st century sports car should be. As the next logical step in the evolution of GM's Performance Cars Architecture, it takes its robust and real-world-validated backbone structure and enhances it with completely new suspension components.
The key features of the backbone structure - low weight, high strength via hydroformed steel frame rails, cored composite floors, enclosed center tunnel, rear-mounted transmission and aluminum cockpit structure - enable C6's top speed, world-class handling, quiet ride and fuel efficiency.
Where the structure has been shortened, it has been strengthened to enhance its crashworthiness. Optimization in key areas - front rails, front bumpers, and hood-hinges - resulted in a design that is more robust yet shorter and lighter than its predecessor.
Enhanced structure, all-new suspension
While the foundation has been enhanced, every suspension component that attaches to it has been changed - none of the suspension bits have been carried over from C5. The short-long arm and transverse leaf spring independent suspension design remains, but the control arms, springs, dampers, bushings, stabilizer bars, and steering gear are completely redesigned. The Extended Mobility Tires (EMT) are also new, taking advantage of the latest compound technology for run-flat capabilities, and play a critical role in the tuning of the suspension for maximum handling and a comfortable ride.
Smoother ride, better handling
Improvements in ride and handling include greater lateral acceleration, more body control, a more relaxing ride, less noise transmitted from the road, and better traction and stability in corners. The specific tuning changes in the chassis and suspension include suspension and steering geometry optimized for better handling and ride, advanced compounds in the tires, new directional control arm bushings, and greater suspension travel achieved through more clearance in the hub knuckles and dampers. The progressive rates of the front and rear composite leaf springs have been tuned to take advantage of the greater travel of the suspension.
The result is a Corvette that is more poised at higher limits of handling.
"It's a much more pleasing ride," says Mike Neal, ride and handling development engineer for the 2005 Corvette. "It's less touchy, it's less tuggy, it's better isolated, it's quieter for road noise. It's all of those things and still a better handling car. Handling is our first priority in the Corvette."
Suspension choices
Three suspension choices allow drivers to choose the setup that best suits their style of driving. Each of the choices (Corvette Standard, Magnetic Selective Ride Control, and Z51 Performance Package) provides outstanding handling, but each also offers drivers the ability to tailor the car's handling traits to specific preferences.
The Standard suspension is tuned for a balance of ride comfort and precise handling. The optional F55 Magnetic Selective Ride Control suspension adds to the Standard suspension magneto-rheological dampers that are able to detect road surfaces and adjust the damping rates to those surfaces almost instantly for optimal ride and body control.
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The optional Z51 Performance Package is a competition-ready system for the true performance enthusiast. It offers more aggressive dampers and springs, larger stabilizer bars, Goodyear Supercar tires with an asymmetrical tread pattern, and larger, cross-drilled brake rotors for outstanding handling performance that is still comfortable for daily driving. Beyond the suspension bits, the Z51 is a total system that takes the "regular" C6 to near-exotic levels of performance. It features gear ratios borrowed from the previous Corvette Z06 for maximum acceleration performance, and includes coolers added for the transmission and power steering systems for aggressive, track-oriented use. The result is a car that very nearly equals the Z06 in track performance - representing a tremendous value.
Next-generation Extended Mobility Tires
The 2005 Corvette takes full advantage of the latest advancements in tire technology, thanks to its long-running partnership with Goodyear. That experience resulted in Extended Mobility Tires that improve both handling capability and ride quality. The tires feature new compounds and sidewall design which permit the tire to absorb impacts yet resist heat generated by zero-pressure use. The new compounds also provide the tremendous grip that Corvette buyers require for top performance. Despite its lower profile, the design of the new sidewall is more compliant over bumps and impacts, which improves ride comfort while reducing noise and isolating the car from road surface imperfections.
Goodyear is supplying two different tires, depending on the suspension package. For the Standard and F55 Magnetic Selective Ride Control suspensions, a standard directional-tread tire is offered for a balance between handling and ride. The Z51 Performance Package - the choice for the serious enthusiast - features an asymmetrical-tread tire that offers maximum handling performance. The wheel and tire sizes are the same for the Z51 option, which will deliver handling abilities similar to the 2004 Z06, despite the slightly narrower width of the new tires.
More robust brakes
With its increased horsepower and top speed, heartier braking is critical to C6's overall balance of performance. The brake systems have been re-engineered from the previous generation Corvette to provide improved durability and excellent performance.
The C6 brake system focuses its improvements chiefly on heat dissipation and durability requisite of the car's upgraded overall performance capability. For the Standard and F55 Magnetic Ride configurations, the brake rotors remain the same diameter as the C5, at 12.8 inches in front and 12.0 inches in the rear. However, the rotors themselves have been thoroughly redesigned. The front rotors weigh 2 pounds more than the C5, aiding durability. They also generate less heat against the brake pads, which improves wear and reduces fade. In all brake applications, the front calipers utilize dual pistons and the rears use single pistons.
The Z51 Performance Package extends the Corvette's braking capability with larger diameter rotors (13.4 inches in front and 13.0 inches in rear) that are cross-drilled.
Dynamic chassis control systems
Three standard dynamic chassis control systems - anti-lock braking, traction control, and Active Handling - operate in concert to provide a strong, but unobtrusive safety net for spirited driving.
"Our philosophy for Active Handling is that it should allow drivers to experience the higher handling limits of C6 without interfering with their enjoyment of the car," explains Dave Hill chief engineer of the Corvette and vehicle line executive for GM Performance Cars. "Our commitment to continuous improvement has resulted in the industry's most sporting stability system available."
The anti-lock braking system detects and intervenes to prevent wheel lockup during braking and features four channels plus a steering sensor. ABS is tied into the Active Handling stability system and shares sensors for steering angle, wheel speed, and acceleration and deceleration in all directions. Traction control initiates individual wheel braking and/or engine torque reduction after sensing excessive wheelspin. Active Handling stability control influences the attitude of the car by applying braking to individual wheels. The optional Magnetic Selective Ride system integrates with these systems to enhance handling and body control by optimizing damping rates based on input from changing road surfaces.
In keeping with Corvette's performance heritage, and unlike more intrusive systems of some competitors, the Corvette Team developed a calibration philosophy based on how Corvette drivers actually drive their cars.
"We felt it was better to calibrate the system around our knowledge of what our customers are going to do, rather than a system that intervenes heavily and slows them down," explains Hill. "Our intent was to encourage Corvette drivers to keep the system on. We wanted our Active Handling System to work with the drivers in their spirited driving, rather than against them."
In all, the C6's dynamic chassis control systems are smarter, less intrusive, and more adept at making the total driving experience precisely what Corvette owners have come to expect from their car.