Generation 5 (C5) – 1997-2004
The introduction of the C5 generation represented one of the rare instances in the automotive world when a new model weighed less than its predecessor. The 1997 Corvette was larger overall than the outgoing C4 yet weighed nearly 100 pounds less.
A number of contributors helped drive down the C5’s curb weight, including the use of SMC body panels that had a higher content of plastic than ever before. The C5’s panels were exceptionally light, but so was the Corvette’s all-new chassis, which used beefy rails and hydroformed sections to provide strength with less complexity and weight. The floor sections used a sandwich of materials including featherweight balsa wood to minimize mass.
An all-new Gen 3 small-block also contributed to the C5’s weight savings and overall greater balance. It featured a lightweight aluminum cylinder block and aluminum heads, as well as a composite intake manifold that weighed less than 10 pounds.
When it came to manufacturing, Corvette led with the changeover to a more environmentally friendly waterborne paint system that reduced solvents in the mix from about 60 percent to about 10 percent. Today, waterborne paint systems are the standard for nearly every auto manufacturer.
Generation 6 (C6) – 2005-13
The sixth-generation Corvette raised eyebrows because it didn’t raise its headlamps. For the first time since the 1962, the Corvette featured fixed headlamps, a move to reduce weight, complexity and aerodynamic drag. The dual-round taillamps and cockpit-style interior remained.
The C6 Corvette shared the basic chassis layout and architectural design as the C5 and despite additional safety features that added a few pounds, weight reduction initiatives – including the fixed headlamps – kept the car’s curb weight within about 20 pounds of the 1997 model.
The 2006 introduction of the C6 Z06, however, represented a commitment by Chevrolet to the Corvette’s performance through technology and lightweight materials. It featured an aluminum-based chassis structure in place of the standard model’s steel structure and carbon fiber body panels that contributed to a curb weight of less than 3,200 pounds.
Despite looking like the steel chassis of the base Corvette, the Z06’s aluminum frame weighed nearly one-third less. And besides the core material difference, the aluminum frame features a unique manufacturing process that incorporated metal inert gas and laser welding, as well as self-piercing rivets. Magnesium is used for the engine cradle and some other suspension attachment points, for greater mass reduction. On the outside, the Z06 differed from base Corvettes with carbon fiber panels used for the front fenders, front wheel houses and rear fenders. The 2009 Corvette ZR1 used the same aluminum chassis structure as the Z06 and incorporated more carbon fiber body parts, including the roof panel.
The lightweight materials and advanced technologies that drove the development and performance of the Z06 and ZR1 set the stage for the seventh-generation Corvette, which will feature an aluminum frame structure on the base model that is about 60 percent stiffer than the Z06/ZR1 frame. The C7 Corvette also builds on the powertrain technology pioneered with previous models to help make it the most powerful standard Corvette ever and the most efficient.
[Source: General Motors]