Recently, we were invited to attend an early preview of the '08 Corvette, staged during the 10th Annual C5/C6 Registry Birthday Bash. The Bash was held at the National Corvette Museum, just across the street from the Bowling Green Corvette assembly plant. Our preview included a one-hour drive in a six-speed automatic coupe with Vehicle Line Executive Tom Wallace. Wallace briefed us on the car's many changes during our spirited romp through the Kentucky countryside. Later, we drove a black manual-trans coupe accompanied by Mark Gardner, an industrial engineer at the Corvette plant.
Aside from a variety of new wheel designs, our first walk around the new car offered no obvious clues as to the extent of the changes for '08. On the road, however, the first thing we noticed was the improved throttle response from the larger, 6.2-liter (376ci) LS3 engine. This engine produces 430 horsepower at 5,900 rpm and 424 lb-ft of torque at 4,600 rpm in base trim.
The car we drove was also equipped with the optional NPP dual-mode exhaust, which adds 6 hp and 4 lb-ft to that total. It retains the 2.5-inch pipes from the '07 model, but includes new, vacuum-operated mufflers similar to the ones on the Z06. At wide-open throttle, the two inboard pipes open. The system makes a robust, throaty sound under power but remains quiet during normal driving.
The six-speed automatic provided very crisp shifts compared with the last '07 we drove. According to Wallace, the transmission has been improved with new hardware and controller calibrations that deliver quicker responses. This translates into 30 percent faster upshifts and 50 to 75 percent faster downshifts. Wallace also told us the car we were driving had the new-for-'08 2.73 performance axle ratio. This ratio will be available on all automatic cars (a 2.56 axle is standard) and included on automatics equipped with the Z51 package.
We noticed a much more direct feel in the steering as we pitched the car through tight corners. Wallace divulged that the rack-and-pinion system was revised to provide improved feel at all speeds. The revisions include premium machining of the system's internal components and a new, stiffer intermediate shaft with controller-calibration changes. The changes made us feel more in touch with the car during our aggressive drive.
Our car was also equipped with the optional Magnetic Selective Ride Control. The option has a new rotary selection switch on the center console that made changing the suspensions settings from Touring to Sport easier while driving. Larger cross-drilled brake rotors are included when this option is selected. Overall, we were very impressed with the improvements that have been made to the automatic-equipped Corvette.
Next, we moved into a black six-speed manual coupe. Gardner told us the car was equipped with the new TR-6060 transmission. This trans will be installed in all base and Z06 Corvettes for '08. It features reduced shift effort and travel. We noticed the difference immediately. Unlike previous manual C6s we have driven, this car shifted very positively and with very little effort. We especially liked how easy it was to shift from Second to Third gear. We did not feel any vibration through the shifter, and Reverse was always easy to engage. People may not be so quick to change to an aftermarket shifter once they've experienced this new, improved transmission.
The final big news we uncovered during our preview was the availability of an optional leather-wrapped interior package. This interior is hand-fabricated by Draxlmaier Corporation in Duncan, South Carolina, and will be available on all coupe, convertible, and Z06 models. Details include the following:
* Two-tone, leather-wrapped upper and lower instrument panel, door pads, and seats
* Choice of two new, exclusive colors-Linen and Sienna
* Padded door-panel armrests
* "Corvette" embroidered on passenger-side dash pad
* Embroidered crossed-flags logo on headrests
* Unique center-trim plate with a carbon-fiber-style pattern
This new interior lends some much-needed aesthetic polish to the C6's cabin. After all, many of the cars that compete in the Corvette's segment are available with similar upgrades; it's about time the Vette countered with a dress-up package of its own. No pricing for this option was announced.
The black coupe we drove was equipped with the standard '08 interior, which features a new instrument-panel center-trim plate and bright surrounds for the shifter and cupholder. It's also equipped with new, metal-finish doorsill plates as well as a lighted control knob for the available Magnetic Selective Ride Control. All Corvette models now come standard with the following:
* OnStar with available Turn-By-Turn Navigation
* XM Satellite Radio
* Auto-dimming rearview mirrors with compass
* Audio-input jack on all stereo systems (except navigation)
* Personal Audio Link available as a dealer-installed item with navigation system
Though subtle, the changes for '08 add up to a much more enjoyable driving experience. As the C6 enters into its fourth year of production, we think new and returning buyers will continue to be very happy with the look and feel of America's favorite sports car.
As we mentioned in our main story, the new LS3 is rated at 430 horsepower and 424 lb-ft of torque with the standard exhaust system. This increases to 436 horses and 428 lb-ft with the optional exhaust.
To achieve those numbers, the engine features a larger-bore block (4.06 inches vs. the LS2's 4.00 inches); high-flow, LS7/L92-style heads; larger-diameter pistons; hotter camshaft timing; a revised valvetrain with offset intake rocker arms; a high-flow intake manifold; and the larger fuel injectors from the LS7.
In addition to its larger bores, which help create a 376ci displacement,the block casting also features revisions and machining in the bulkheads that enhance strength and improve bay-to-bay breathing. New pistons are designed to suit the LS3's high-rpm performance capability.
The new heads use straighter, larger-capacity intake ports to optimize flow to the combustion chamber. The exhaust ports are also designed for enhanced flow. Complementing the enlarged ports are upsized valves. The intake valves increase in diameter from 2.00 inches to 2.16 inches. They feature lightweight hollow stems, which contribute to the engine's 6,600-rpm capability. The exhaust valves are also bigger, measuring 1.60 inches versus the LS2's 1.55-inch units.
To accommodate these large valves and enable more-direct intake-port flow, the intake-side rocker arms are offset 6mm between the valve tip and pushrod. Actuating the valves is a new camshaft, with intake-side lobes providing more than a five percent increase in lift (now 0.551 inch). Exhaust-valve lift remains unchanged from the LS2.
Ensuring the cylinder heads receive all the air they can handle falls to a new, acoustically tuned intake manifold. The composite design is manufactured with a "lost core" process that minimizes runner-to-runner variation and reduces airflow losses. An acoustic-foam material is used to reduce radiated engine noise; it is sandwiched between the outer top of the manifold and an additional "skull cap" acoustic shell. Also, engine covers feature a noise-reducing insert to provide a more refined engine sound.
Chevy personnel provided Team VETTE with the following performance data:
|* 0-60||4.1 (manual) / 4.3 (automatic)|
|* Quarter-Mile||12.4 at 117 (manual)|
|* Top Speed||190 mph|
|* Skidpad||92g (base) / 98g (Z51)|
|* Nrburgring Lap Time||7:56 (Z51)|
The LS3 makes the six-speed, paddle-shifted C6 the fastest automatic-equipped Corvette ever. The LS3 manual, meanwhile, is faster than a C5 Z06. Now that's what we call progress.