We ask a lot of a clutch. It needs to allow smooth slippage when starting from a dead stop, furnish acceptable pedal effort for all types of drivers, and provide rock-solid clamping under WOT conditions. The factory C6 clutch does an admirable job at all of these tasks and even performs fairly well behind a modified engine. When the stock clutch does reach its limit and the time for replacement arrives, though, the modern Corvette owner has a myriad of choices.
Multi-plate clutches are a popular option because they offer an ideal balance of desirable attributes. For D6C, I chose a twin-disc Exedy Racing unit. A dual-disc setup allows the use of a smaller-diameter clutch, which reduces the assembly's moment of inertia and allows the engine to accelerate and decelerate more freely. The downside? The engine is more likely to bog under a full-sidestep launch, such as at the dragstrip. For you straight-liners, Exedy also offers a line of high-performance single-disc clutches designed with your sort of racing in mind.
Exedy says its dual-disc clutches are "designed for hot street action as well as drag, road, and rally racing." Based on a close examination of the specs, this claim would appear true. All Exedy clutches are immediately identifiable by their brilliant, purple-anodized, billet-aluminum pressure-plate cover. The pressure plate has a 2,500-pound clamp load, and the 8.5-inch friction discs are made of T5001 cerametallic friction materials for extreme heat resistance. This clutch also includes a lightweight chrome-moly steel flywheel that is machined with holes around its circumference for weight savings. If you really want to get carried away with the pound-paring, Exedy offers a triple-disc carbon clutch.
If you have any experience wrenching on your fifth- or sixth-generation Vette, you know that few projects turn out to be as simple as they initially seem. It's no different with the clutch. Unlike with the older cars, the install is not simply a matter of dropping the driveshaft and removing the transmission. No, the C5/C6 requires a serious commitment. You'll need to remove the entire drivetrain from the bottom of the car, starting at the flywheel. (Note: If you are putting a new clutch in a C5, it is recommended that you install a new slave cylinder and throw-out bearing at the same time.)
The following photos give you a good idea of what to expect if you're so bold as to tackle the project yourself. I again relied on LG Motorsports tech Sean Burt, who had the experience and the tools needed to get the job done right and in a reasonable amount of time.
So how does my modified LS2 drive? As expected, the substantial reduction in rotating mass makes it much more eager to rev. The lessened mass will become apparent the first time you stall the engine trying to drive away from a stop. A little more throttle and a lighter touch on the left pedal, and you will be peeling away from stoplights in no time.