After 40,000 miles of driving, we finally annihilated our 2001 WS-6's stock clutch with the addition of a ZEX direct port nitrous system. A bunch of trailer towing and some poorly executed burnouts and track launches surely contributed to its downfall, and it was shot to the point that a full-throttle shift would set it slipping.
Thus arose the perfect opportunity to test one of SPEC's clutch kits. This Alabama-based company has had so much success in the late-model GM community that its products have become the benchmark to which other clutches are compared. Although SPEC was just about to release a brand new Stage 3 Plus kit, deadlines forced us to choose the regular Stage 3 system for this installation. Like the Plus, the standard Stage 3 kit is designed with heavily modified street and race engines in mind, but has a somewhat lower torque capacity.
And this kit has turned out beautifully. Though some initial clutch chatter was present during the first couple hundred miles of driving, it has since subsided to the point where the driver must make a bad start to notice anything but a very smooth, progressive clutch engagement. In our experience, this happens at the rate of only a few times a day. Pedal feel is only slightly heavier than stock, and-get this-overall driveability is actually better than from the factory. Thanks to this clutch system's careful design and manufacturing, shifts can be executed more smoothly, and the car's Pro-5.0 shifter glides through its motions more easily than before. According to SPEC, "the reason for the easy shifts is a cleaner and quicker release, which is achieved through very tight machining tolerances on the flywheel, disc, and pressure plate and a higher rate of lift of the pressure plate. Another component would be the no marcel gap disc, which separates itself from the friction surfaces quicker." Twelve-second timeslips at 117 mph can now be attained without worry in this 425-rwhp 'Bird, and though we've yet to slap any kind of sticky tires on this vehicle, we're certain the SPEC clutch would have more than enough capacity to handle some very hard launches-and do a real number on the Trans Am's stock rear axle.
As you follow through our installation, try to contain your jealousy that the author possesses a 9,000-lb automotive lift in his home garage.
Good to 680 lb-ft of torque...
Good to 680 lb-ft of torque and carrying PN SC093, the Stage 3 clutch kit from SPEC fits all 1998-2002 LS1-powered F-bodies and retails for $449. Included are a pressure plate, clutch disc, clutch alignment tool, throwout ("release") bearing, and slave cylinder spacer. SPEC says their Stage 3 Plus kit is better in every way (driveability included), but you'll have to pull another $149 out of your bank account to enjoy its 850lb-ft capacity.
In lieu of resurfacing the...
In lieu of resurfacing the stock flywheel, we chose to go with one of SPEC's steel flywheels, PN SC75S ($249). An aluminum version is also available, but its reduced mass will hurt street driveability as well as dragstrip performance. Go with the steel, unless you're a hardcore road racer, and save the $150.