Since our project LS2 GTO currently sports Nitrous Express nitrous oxide injection, a whole bunch of bolt-ons, and sticky Nitto NT-555Rs, we've decided to proactively ditch the factory GM clutch before any problems arise. With a heads and cam swap on the way and more juice to follow, clutch slippage would be inevitable, so we need a clutch to match our needs to come.
For this application we chose RAM's Powergrip clutch set. Carrying PN 98931, it retails for $448. It's advertised as being the ultimate clutch for "extreme street/strip performance" and nitrous use, which fit our needs to a T. It's the midrange offering from RAM, with the Powergrip HD and VDS systems being higher-capacity upgrades. Though RAM does not give its clutches a torque capacity rating like other companies do--RAM feels these numbers can be misleading since many factors about a given vehicle affect the clutch's ability to hold--RAM did tell us that "real world" numbers on a properly geared car are around 550 rwhp with this clutch.
After the RAM clutch was installed, we found pedal feel was quite firm, more so than the S.P.E.C. unit on our LS1 F-body. This is thanks primarily to the RAM's 2,800-pound pressure plate, which RAM says is a full 250 pounds more than competing brands; the factory hydraulics are said to be more than up to the task of handling the additional pressure. Also, we initially found that the clutch pedal on the GTO had to be pushed all the way to the floor to fully disengage, which made speed shifting a bit more challenging. Upon inquiry, RAM said the clutch engagement point would rise as the clutch wore in, and after several more miles, it appears that is the case.
There is definitely more pedal effort required with the RAM clutch as compared to the stocker, but it's not excessive by any means. We also discovered that the RAM presented little chatter upon engagement, likely thanks to RAM's hybrid design of 300 series (organic) and 900 series (metallic) materials. RAM says it doesn't play up this fact too much though, and "it's more about a balance of static pressures and friction materials that provide a reliable, driveable combo." Now that our drivetrain is fully beefed, we'll be throwing some serious power at it in the form of an AFR/Speed Inc. heads/cam package with a shot of juice on top. Things are starting to heat up with our '05 Goat--stay tuned!