Upgrade clutch discs can provide a little better clutch performance, but we would still recommend buying an entire upgrade clutch kit (pressure plate and clutch disc) for total performance.  Sometimes it's just the clutch disc is worn (i.e. pressure plate is in good shape), and a replacement is an economical choice.

Full-faced, organic clutch discs have smoother engagement, and are typically built with Marcel springs (between front and back clutch faces) and a sprung center.  Sintered copper composite linings handle more abusive driving habits.  We have seen clutch discs made out of Kevlar, and these clutch discs have abrupt engagement even with a full face, but Kevlar makes for a very poor material in high heat conditions.  We've heard of Kevlar clutches getting burnt in very harsh racing environments such as drag racing.  We do not recommend getting a Kevlar clutch disc.  Remember, these clutch discs needs an initial break-in to last longer.

Solid center or unsprung clutch discs are stronger (less parts), but they induce a more abrupt engagement.  The springs in the center absorb some of the engagement shock when you engage the clutch.  The Marcel springs in between the two clutch disc faces also goes into smoother engagement.

Those who need a little bit more clamping power, a copper-puck clutch disc is an option.  I've heard a lot of people complain that a copper-puck clutch is not streetable, but I tend to disagree.  The copper-puck clutch does engage more abruptly due to it's copper pucks and non-sprung hub, but I know a lot of people who do street these units.  A copper-puck clutch disc doesn't overheat and fatigue like an organic clutch disc does when abused beyond normal use - like in heavy drag racing.  A copper-puck clutch disc has the advantage of NO break-in period - once the clutch is installed, you can bang away with redline shifts right away!  One word of warning for those trying to street these copper-puck clutch disc:  try not to slip the clutch excessively; the copper-puck disc is not designed to slip a lot - slipping this disc excessively will cause the copper pucks to eat into the flywheel and the pressure plate surfaces.

A recent break-through in clutch technology has been the use of carbon-carbon materials.  Carbon-carbon ("C-C" for short) is not carbon fiber, but a dense carbon matrix that takes high pressure and high heat to create.  The immediate advantage of C-C clutches is the tremoundous heat the material can handle.  Secondary advantages are the fact that the clutch is probably going to outlast the engine/vehicle.  C-C clutches wear very little even under extreme use such as drag racing.  Another advantage is the progressive engagement of the C-C clutch - the C-C clutch grabs stronger as it gets hotter.  Drag racers have been touting their C-C clutches for a few years now.  Due to the softer engagement, there is less stress transmitted to the drivetrain, and drivetrain damage is minimized.  Now, with all these advantages, there has to be a downside - cost.  These things are not cheap!  Kits are made by Exedy and Tilton.

Racing Beat
Exedy Hyper-Carbon Clutch Kits from Cox Import

Questions?  Comments?  Send mail to:  reted@fc3spro.com