200k95gsr on Nov/29/09 said:
some companies increase the clamping capacity on their pressure plates when you go higher in their "stages" where as other companies like competition clutch uses a different clutch disk with a high coefficient of friction to accomplish the same goals for power capacity (although you can get higher load pressure plates optional with Competition clutches) the advantage to using an almost stock pressure plate with better griping disk is that you do not have excessive pedal effort. thus making the clutch set a more "streetable" setup that lets face it is more popular now since more and more people want a car to do multiple task which is why you see more companies developing "street friendly" high HP/TQ capacity clutch sets
The problem with increasing the gripping power of the clutch disc is two-fold:
1 - increasing the coefficient of friction of the clutch disc is much harder on your flywheel. In addition to this since the friction is greater, the time it takes for your trans and your engine to match revs decreases, adding more shock to your trans. In my experience, clutch 'feel' is greatly reduced.
2 - In higher torque applications, the need for high holding power of the pressure plate is almost essential. Again, we see added stress to not only the disc and the flywheel do to an effect that can be described as 'stop-go', where the disc is subjected to enough torque for it to slip and then instantly bite again because the plate doesn't exert enough force to keep it from losing it's grip. Ultimately, the plate is what sandwiches everything together. You could have a solid metal disc in there, but at the end of the day it's only going to stay put if it's pressed together hard enough.
The goal to a good clutch package is to combine a disc, a plate, and a flywheel that are matched to not only provide adequate holding power for you application, but increase the longevity of eachother without putting undue stress on any one component, including the transaxle.