Contour Enthusiasts Group Archives Forums Modifications Transaxle Clutch for 350-400hp/tq... rate em

I don't think you can get the best of both worlds when you're dealing with torque loads that high AND when the size of the clutch disk is fixed...or limited by the bellhousing size.

The only option I can think of is asking for some company like spec to make a custom clutch setup that uses a pair of stacked clutch disks with a steel intermediate friction plate.
These are out there for high torque Hondas and other cars where there just isn't enough clutch material available in a single disk to hold the torque.
Anyway, with a dual disk design you should be able to use a more normal, softer engaging friction surface with a sprung hub and a pressure plate that would use a little more pedal travel for engagement. One disadvantage would be more mass being turned by the engine that would slow down the engines ability to rev as quick, but it may be negligible since a duratec can be made to reve so quickly anyway. A Fidanze is light enough to offset the change in mass anyway.

The spec3 has very little pedal travel from fully disengaged to fully engaged, making it very sensitive for one. There is a sweetspot though once you start driving it and you get used to it.
The chatter seems to be a bit of a hit and miss though it will always crop up once in a while when taking off from a turn especially when the engine/trans/clutch is good and warm. Some get it worse than others. This last disk of mine was a lot smoother than the first spec stage 3 that I bought and all I did was swap out the disk with a brand new on, same pressure plate.

Anyway, to anwer your question, the spec stage2 is supposed to hold that torque and be quite smooth. I am not convinced that Kevlar clutch disks are [censored], so I would still consider it an option.
The stage1+ would be on the borderline,
And of course we know the stage 3 and greater can hold 400 ft-lbs or more. I know mine has never slipped when I haven't rested my foot on the pedal.