i'll let you know once i get my car up and running, but i'm upgrading an Exedy twin plate clutch.
About 2x the clamping force, upgraded intermediate plate release springs (ones that dont snap/break), Carbon/kevlar clutch plates. And it's cheap! I just had to purchase a new top pressure plate as the stock one was far beyond saving (machining flat).

One of my friends is using one, and he's making 420kwatw (new zealand dyno's, prob 600-650whp). It's holding with no problems

 

Care to share the source for these upgraded pieces?

 

www.autoclutch.co.nz

 

Are these parts available stateside?

Regardless, you have part numbers?

 

We had this same exact problem with a buddy of mine's evo. Same clutch and all. It ended up being the TOB clip was partially unseated (crooked) We re seated the TOB clip and all was well after that.

 

i dont have any part numbers.

alot of the work is custom machining etc which i'm sure they wont release for obvious reasons