I am now testing a new prototype ACT clutch friction disc designed for street/track. I will report back with full details after some more testing, but initial findings are excellent.

 

i have the first and only built just for me, it is a full disc with springs. looks like a stock disk. Dirk(owner of ACT) wanted to build this and test in my car before unleashing to public. i've just driven some street and canyon miles. its streetable, slippable, no chatter, but fairly quick,authoritative take-up. it should be more heat resistant and clamp better. we installed the ACT PP as well, 40% increased clamping. it should be better for the following design: friction material better, supposedly high end material same as Viper and 930, thinner backing cush, stronger plate(Exedy source) and springs. i plan on tracking at sears point with speedventures 4/19, and will be giving Dirk feedback, with then likely to be available as a regular new item from ACT.

it might be nice to test in a stock S2000 as my car is track vehicle with S/C, J's gears, R tires, Mugen LSD, 2550lbs, and Comptech flywheel but i'm pretty sure so far this would not be too much at all for less modded car driven well.

 

Note: DavePK has 50K miles on stock disk with ACT PP!!!!

 

So is it safe to assume that the stock clutch disc is just fine? All it really needs is heavier clamping force?
When you said the new disc is "streetable", can you say that it is still a bit "grabby" for day to day use?

 

Do you have buzzing sound when decelerating ?

 

xv,

yes the stock disc is a good item for OEM part, and yes it would seem that just adding stronger PP largely improves hook-up with smooth engagement. but dave still over heats his clutch on the track but he knows how to recognize that and back off too cool it to preserve longevity and get it back hooking up on track.
for street i would recommend trying this, however this new disc is intended to be streetable, ie smooth engagement, but stronger engagement and heat resistance, also it theoretically decreases the time between engagements due to its thickness charicteristics. remember stronger PP means heavier clutch pedal.