myself running "Stainless Steel" clutch shoes....
something we been trying here at RGX....
so been awhile on the Carbon and Alloy ones....BUT !!
but one thing is for sure with Alloy they will Grab and Lock so you will feel like they have more Punch...too heavy a spring and it will sound like a badly tuned Ready to Run car or truck...
carbon shoes of most kinds will always work...the "Blue Shoes" from CEN work really well with the 1.1 springs...if the track is a little "Slick" the 1.0 springs are really good....
mugen alloy shoes are always a good choice as well...
as with most Clutch set-up's will really depend on the "Stall Rate"
good way to check if your motor is close enough in tune put it up on a stand Block etc......
get it up to "Temp" , hit the throttle for just a sec...let it settle tap the brake to stop the wheels...
if the idle is pretty stable and "Low Enough" the clutch bell should not be "Moving"
if it "Wants to Move" or the wheels are still turning...Either the Idle may be "High"
a "Shoe" might be hanging up...or the spring is worn out....
for a different Senario
if when you get on the track and you hit the throttle and sounds like it hits a high pitch
almot like it wont move then all of a sudden hits....
the "Springs" may be too heavy...and try a "Lighter Spring"....
also make sure the shoes can move "Freely" if the spring is at too high an "Angle"
they will hang up when the engine gets to temp....
hope some of this can help.....