I've used Dsm Tuners site alot but never registered for the forum. Now I am. Sure sounds like ACT had alot of spring failures for awhile. Some with Slowboy/Kinetic/Competition Clutch too. Spring failures aside, it sounds like the ACT2600 is too stiff in the pedal for my liking and the 2100 too weak for launching, slipping, etc. So no ACT for me. The CFDF actually sounds good with the one caution that you let it cool for 1/2 hour between launches. I'm leaning towards South Bend DXD and Unorthodox racing discs and pressure plates, but the Unorthodox is 50% more. So I guess when cost is an object my choice is between the CFDF and South Bend. Here is the reply from South Bend regarding my inquiry for a light pedal, good daily drivability and heavy launch abuse clutch for 300 lb/ft of wheel torque:
"I recommend using our K 536 SS OFE. This clutch will give you both good streetability and durability at the track. It is a full face clutch and will not groove the flywheel like the puck designs.
Your cost for the clutch with a Fidanza L/W flywheel is $770. If you buy the combo I will cryo for free. "
http://www.dxdracingclutches.com/home.htmlBy the way, I noticed that Shepracing.com has ACT on it's page, so I emailed them regarding the difference between aluminum and steel flywheels and John Sheperd replied: "I feel there is less maintenance with the 1 piece flywheel.
Thanks
John Shepherd"
I guess that means he likes ACT's one piece chromoly flywheel, which has integrated ring gear and pressure plate surface.
Road Race Engineering says on their tech page regarding aluminum flywheels : "... stock flywheel weighs in at about 19 lbs. Our lightened stock ones are 14 to 14.5 lbs. That 5 lbs alone is enough to feel a difference. Aluminum flywheels weigh 9 lbs for DSMs. Now you are talking. You are using less power to spin the flywheel and now have more power available to move your car down the road.
Lots of people freak out about any "theoretical" negative drivability issues with lightened flywheels. They are wrong, it's all good. They are not too light for street use, they won't break apart, they are stepped correctly for ACT and CFDF clutches, On a 80 hp honda you could go too light, but not on anything with enough power to pull the skin off pudding. You will have to compensate a little in your launching technique, a little higher launch rpm will be necessary. Your shifts will be better with the engine rpm now better matching the next gear. These are SFI certified."
Seems like you can find support for any combo if you look hard enough.