Short story: I ran this clutch & aluminum flywheel assembly for 10k miles on the street and 1 dyno visit, where it came apart :p Great clutch! Putting down nearly 400 lbs/ft to the wheels, this clutch never slipped. Engagement is tight, pedal is heavy, but if you are looking at twin disc units then this is not an issue.
The reason it came apart is when I installed it, I monkeyed one of the flexplate-to-flywheel bolt holes in the parent aluminum. I drilled out all four, installed TimeSert bushings for oversize hardware, and went from there. According to ClutchMasters my modifications created an out-of-balance flywheel which resulted in the subsequent damage.
I sent it back to ClutchMasters for an inspection, and for $800 (plus shipping) they will rebuild the unit to new specifications, installing a new aluminum non modular flywheel, 2 new friction discs, and a new center floater plate. The only thing being reused is the pressure plate. They have modified the twin disc setup as the setup I had was a modular kit, the new kits they sell are non-modular so this kit will receive the revised design.
$800 for a $1600 MSRP Clutch & AL Flywheel Assembly
ClutchMasters currently has the unit, and is waiting for the go-ahead to rebuild it. I am not making any money on the sale, by agreeing to buy this, you are paying for the rebuild - I have already eaten the cost of this clutch when I bought it.
