[DeTomaso] dual disc clutches

[JDeRyke at aol.com]

Biggest drawback to ANY dual-disc chutch is, the Pantera has very limited 
clutch disengagement distance with its stock hydraulics- typically less than 
0.040". That's 0.020" on both friction sides of a single clutch disc, which 
is not enough to keep from dragging the clutch when shifting gears. With two 
discs, you have 4 friction surfaces so without other changes in your 
Pantera, massive clutch drag should follow, rapidly wearing the ZF synchros. Last 
time I checked, a synchro job at RBT Trannys was around $3000 if you pulled 
your ZF, crated it and sent it in and only one or two gear sets were needed.
Sure, there are things that one can do to increase clutch disengagement 
distances- like an annular throwout bearing such as Tilton (or Quella) sells 
with a slightly oversized clutch master, or adding a significantly larger 
clutch master or smaller slave and putting up with the resulting harder pedal 
(power clutch, anyone?) and others. As someone said, 11"dual-disc diaphragm 
clutches were once used for pumped-up big-block 'Vettes due to their massive 
torque, and I believe Quellas has such a thing available for Panteras. I 
never drove one, nor talked to anyone who has one, though.
Small-diameter multidisc clutches are currently used in sprint cars mainly 
to shrink the clutch housings and lower engine packages while still holding 
high power. Except maybe in the case of some high-buck Mangusta owner that 
wants to gain more ground clearance by chopping the bottom 6" off his 
bellhousing and use a dual 7" dia sprinter clutch setup, I don't see the need in 
our little corner of the sportscar world. I spec'ed this last one out for a 
Goose owner10 years ago and at that time I estimated all the parts and 
adaption at $3500. Good luck- J Deryke