Premature clutch wear. 1st vs. 2nd gen?
synfinatic at gmail.com
Mon Aug 12 09:15:03 PDT 2013
So I've been trying to diagnose why my clutch slips under hard
acceleration. It doesn't slip a lot, just what feels like one revolution
or so. Happens probably 2-4 times a lap at THill depending on how hard I'm
So long story short, I have a nearly brand new (2 race weekends and about 5
track days) 1st gen Barnett clutch pack installed in a 2nd gen motor.
(long story) Although to be honest, the clutch has been slipping for at
least half that time (I've had bigger problems to worry about). I tried
adding more play in the clutch cable last race round, but that didn't help.
The clutch seat & seat spring washers from the 2nd gen clutch are NOT
installed. 4 of the 6 clutch springs were Barnett, the other 2 stock.
I measured the plates. The thicker #2 friction plate is on the high side
of being within spec. Of the remaining 6 frictions, 4 are in spec (barely)
and 2 are just out of spec. All +/- .02mm of spec.
Steels look good, no bluing/etc. Pack was installed correctly per 1st gen
So, seems like I probably need a new set of frictions (I couldn't find any
spec for total clutch pack height, does anyone have any numbers?). What I
don't understand is why the clutch wear was so aggressive. The motor isn't
making crazy horsepower (less then 80HP) and historically my clutches have
no problem lasting more then a full race season.
I know the 1st & 2nd gen SV are *almost* the same... stator, gear position
sensor and oil cooler being the obvious differences on the bottom end, but
maybe there is something different with the clutch basket/etc that would
cause this premature wear?
Right now, the only idea I have is that the clutch cable was too tight and
that caused the premature wear. And by the time I loosened it up it was
too late. But honestly, I never felt any difference after adjusting the
Suggestions or ideas?
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