Clutches....

[Iain Mannix <mannix@privateI.com>]

Saw some talk about clutches here recently, the clunk and thump posts, I
believe, so I figured I'd share what I know about clutches.  As far as
Sachs sport clutches, they seem way overpriced.  A friend has one in his
ITB GTI, and his car has a much more authoritative launch than my DSP GTI,
but other than that, I see no reason to get one - at ProSolo events, I am
sure he picks up a tenth or so on the launch - but I believe he paid $500
for it.  None for me.

I am currently using a Sachs 210mm clutch - stock everything with a 16v
pressure plate.  If I overcook the launch, I can sometimes spin the disc
for a second(less than a second, really), but once it hooks up, it is
fine.  No slippage, has 50 or so events on it, plus 20k at least.  No
complaints.  I might try a solid disc - no springs - as I have heard that
they seem to make power transmission more positive.  Don't know.  My car
puts out 117 at the crank, it is driven aggressively, and I have found no
reason whatsoever to use a "Sport" clutch - especially considering the
price.  I believe my Sachs OEM clutch/16v PP cost less than $200, seems
to be wearing fine, and hooks up well - when I do momentarily spin the
disc, which has happened twice, if the clutch had grabbed, the wheels
would have simply spun.  The times the disc has spun were both at sealevel
- my normal launch RPM is 5000/slip the clutch fairly quickly.  At sea
level, I do it at about 4k, as the extra power does make a big difference
- both times, it was at an autocross, first or second run - once at a
Tour, once at Nationals, get a wee bit too aggro, oops, have to lift a
smidge, get it back, go.  It is breif, no smell, barely perceptible.  I
probably launch my car as hard as anyone on the list - it is possible to
be more abusive, IE, sidestepping the clutch, but the way I do it is only
hard on the clutch, it does not shock the engine mounts, CVs, etc - jsut
slip the clutch to get going.  

I've ridden with people who seem to like the thud a dumped clutch makes -
it makes me cringe.  Some people will _dump_ the clutch, shocking
everything, trying to get "rubber" out of the car, be it in first or
shifting to the next gear.  As far as I can tell, _dumping_ the clutch
between gears just stresses stuff and unsettles the car.  Anyhow, that's
what I do, what I want to do, etc - Sport clutches seem pricey for these
cars unless your car is making a LOT of power.  The 16v had 138 stock(136,
something like that), 2.0 that is, and I doubt my car is going to make
more than that, ever - I've also met people with hotrodded 2.0s who still
use the 16v stock stuff without complaint.  IMHO, YMMV, etc, but unless
your car is _really_ making 150+, I don't see the need for something super
expensive, unstreetable, and which does not have the reputation the stock
stuff has - our clutches last 150k easily, if driven right, and the 16v
plate has enough grip for most cars out there.  Best of luck!


I.Mannix(hate to spend money which I don't need to.....)

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