RE: real quattro

["Dave Eaton" <Dave.Eaton@clear.net.nz>]

some examples of similar awd systems to the haldex come to mind:

1) nissan atessa (used in the skyline notably the gtr -aka godzilla) where
100% rwd usually then torque sent to the front axle on slip to a 40% limit.
2) lamborghini ditto.
3) porsche c4
4) the 1997-98 toyota corolla wrc rally car (toyota looked at the haldex,
and ended up delevoping something very similar).

not sure how you can say whether or not the haldex is "an active
differential in terms of performance or advantages".  i personally have yet
to drive one, and when i do next week (s3) will prpbably find it quite
different to it's other implementation (ttq) when i drive that.  afaik, very
few people on the list have actually driven a haldex quattro.

fwiw, in a strictly classical definition the haldex is not active, rather
semi-active, but increasingly levels of computer control/management of the
traction envelope is the future.  it's here already in edl, esp
call-it-whatever.

hth,
dave
'95 rs2
'90 ur-q
'88 mb 2.3-16

ps: for the lister who wanted more technical information, drop me a line,
i've got a haldex white paper scanned...

-----Original Message-----

Date: Wed, 8 Sep 1999 20:19:24 EDT
From: QSHIPQ@aol.com
Subject: RE:  Real quattro

Dave E writes
>yes this is correct - the haldex is basically a "hang-on clutch".
>but in defence of the unit, there are a number of very ruputable
>manufacturers who use very similar technology.  the big advantage of the
>haldex is that it is computer controlled which means that the circumstances
>governing activation, duration of engagement etc are decided by computer,
>rather than my simple mechanics as in a torsen or a vc.

I question "Big Advantage".  Haldex is hardly an "active" differential in
terms of performance or advantages.  Bottom Line:  Computers controlling
differentials can be fooled just as easily as mechanical differentials.   As
a fwd to awd device, "big advantage" seems somewhat of an oxymoron.
Understeer v ?