Re: Differentials

[Eliot Lim <eliot@u.washington.edu>]

On Sun, 29 Jan 1995 PDQSHIP@aol.com wrote:
> Torsen-Gleason by definition is a Torque Sensing Differential... "Automatic
> and variable proportioning between axles," -Torsen-Gleason on quattro
> apps-1992. Throttle-on oversteer as long as the front axles spinning faster
> than the rear in low traction to power conditions (ie snow and/or ice).
> 
> yes?

yes, but your original post referred to the Mk1 quattro with manually
locking differentials which has no such capability when unlocked, no
rear biasing, "hunting" or "sensing".  nada.  it is as dumb as chicken
liver.

the torque split for an unlocked center diff is 50-50 all the way down
to one or more wheels losing grip completely.  if you jack up one
wheel, that wheel will spin and the others will stay stationary, and
the torque split is still 50-50.  in this particular case, the total
torque sent to the front is zero and the total torque sent to the rear
is zero.  see? it's still 50-50.

when you lock the center diff, you alter the split from 50-50 to 100-0
or 0-100 depending on who is slipping.  again use the jacked up
wheel example.  

this is quite different from what you wrote and i'm simply setting
the record straight.  in particular, locking the center diff changes
the torque split from a strict 50-50 to a completely variable one.

my advice for a difficult to control 80Q in snowy/icy conditions is
to get the right tires for the conditions.  i've seen too many
macho 4x4 trucks in the ditch, more so than 2wd cars.  thankfully
i have not seen a quattro yet.


eliot