"Real" Quattro Operation

["Clough, Samuel" <SClough@irps.atl.invesco.com>]

Ok, so I've been following the thread on the new TT's quattro system which,
although I haven't personally driven one, doesn't sound that great to me.
Like others I'd rather see a  system like Porsche's C4 that is primarily RWD
and then AWD.  It would make a much better sports car.  Regardless, being a
little more familiar with the operation of these part time systems, I'd like
to make sure I understand the operation of the quattro system on my 95 A6Q.
I assume it operates the same was as the UrS4/S6 which felt similar when I
drove one.  My assumptions are:
1.  There is a Torsen differential behind the gearbox that determines that
power split front to rear.  I'm assuming it's set some where around 50/50
although I heard that the new S6 is set 45/55 so maybe it's not, I don't
know.  It would make sense to me to send more power to the rear since the
front tires are doing a lot of work, but when did Audi make sense?
2.  This center Torsen differential balances power on torque.  If more
torque is applied to one end of the car rather than the other (I assume some
variability is allowed) then the differential begins feeding power to the
other end to equalize torque (or if it's not 50/50 to bring it back into an
acceptable ratio).  An increase in torque at one end of the car is presumed
to be wheelspin, so by equalizing torque, it's actually feeding power to the
wheels that grip.
3.  Each end of the car offers a similar setup.  I don't know if Audi uses
Torsen differentials at the front and rear of the car or not, but it does
seem to offer some method of equalizing torque/wheelspin because I've
noticed in the A6 if you feed it throttle when the wheels are turned
sharply, you feel a vibration through the steering wheel until you
straighten out which I've assumed to be the front end thinking that the
outside wheel is actually slipping relative to the inside wheel and then
trying to correct the perceived problem.

Am I on target, or way off?

Samuel W. Clough
INVESCO Retirement Plan Services