Re: torsens

["David G. Lawson" <dbldmnd@compuserve.com>]

>
>if you put one axle on a dolly, the locked center diff will redistribute
>torque 100/0 to the axle that is not on the dolly.

nope eliot is quite right, just one wheel off the ground will stop the
drive to
that [virtual] axle (generation 1 locked centre diff, generation 2 torsen),
and
to the whole car (generation 1 open centre diff, not so with the torsen).
<
Actually, with the locked Gen I center diff and 1 wheel not contacting the
ground, the power(torque) split between the front/rear axle is still
50%/50%, it is just that the 50% going to the axle with the wheel off the
ground is wasted turning that wheel. So only 50% (not 100%) of the power is
transmitted to the axle with both wheels touching the ground.

A few years ago we once did an experiment when the center diveshaft was out
of an 83 ur-q, gen I system. With no differentials locked, we tried driving
the car and all the power was transmitted to the center driveshaft flange
and the car went stood still. All the power was transmitted to the
(virtual) rear axle because the center diff thought a wheel was spinning
and directed engine power back there. This was a true test which shows that
w/o the center locked, it only takes 1 spinning wheel to stop the progress
of a quattro. This is why people almost always lock the center diff at the
ice track in steamboat, in the locked position it takes a spinning wheel on
each axle to loose traction.

I will also throw in another, center diff locking example. This past may at
the stapleton q club event, a nice storm blew in at the end of sunday.
During the last session many people were packing up, so qshipq and I were
out in my ur-q getting some good learning(for me) laps in. The track is
setup on the stapleton airport runways and turn 2 is an 80 degree right
hander which crosses a start of a runway(think of big painted stripes) with
a real big crown in the center. The storm brought a good rain at the north
end of the track where turn 2 is  and the south end was dry. Anyways we
exit turn 2 and accelerate over this crowned runway and unweight the car,
then the car weights down (no locked diffs here), oh boy did that 1
spinning wheel want to spin. An interesting moment, indeed. Shortly after
that, qshipq locked up the center, and over the same section the stability
of the car returned (no back end wanting to come around).  

This is a great techno discussion thread, keep it going.
-
Dave Lawson, avid CenterDiff locker when running fast and deep 
90 200 TQwagon, with rear diff disable disable switch
83 ur-q, gen 1, where did I put those extra electro/vacum servos