RE: torsen tech 201

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

ok orin, we are in agreement.  i thought that you were saying that at the
torque bias ratio (tbr), torque was then diverted from the slower axle to
the faster turning axle.  as i said, that is only true when the torsen is
proportioning torque (i.e. in a "locked state").

with regards to the 0.5 rad/sec, as i said this was specific for a
particular torsen with a 2:1 tbr.  what the locking rate (i.e. the slope of
the curve to the bias ratio using the graph in "torsen tech 103") for the
models used in audi application are, i don't know.  as the audi sae paper
shows, 0.2% forced slip was all that occurred cornering using 5500n of power
in an 80q and a 40m turn (@4m/s/s).  and that was not enough to force the
maximum biasing torque.

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

-----Original Message-----
From: Orin Eman [mailto:orin@WOLFENET.com]
Sent: Sunday, 24 October 1999 20:54
To: Dave.Eaton@clear.net.nz
Cc: Quattromon@cs.com; quattro@audifans.com; orin@WOLFENET.com
Subject: Re: torsen tech 201



> however (and orin makes the same mistake), when the torsen is at the bias
> ratio, *no* further torque biasing occurs.

This is ambiguous.  Who is saying what?
What do you mean by further torque biasing?
At the bias ratio, by definition, the output torques
are proportioned according to the bias ratio.
I never said anything different.  If the torques
are proportioned differently, then you aren't at the
bias ratio.

the diff locks at the bias ratio,
> and *holds* the bias ratio, operating as an open diff.  it can't shift
> torque anywhere other than where ever dictated by tractive force.

It can't see tractive force directly.  All it can see is
relative shaft speed and the torque reactions of the shafts.
Torque reaction as seen by the torsen for a shaft is tractive force _plus_
(moment of inertial of an output shaft * angular acceleration
of that shaft).  I merely applied this pesky acceleration term
which had in the past been ignored.

 as long
> as the output shafts are spinning enough relatively, *all* torque is
> distributed according to the bias ratio.

And that was a very small relative rotation.  Work out 0.5 rad/sec in RPM.

Orin.