RE: Dave, Phil et. al. - some thoughts

[David Eaton <david.eaton@computerland.co.nz>]

but then scott, you turn around and deny that the *same* physics are
acting during your turn with a locked centre diff, and that the effect
is *worse*.

the centre diff puts 50% of torque up for grabs at the axle with the
least traction, while the torsen only puts 30% up for grabs.  so your
trg figures are *worse* for the locked centre...

to use your example "the-wheel-lift-scenario" (i quote):=

"Trg = 300lb/ft car 75/25/25/75.  KISS, look at what that means in
Tshift.

T1 = 225lb/ft
T2 = 75 lb/ft
OR, anywhere in between.
T1 = 75 lb/ft

T2 = 225 lb/ft
Tshift MAX = 150lb/ft"

ok, here we go locked centre generation 1 quattro in the same scenario:-

t1=0
t2=150lb/ft
tshift max = 150lb/ft

or,
t1=150lb/ft
t2=0lb/ft
tshift max = 150lb/ft

so, using the locked centre we have the *same* torque transfer of
150lb/ft.  the only difference is that the torsen has done the right
thing which means when the axle without traction regains it there is not
a sudden instanteous torque transfer of 150lb/ft (using your figures).
with the torsen, this torque modulation is only 75lb/ft which is *half*,
and so should be much more controllable....

so now can you understand why i'm confused at your stance?

dave
'95 rs2
'90 ur-q

>-----Original Message-----
>Date: Tue, 3 Mar 1998 11:04:42 EST
>From: QSHIPQ <QSHIPQ@aol.com>
>Subject: Dave, Phil et. al. - some thoughts
>
>The physics of the torsen dictate there is a huge Torque shift that is
>happening as you turn, given the right (or exactly wrong) circumstances.  It
>appears that is consistent with driving at the limit of available cf, but
>that's not a constant either.  So, please, let's change this from it didn't
>happen therefore there is no spider, to discussing the physics of the torsen.
>Jeff and I have tried to look at the Bite that HAS happened to us, in terms
>of
>the physical limitations of the Torsen.  It has them.  Please, read the
>article, I can easily count those who have been bitten vs those that haven't.
>But those that haven't, have yet to explain what is wrong with the
>explanation
>from those that have.  That is the physics part, not the people part.  I
>don't
>make enemies on purpose, I certainly don't want to make them here, with only
>physics.  
>
>So, I see the pot or the kettle this way.  Either:  A) You accept that some
>have been bitten and some haven't, and accept that by the physics, or B)  I
>haven't been bitten, others that have were driver errror, and the physics of
>the Torsen presented by Jeff, I and others are wrong.  
>
>I personally (with my btdt, and those that haven't btdt) easily accept A).
>IF
>you want me to believe B) I would ask for some specifics.  The homework has
>been done.  Do you accept that the torque shift happens?  My understanding of
>a Torsen center diff is that it is possible, under the right or "wrong"
>circumstances, to shift Torque, a lot of it, from the front diff to the rear
>diff and back again, in the same turn, with rear wheel spin, no lift, and Trg
>is at or near maximum.  And given that interpretation of the Bible (the
>torsen
>paper), I can explain what happen to me, and what hasn't happened to some.
>I
>have a little difficulty looking at physics, and taking the argument that "it
>hasn't happened to me, therefore the physics is not correct".  Please help
>me.
>"I've never been in an accident, therefore all that did had driver error and
>the actuary tables are a farse."  What's the difference here?
>
>Other ideas are certainly welcome.  I don't give a hoot if I'm right or
>wrong.
>If I'm wrong in my interpretation of the physics, please do speak up.
>
>Scott Justusson
>QSHIPQ@aol.com
>
>------------------------------
>
>