RE: torsen naderism

[audidudi@mindspring.com (Jeffrey J. Goggin)]

>no, phil and myself are not doing that scott.  we're saying it doesn't
>happen on *our* chassis.  open mind on the type 44.  *you* are the one
>saying it happens on *all* chassis.  reality check brother.

If it happens on one chassis -- *any* chassis -- then it must be happening
on ALL chassis.  To what extent it is noticeable (or even detrimental) is
another matter entirely but the Torsen's behavior itself isn't changed --
CAN'T be changed -- just because it's installed in a different car.  How
could it be?

Mind you, I'm NOT suggesting the design parameters can't be optimized for
any given chassis and/or particular set of operating conditions (although,
interestingly, it appears Audi hasn't seen fit to do this) merely that the
Torsen's basic operating principles remain the same regardless of how and/or
where it's used: FWD, RWD or AWD.

For both Scott and myself, this position is non-negotiable yet yours seems
to dance around it.  On occasions, your statements have suggested that you
accept this premise but whenever this is specifically pointed out, it
appears that you back away from it immediately.  Why?    

>scott, you have *never* explained the bite.  you've never set out step
>by step what it is thought to be.  jeff has and, based on jeff's
>description (tight corner with rear oversteer on entry), and
>re-producing the manouever, i have tried to reproduce the bite on both
>my chassis, to no avail.

A minor correction: I don't remember ever suggesting that corner-entry
oversteer and/or a tight corner is a pre-condition for experiencing a Torsen
"bite."  In fact, if you'll recall, I questioned how anyone gets an Audi to
oversteer on corner entry ... given the opportuntity, both of mine
consistently understeer.  If I'm trying, I can usually get them to oversteer
but driving them this way isn't the quick way around the corner hence it's
not something I indulge in frequently.  Sideways driving is definitely fun
but not fast... 

>it says much for your application of the scientific method that you refuse
>to countenance that you may be wrong/mistaken.  you have as much to do with
>scientific study as ralph nader or 20/20 does for that matter.

Actually, Dave, re-read some of your earlier posts ... you might be
surprised by how your position has moved over the past few months.  It
wasn't that long ago that you didn't have a firm grasp on the concept of
"slip angles" and as I'm sure you'll now agree, this is central to any
discussion of the Torsen's performance as a center diff in an AWD
application.  (No flame intended.  Honest.)

>intersting how the ground has moved from 70% effort on a dry road, and
>the bite will happen, to "see you at steamboat".

Big deal ... a low cf surface simply makes it easier to demonstrate the
effect.  I can do it on pavement any time I want -- Yes, I've been
practicing! -- and I'd be happy to demonstrate it to you here in the desert
if you'd prefer.  Seeing that I don't own a winter jacket, I don't have any
plans to go to Steamboat myself!

>fwiw, i *did* play with my ur-q and the wrx's on a nice flat grassy
>field scott.  no bite.  *hell* of a lot of fun.  doing it again in 2
>weeks.  did i spin?  sure.  was it unexpected?  nope.  but hell, those
>wrx's are just using dumb vc's.

Skip the real-world stuff and focus on theory for a bit.  The design of the
Torsen dictates how it operates, period.  It doesn't know whether it's in a
FWD, RWD or AWD car; it doesn't know whether it's in a Type 44 or Ur-Q
chassis; it doesn't know anything about the surface you're driving nor does
it know anything about what the driver is trying/hoping to accomplish or
their driving style.  It's dumb, right?

Given this, my radar lights up when I see words like "anticipate" in a
technical paper ... how does it know?  How could it know?  This statement
goes too far and, in my opinion, smacks of cheerleading, which brings the
impartiality of authors and/or the true purpose of their paper into question.

Why the fixation about what the paper does or doesn't say?  Do you really
think any paper written by Zexel or Gleason before them is going to openly
admit to the Torsen having ANY shortcomings?  Years ago, I wrote a few
technical papers for a company as a freelancer and my instructions clearly
included glossing over the trouble areas, particularly about the fact that
they had compromised reliability in favor of performance by running a few of
the devices well beyond the manufacturer's ratings.  Why should it be any
different for a differential than a mere audio product?

Maybe I'm more cynical than most but I think that until we find a piece
written by an independent third-party -- one who doesn't have an axe to
grind or a marketing person to answer to -- it's unlikely that you will see
any criticism about the Torsen in any technical paper.  Remember, the only
reason these papers are written in the first place is to promote the
manufacturer's products and not necessarily to educate the public at large;
that's generally a secondary goal at best.

>i'm going looking for answers here buddy.  from where i'm sitting,
>you're not.  your usual arrogance notwithstanding.

Alas, the problem with attempting to answer a question that nobody else has
answered is that you can't simply look it up in a book or paper.  In
college, I had a physics course where the tests and quizzes were open-book
and open-note and the prof gave you a "cheat sheet" with every formula you
might need.  And as if that wasn't enough, you didn't have to actually
answer a question in order to get credit so long as everything was set up
correctly ... piece-of-cake, right?

Hardly.  You see, before you could answer the question, you first had to
figure out what it was, which wasn't as easy as it might seem.  If you
misinterpreted the question, then your answer usually ended up being wrong,
however "correct" it might be otherwise.

I sense the same thing is happening here.  We've seen two papers, neither of
which specifically addresses the question we (okay, some of us) want
answered, and therefore we've been forced to extrapolate our answers from
the points they DO address.  Where I went to school, this was most
definitely part of the "scientific method" since they were teaching to teach
us how to THINK and not merely how to regurgitate pat answers from a book.

Personally, I don't discount the value of Scott's input simply because he's
not a published author; likewise, I've spent a lot of time pondering yours
as well and not just so I can figure out ways to refute it.  There's
definitely something going on here, whether you accept it or not, and while
you may find this hard to accept, the truth is that both Scott and myself
will readily (but perhaps not cheerfully) admit to being wrong should
anybody ever be able to conclusively explain to us exactly where we've gone
off course.  Hasn't happened yet, I'm afraid.  :^(

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   / |      _| o    | \       _| o  Jeffrey Goggin
  /__| | | / | | __ |  | | | / | |  audidudi@mindspring.com
 /   | |_| \_| |    |_/  |_| \_| |  http://www.mindspring.com/~audidudi/
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