RE: Diffs, sometimes opinion

["Peter Berrevoets" <peterb@mysysltd.com>]

As one intrigued, amused and entertained by this particular debate, I am
also interested in these "White Papers" and would certainly appreciate
receiving a copy if they could be made available. The URL would also be
fine.

Don't suppose Scott that you have videos of the spin behaviour - it should
be a very pronounced and easily visible progress if one knows what to look
for.  That would make for some very interesting viewing indeed.

I love engineering theory because when applied to the real world it is
almost always replicable.

The one caveat being that for the theory to apply to the real world it must
be able to take into account ALL the applicable data - which is often hard
to obtain accurately - particularly Coefficient of Friction which plays one
of the lead roles in this debate.

Taking that into consideration when designing cars, airplanes and most other
mechanical objects - the design (theory) usually gets turned into a
prototype and tested by a test pilot/driver to see how the design/theory
translates from paper to practice. How many movies are out there with the
designer/engineer/white paper telling the tester/driver/racer that it 'Has
to work" yet it doesn't?

IMWTK

Peter
1990 200TQ


-----Original Message-----
From: owner-quattro@audifans.com [mailto:owner-quattro@audifans.com]On
Behalf Of QSHIPQ@aol.com
Sent: Monday, October 04, 1999 11:04 AM
To: quattro@audifans.com
Subject: RE: Diffs, sometimes opinion


Dave E. gets his hacls up over:
>still ducking and diving scott?

"Ducky" in the rain, and that's driving, Dave.  Should have been at the Road
America National qclub event watching spiders bite torsen cars in the rain.
More spins and offs in a single day, than I've seen in 8years of qclub
events
(not one locker went off, hmmmm)....  Oh yea, the "challenge awaits"

>sort of forgot about the challenge i gave you also?  as it sees to have
>slipped your mind, let me remind you.  tell the list (1) how to experience
>bite (simple steps please), and (2) describe what happens in a 80q (both
>torsen and open centre) accelerating hard in a straight line, and around a
>corner.  slip, weight trasnfer, torque movement etc...sound reasonable?

Most reasonable, in fact.  Dave, in deference to spilling my beer again,
let's take a look at your challenge....   To really look at 1, you could
(simple steps, thank you... Dan) go to the archives new search engine.
Using
it, one could find both the "simple" and the more, er... complex models
(thanks to you directly, dave).  Appreciate your efforts to put it up again,
but Dan has been most lenient on this thread already.  Are you sure we need
*more* archives on this?

When I look at 2...  Agh!  I've just spilt my Fosters.  QSHIPQ ponders:
"Why
would Dave E. pick a couple cars that he doesn't own, and probably never
drove, for comparison purposes".  Hmmmm....  Could it be another infamous
"white paper" perhaps?  :)

A couple things in reference to your recent threads to date come up in that
very "white paper" Dave.  1) reread the "Vehicle Behavior when braking in a
turn".  Why is the torsen described configured at a 75/25/75 split?  Next
question:  If the non abs group B rally cars "ever" ran torsens, do you see
any need for such a high torque split?  Any advantages to having *less*?  If
the weight distribution of the S1's posted by Jouko and Hans are correct,
any
thoughts as to what torsen ratios might be used (if any)?  2)  Look really
hard at the "assumptions" in the section "Vehicle Behavior when Accelerating
in a Turn."  Then reread that section with the "assumptions" in mind.  Any
revelations come about?  I find it amazing that you would pick a "white"
paper to make your stand, that describes exactly the spider bite phenomenon.
Great show Dave.

Now that you've peaked (as apposed to being peaked in waning interest)
everyones interest, maybe you can make that white paper available to the
rest
of the list.  I'm also thinking that you might want to get some more white
paper on the VC differential lock, you stumbled so badly there as well (and
really pimped toyota and yourself, since there *was* a torsen run in the WRC
- uh, that's in the rear of course:).  The torsen white paper you picked to
wipe me with (pun intended:) is pretty complicated for one looking for
"simple" concepts.  To put the 80q v 80q  in perspective, maybe you could
explain what results you'd expect and why, if both cars tested had only a
driver in them, instead of "maximum permissible load".

I'm laughing at myself first, THEN lapse into silence as I wipe up my beer.
Given your "challenge" I could have had a lot more fun, but I'm peaked.
Really dave, you need to get out more...
:)

Scott Justusson
'87 5ktqwRS2 -10vt
'84 RS2URQ -20vt
'87 4Runner turbo