Re: Marketing 101

["James M. Simone" <jmsimone@ix.netcom.com>]

QSHIPQ wrote:

> Maybe the idea that in a straight line, the torsen wins.  Darn
> turns.  The biggest issue against the torsen is predictability (and you can do
> an archive thread, or post me privately for the book version).  It assumes all
> inputs to the device to be traction inputs.  Even when they aren't (slip angle
> f&r and relative f&r slip angles) traction inputs.

So, do the Audi safety geeks (and their law department) just hope that you don't
ever approach those limits, or do they assume all roads are straight as an arrow?
;-)

> AND, ABS works (this is in deference to the old lockers, which disabled the
> abs).  To jump and say that ABS works 'better' in a torsen than in a VC needs
> a lot more data than has been published.  Given Trg at a minimum, I don't
> think either claims a win, both are 'linked' to some extent (in techno terms,
> both have a decel Bias Ratio).  Racing, the Torsen was not used to any great
> extent (singular exceptions so noted) in the audis.

Since it's been "proven" that ABS actually causes accidents, though, that's not a
issue. Right? <smirk>

> What the torsen EXACTLY lacks, that a VC doesn't, is that you can get U-O-U
> (understeer = u, oversteer = o) in the same turn with no 'traction' reasons
> for Tshift.  A torsen audi then exactly doesn't maintain chassis character
> thru a turn, since at 50/50 static distribution it understeers, at 78r/22f it
> oversteers, and at 22r/78f it understeers.  A VC (3kgtVr4 for instance) has a
> primary set of drive wheels, and the lock is at a specific ratio, that can be
> made to keep the inherent chassis dynamics, here O-O-O.  Even with slip angle
> variables, the chassis dynamics doesn't change, it's still oversteer.  Just as
> predictable as a locked 50/50 audi diff at U-U-U, only better (racers tend to
> use a 65r/35f split as preferred, btw).

At what speed does this O-U-O chassis change really become a problem? Is this more
apparent on the track?

> The argument FOR torsens is in terms of absolute traction devices.  In a
> straight line, they can't be beat.  Darn turns.  Good marketing, and the
> beaners were happy to.  A torsen center, with open front and rear is cheaper
> than a locker and all it's hardware.  The customer is happy, cuz 'ABS OFF'
> doesn't appear when they fear in need of it the most in a locker.  Sounds like
> a win win.  Yup, until you go to steamboat, or drive with Jeff and me at a
> track, or step out a little in the rain or snow.  Then spiders land in your
> lap.  An absolute traction device fooled, has some (upside-)downsides
> associated with it, when turning.
>

 So, are you telling me I should have bought the FWD A4 instead???

> Not a single other manufacturer uses torsen centers.  I argue for good reason.
> And believe the audi racers knew it too.  Too bad they didn't take those
> marketing boys for a ride.....
>

Again, please excuse my ignorance a little longer, but which AWD system then was
the Audi team using before it was recently disallowed?

Do you think Audi AG will ever develop Quattro version #? that will address these
shortcomings?

Thanks again,
Jim

PS: Feel free to mail me the "book version" privately. I think I'm actually
starting to understand some of this stuff.