Re: Torsens in racing

[Dave Eaton <dave.eaton@minedu.govt.nz>]

scott, you are mixing up the difference between the torsen's "bias ratio" and
the static "torque split" of the torsen.

it is quite possible to have a 60:40% static torque split (see the s4, which
has a 56:44 split (or there-abouts).  most audi implementaitons are a 50:50
arrangment.

the bias ratio is quite different and accounts for the relative torque split
which is supported by the particular implementaiton of the torsen.

gleeson's information talks about bias ratios of 6:1 for example, whereas the
audi implementation has a bias ratio of 2.3:1 (ie. a max of 70% of torque to
one shaft, and a minimum of 30% to the other).  the torsen will *never* exceed
this bias ratio, but will operate at the static torque split when equal
traction is availble through both drive-shafts...

btw, one of the major advantages of the torsen in racing is the ability to use
abs.  this factor alone would make the later ur-q's faster than the earlier
(generation 1) ur-quattro's around the circuit...

i think everyone has to accept that audi raced the torsen.  it has appeared in
enough references over a wide enough period of time, and in different racing
series, to give credence to the claim.  of course you san say that it was
bullshit, but quite frankly, why would audi bother?  they front to using vc
diffs, when no road audi has ever had one, so the marketing "damage" has
already been done, ipso facto.  therefore, to accuse audi of selective
mis-representaiton of the facts is clutching at straws.  i would only believe
the conspiracy theory (sorry folks, but that is what it is), if the marketing
information was "sanatised".  admitting to vc diffs, is not sanitised
"marketing speak".  sorry but you're wrong.

in summary, audi used the torsen in racing, along with a number of other
setups.  in the btcc?  who knows.  was the car phil saw representative of the
car used at all circuits?  how do you recognise a racing torsen implementation
anyway?  in the btcc the *absolute* enphasis is on low friction.  why?  because
it is a hp-limited formula (rev-limited actually).  awd gives a significant
penalty in increased drag and weight, before the benefits start to show out. 
they sure as hell are not using the a4 transmisson on those machines...

dave
'95 rs2
'90 ur-q

>------------------------------
>
>Date: Fri, 27 Feb 1998 10:03:57 EST
>From: QSHIPQ <QSHIPQ@aol.com>
>Subject: Torsens in racing
>
>Eliot's comments regarding Torsens in racing make me smile some.  It seems to
>me that both quotations in his posts are from audis input, not from a car
>driven, which is where my quotes differ.  Secondly, I don't find that a 60/40
>torsen to be anything but a 60/40 LSCD.  I suppose you could say it's torsen,
>and I stand corrected, sure isn't the torsen spider we all know lurks in our
>q's nest.  Sure would like to see a test where it was used.  Regardless, we
>can certainly see from those very articles that any reference to a torsen was
>with a 60/40 fixed bias, not the 75/25/75 of the street cars.  
>