Re: Spools and ST

[QSHIPQ@aol.com]

In a message dated 98-08-20 12:52:09 EDT, you write:

<< I don't have a problem with the idea of Torsens not being raced in the
 >BTCC - I never thought they were.>>
Totally, absolutely consistent with your posts Mr Payne.   I just figured you
might enjoy the information, you being from accross the pond and all.  If you
don't have the articles I quoted, Iet me know, and I can get you the printed
copies.  Some interesting comments about Thruxton (sp) and Donnington vs. the
A4's (fwd and awd).  
 
> The "spool", though, was described to me (and I described it to the
> incredulity of the list) as a _centre_ option.  I've actually _held_
> the damn thing. >>

Interesting Phil.  The interview with King on this subject is pretty thorough,
and it appears from the following comments, that indeed the spool was
definitely a rear option.  Later in the same interview he speaks that ONLY the
VC was used, with 3 torque splits.  Here is the context of the spool rear and
why:

King - "The spool offered a definite traction advantage and made the rear
tyres equalise their temperature and grip.  We mainly used it on sweeping high
speed circuits that didn't require too much differential action .  It was
quite a hard thing to drive.  You would have thought that it would have given
understeer but the driver could induce a tiny amount of oversteer which took
understeer off the front axle.  It was a technique  that some drivers liked
some didn't.

"The spool actually worked at the tight Knockhill circuit.  You just scoot out
of the corners there - blasting the power down and accelerating out.  The car
was sufficiently balanced that you could flick it through the corners.  At
Thruxton you got away  from the chicanes faster with a spool - but you had to
be very , very careful of high speed oversteer.

A significant amount of oversteer is the last thing any driver wants to have
to cope with on a high speed curve.  King makes it clear that running the
spool at Thruxton was a test of a driver's mettle.  "That's why we needed
brave drivers!  High speed oversteer can unsettle a driver <do I insert "bite"
here:)?>.  Church corner at Thruxton is a good example of that."  

King reports that Audi Sport Uk never changed the charteristics of the
quattro's front and rear VCs but sometimes changed the torque split provided
by the VC centre diff. "We had three torque split (VC) options:  40-60 f/r,
35-65  and 45-55.  The safest was 40-60.If you had too much performance on the
rear axle relative to the front - causing oversteer - you could put the power
to the front.  In practice, we never put power to the rear with the 35-65
option.  Knockhill is a good example where you wanted the car perfrom well on
the nose without oversteer so you could run 45-55.  Faster circuits, it would
be 40% on the front.   "You wouldn't use the spool with a 45 front <biased VC>
that would be too much on the nose.  That would be quite frightening
actually."

Really a very revealing interview regarding U and O in racing.  Especially his
comments about not using the 35-65 option.  Given the torque split on the
street audis can be 22-78, U and O in high speed driving seems like a real
concern.  It's not just me that doesn't like a bunch of oversteer, then a
bunch of understeer.  Maybe the 'bite' phenomenon really has been identified.
Right on UK soil (so to speak).  "Quite frightening" indeed, btdt.

Hope this helps

Scott Justusson
'87 5ktqwRS2
'84 Urq