Re: Physics is....

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

>From:	QSHIPQ [SMTP:QSHIPQ@aol.com]
>Sent:	Tuesday, March 10, 1998 6:31 AM
>To:	David Eaton
>
>
>>scott, when the (rear for example) is slipping as you describe, then it
>>is describing an arc (by definition).  this is a pretty radical
>>cornering attitude, by definiton (aka handbrake turn)...
>
>No, a handbrake can be applied with NO change in arc, so I don't go there
>with
>you.  The question is, in terms of an absolute traction world, is applying
>the
>handbrake going to shift torque.  I argue yes, regardless of slip angle.

i should hope so!

>Remember, 'radical' doesn't have to be.  'Radical', by your own definition is
>LESS than a wheel lift.  You must understand the argument you are making.  If
>no wheel lift is 'radical', what is wheel lift, 'more radical'?  By
>definition.

i mean that radical is any corner where the amount of slippage which you
describe is occuring.  wheel lift when i do it, is not as radical as when
traction has gone and the car is slipping sidewards.  thats almost rallying
dude, and you need a bit of run-off for that imho

>
>>another thing which i've gone on about is that the torsen is responsible
>>in the ur-q for a major change in the balance of the car in the 'mb' and
>>'rr' models, towards one which is much more neutral in it's balance.
>>this is, as you descibe, because of the fact that in 'normal' cornering,
>>the torque is biased towards the rear, due to the slip angle thing
>>happening at the front.  
>NOT necessarily.  Remember a normal corner, center torsen allows for some
>slip
>between f & r.  By the definition of the center torsen, 'significant' is
>defined as any more than 22% torque/speed differential.  So 'normal'
>cornering
>may not be affected.

this is not my point.  my point is that the 'mb' and 'rr' understeer *less*
than the 'wr'.  fact.  reference any road test of the cars.  why?

1) the suspension geometry (as evidenced by the setup data) did not change
(although the wishbones did on the 20v).
2) springs and dampers did not change afaik.

the only thing which stands out here is the torsen.  you describe t(shift)
under cornering, jeff agrees and says that t(shift) to the rear occurs under
normal cornering with the torsen.  so maybe this is what decreases the
understeer in the torsen ur-quattro's.

time for some more data on this.  time to experiment in a controlled
environment...

dave
'95 rs2
'90 ur-q