Re: How dry I am... (aka AWD perform

[AUDIDUDI@delphi.com]

> in my understanding awd *does* improve cornering speeds, it has to because
> it allows more of the tyres adhesion to be used for cornering because less
> adhesion is needed for *traction* on the driven wheels.

AWD improves cornering -- by definition (mine, at least), this means the max
lateral acceleration a car can generate -- only marginally.  What it DOES do
is improve the transitions between accelerating, braking and cornering ... I
know this may seem like a minor matter of semantics to most people but there
is a key distinction to be made here.  AWD makes a real difference only when
you are trying to put the power down out of a corner or carrying speed under
brakes into a corner ... in other words, it helps you round out the traction
circle by taking full advantage of the car's tractive ability but it doesn't
let you corner any harder than the same car would with just FWD or RWD.
 
> i've seen this demonstrated at an audi driving day where a sharp (wet)
> corner was taken at 100km/hr by a bmw 740i, a jag sovereign, and an s6 -
> all with trailing throttle.  despite repeated attempts, neither the bmw or
> jag would take the corner without spinning (oversteer ie. loss of adhesion
> at the rear due to the driven wheels requiring more of the tyres adhesion
> for traction).  the s6 took the corner comfortably, and would do so until
> about 120m/hr.

This is a red herring since the only "tractive force" a car has to deal with
here (other than lateral acceleration) is a little bit of engine braking ...
and cars with turbos typically have a bit less of this than N-A cars because
they have lower compression ratios.  The differences you observed have to do
with suspension design and/or weight transfer... try this experiment with an
MR-2 sometime and see what happens when you coast through a turn!  Yet, when
it's driven through the same turn under power, it'll run away from the other
cars you mention ... this is the same reason why a racecar will (often) spin
off the track when the driver misses a gear downshifting for a corner.

     _             _             
    / l       l o l  \       l o   Jeffrey Goggin
   /__l l l / l l l  l l l / l l   AudiDudi@delphi.com
  /   l l_l \_l l l__/ l_l \_l l   http://people.delphi.com/AudiDudi