[s-cars] Body roll with new tires

[Trevor Frank]

Tim I think that there could be two things at work here.  1 is that
these tires have more stick.  The other and most certainly is that at
stock spec's compared to the 1.5 deg negative you are getting more roll
onto the side wall.  As the car corners and rolls you lose camber, the
1.5 compensates for this a bit and keeps the tire flatter through a
turn.  With less camber you can get into a situation where you are
running on the sidewalls.  Driving style, spring rate, ride height,
sidewall stiffness all play a role in this, as well as other things I am
sure.

For instance I run 1.9 deg neg in the front and 1.6 in the rear.  With
255x35x18's with reasonable success on the street, 400lb springs front
and rear, fairly even tire ware.  On the track though this is a very bad
set up where you are turning more aggressively, there I will run around
2.5 in the front and 1.9 in the rear.  This is all also susceptible to
different suspension set ups.  Generically with heavier springs you need
less camber, with stickier tires you need more camber.

-----Original Message-----
From: s-car-list-bounces at audifans.com
[mailto:s-car-list-bounces at audifans.com] On Behalf Of tlarson at tds.net
Sent: Tuesday, June 29, 2004 7:21 AM
To: s-car-list at audifans.com
Subject: [s-cars] Body roll with new tires

I just put new Pirelli P Zero Nero's on my 92 S4 today, and when I got
it back, the car seemed to roll a lot more than it used to.  With the
previous tires (Fulda Extremo's), there was almost no body roll at all.
Does anyone have any experience with the Pirelli's maybe haven a softer
sidewall?  I also got my car aligned at the same time.  Beforehand, it
was 1.5 degrees on both sides.  It is now back into spec.  Could this be
the cause of the body roll?  It feels as if the car is going to
oversteer, and a few times even required countersteering.  Any help is
appreciated, Thanks!

Tim Larson


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