Re: Alignment problem (?)on an A4 with aftermarket suspension

[DeWitt Harrison <de@aztek-eng.com>]

You've made two big changes at once (bars + springs) which makes
it more difficult to sort out cause and effect. Nonetheless, here is my theory.

It is very probable that the front end became relatively stiffer in roll - due
to either front vs. rear bar rates, or front vs. rear spring rates or both - 
thus amplifying the car's natural tendency toward understeer (plowing). 
When a car is lowered, a great deal of negative camber is automatically
cranked in along with some tow-in, sometimes so much negative
camber that the stock values cannot be restored because of limited
adjustment range. Big negative camber numbers tend to improve the
traction of the front outside tire in a hard turn which reduces
understeer. This is a common track setup adjustment. In fact, it is
common practice to take a cutting torch to the strut towers to
allow use of special camber adjustment plates for even greater negative
camber settings.

Anyway, it so happened that these geometry changes nicely compensated
for the exaggerated front roll stiffness. Then, when you attempted to
restore the stock settings, you lost these compensating effects and the
new excessive front roll stiffness reared it's head. Plow city.

You could restore the large negative camber and have a decent track
setup or you could try reinstalling the stock front sway bar and playing
with the camber setting. Be warned that the high negative camber
plan will eat up your street tires with very little daily driving. In general,
when you start bolting stuff onto your car, you automatically take
on the job of integrating the changes. Your alignment guy can't help
you except to follow your instructions. It could take several trial and
error sessions to get it right. Time to learn how to do your own
alignments?

DeWitt Harrison
Boulder, CO
88 5kcstq

On Tue, 08 Sep 1998 16:19:51 -0700, Jim Simone wrote:
>[ ... ]
>I recently changed the springs and dampers on my '98 A4 1.8T qms. I
>installed the Neuspeed Sport springs and Bilstein Sport shocks; I had
>previously replaced the sway bars with the Neuspeeds, as well.
>
>Anyway, I picked up my car on a Friday from my local shop. They did a
>fine job, and the car felt great. I drive a lot of twisty, mountain
>roads on my daily commute, and it seemed to really improve the handling.
>This made me wonder if I actually needed a subsequent alignment, but I
>followed the general consensus and brought it in to the dealer the
>following Monday.
>
>When I picked it up that evening, I was told that they "couldn't align
>it back to factory spec's" - specifically, that the camber was off. This
>surprised me since I had lowered it only another 10-15mm from the sport
>height - about 35mm front and 30mm rear so that the fenders were all
>even at about 65cm (measured from the ground through the center of the
>wheel). Is this generally the case?
>
>Ironically, now that the car was aligned, it feels less balanced than
>before. The car seems to plow more in hard corners, [ ... ]