[s-cars] New tires, shocks, and the occasional bump in the road - er, wallet

[Steve Voit]

S-heads:

Since the beginning of time I have run Eibach sport springs, Bilstein Sport
shocks, and (225/60x16)Michelin XGT4, then Pilot Sport A/S, then Pilot Sport
A/S+ (2 sets) over the years.  I found 2  things to be true:  (1) The
Michelin tires looked less and less beefy/cool over successive generations
but their performance always improved, and (2) the Bilstein shocks always
started way to stiff, were great for ~20k miles, then were too loose
thereafter.  After the last set of Michelin A/S+ uncharacteristically
disappointed me (chunking tread blocks breaking off, strange noise) and
having 2 sets of short lived Bilstein shocks in the garage I decided it was
time for a new approach.

I mounted Koni sport adjustable shocks and Bridgestone Potenza RE970 AS
($134) pole position tires.  The AS970s are highly regarded on Tire Rack.
The car was smooth & quiet with good adhesion at the limit.  Dynamically not
so sure – not nearly as confident mid-turn, and seemingly overwhelmed by
simultaneous braking/turning, especially on rough surfaces.  5k miles later
I couldn’t take it:  I concluded that the tires just did not have a stiff
enough sidewall to match the spring rate and weight of the car AND the Konis
at ½ of setting were under damped.  Sigh.

Last week I had the shocks adjusted to ¾ setting and I mounted up another
new set of tires -  the new Michelin A/S 3.  This set-up is sublime.  Most
surprising is the contrast comparing 2 new tire packages, which one rarely
gets to do:  Compared to the 970AS the Michelins jump into turns, they feel
energetic and confident, they are stable in sweeping high speed turns.  They
are quiet.  I’m totally satisfied.  The ¾  Koni setting is right for the
Eibach springs, too, hope they hold this damping for a long time.  Only
downside is a tendency to tramline in rutted freeway lanes – which I can
easily live with.  The new setup rides a bit harder, but very reasonably so,
and to be expected.  Oh, they don’t fill the wheel wells and look as cool –
the bridgestones looked cool.

In the end I want to endorse the Pilot AS3 tire ($141) and point out how
important it is to have a sidewall stiffness to match spring rate stiffness,
particularly on a heavy car like ours.

Because you’ll ask:

a)      I sold the 970 AS to a used tire store for $55 ea. b) I have 1 or 2
low mileage ‘worn’ sets of Bilsteins to sell – make offer; c) I have a new
set of +10%/+30% factory customized Bilsteins (happersized, too stiff for
me) to sell – make offer, d) also original headlight assemblies (perfect
shape), orig springs

Steve Voit

95.5 S6 Seattle

140k miles