Affect of Bad Shocks on Vehicle Dynamics [was Rocking in a turn]

[SMILLER@xxxxxxxxxxxxxx]

Vadim, not that this will answer your question, but I used to own a 1978
El Camino (don't ask why) (OK, ask why - I needed a truck, or something
that vaguely resembled one, and my wife didn't like driving trucks, and
since the El Camino is basically a Malibu with the back of the body
chopped open, this was our compromise).  The front shocks were very
soft (and actually almost new, which is kinda scary).  Driving around a
sweeping turn at speed (OK, in an El Camino 45 MPH in a wide sweeping
turn is "at speed"), the front end would undulate up and down with the
road surface.  This is where I got my first big lesson on the affect of
weight transfer on vehicle balance.  As the front end floated up, the
thing understeered almost to the point of going wide into the oncoming
lane.  Then the suspension would compress downward, putting more
weight on the outside front tire, and the thing would cut a line right for
the inside of the turn.  Then back UP (understeer), then back DOWN
(oversteer), until I got back on straight road again.

We all learn about understeer and oversteer at driver safety schools,
autocrosses and driver schools.  They give us a dose of weight transfer
theory, and then send us out in our Bimmers, with well controlled ride
motions, to do the lab experiments.  Sometimes it takes a while for us to
understand the lesson.  In a lesser car (my old El Camino or your Honda
with worn out shocks) with crappy dynamics at work, the lesson hits
home a lot more quickly.  

Oh, within a week of my first serious El Camino twisty road encounter, I
replaced the "perfectly good" front shocks with Konis that really worked.
 Then it just understeered, which is what will happen to your Honda
when you replace the shocks.  Effects of shock replacement on a
Bimmer (obligatory content) may be less dramatic, but anything that
keeps the dynamics under control and keeps you in your lane would be a
welcome change.

Scott Miller
Golden Gate Chapter
BMW CCA #44977

P.S.  Am I the only one, or do the rest of you put all your automotive
maintenance time into your Bimmers and neglect your 'Merican and
Japanese cars until they start falling apart?

>Date: Mon, 9 Nov 1998 16:51:35 -0800
>From: "Vadim Dubinsky" <dubinsky@domain.elided>
>Subject: Rocking in a turn
[snip]
>... I'm thinking "hey, this is like for real!  I've felt this
>before driving a real car, on a real road."  So now I have a few
>questions about this, some theories and would like to hear your advice
>and thoughts on this.
>
>First of all, what is all that could be causing this?  I suppose a number
>of things -- jerky turn of a wheel, a stab of the gas pedal, uneven
>pavement at the beginning of a turn, etc., but the most likely reason I
>suspect is an exceeded slip angle of my wheels.  I guess my tires are
>loosing traction and slide sideways, but why aren't they sliding in a
>smooth fashion?  Why does it feel like they bite...release...bite...etc?
>
>How can this be avoided in the first place?  Am I simply going too fast in
>the corner and need to slow down before the turn in?
>
>What should I do and should not do once this starts happening?  Should
>I just ride it out without lifting or more steering?  I'm guessing lifting or
>braking would be the worst thing to do in this case.  I don't really know.
>
>Driving on the street this is most pronounced in my '84 Accord, where
>shock absorption is a distant memory (I really need to replace those
>[original 165K mi.] shocks).  I have also experienced this in my '97 M3
>(obligatory content), but not as bad.
>
>Thanks for your thoughts,
>
>Vadim

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