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Re: [evolution-disc.] e36 bmw suspension tuning question

To: Mark Andy <mark@sccaprepared.com>,
Subject: Re: [evolution-disc.] e36 bmw suspension tuning question
From: Dick Rasmussen <rasmussend@mindspring.com>
Date: Mon, 02 Aug 2004 12:05:57 -0400
At 11:09 AM 8/2/2004, Mark Andy wrote:

>Overall the car has one major issue that gives me a ton of trouble.
>Initial turn in feel and response (say, the first 10' to 20' into the
>corner) is almost non-existant.  One time you turn the wheel and the car
>sorta tries to initiate the turn.  Another time and the car just plows.

Mark,

I'm assuming that you have determined that none of the famous BMW bushings 
and mounting points are worn out or broken and that the hubs, etc. are ok 
and nothing is loose. Also, I assume that any "rubber" in the steering 
system (rack mounting or steering shaft) is healthy and not deflecting 
excessively.

I'm also assuming that your expectations of what should happen are 
realistic based on your experience and on Sam's, etc.

Personally I don't think dead shocks would cause the problem due to being 
"too mushy".

My suggestion/guess is that you have a major bind problem somewhere in the 
front suspension as you turn in to a corner. Either a shock is binding or 
some other aspect of the front suspension is binding or is much too stiff 
(way beyond what stiff springs/bars could cause). Or the shock, etc. is 
bottoming due to lack of travel or the spring is coil binding. Maybe the 
sway bar is binding or running into something. Or the control arm pivot 
bushing is binding. If the control arm bushings are still stock did you 
torque them with the suspension at ride height or at full droop?

As a result the outside front wheel rate goes to "infinity" and the tire 
slides. I actually had that problem with a Stock Datsun Z when I added hard 
rubber sway bar end links to a relatively stiff front bar. Car would 
"randomly" slide the outside front tire on turn in. Went back to stock 
rubber bushings and the problem went away.


Dick Rasmussen
CM 85
85 Van Diemen FF 






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