From digest.v7.n535 Tue Nov 4 04:36:42 1997
From: "Carl Buckland" <buckland_at_mail.xmission.com>
Date: Mon, 3 Nov 1997 23:11:37 +0000
Subject: Neg Camber (was strange tire wear)

> Date:          Mon, 3 Nov 1997 23:52:48 -0500 (EST)

> From:          MoyaChad_at_aol.com
> To:            buckland_at_mail.xmission.com, bmw-digest_at_mailgate.wizvax.net
> Subject:       <E36 M3> strange tire wear

> Hi, Carl. Thanks for the recent posts on M3 air induction. As always, your
> opinions and experiences are enlightening.
>
> I would like your opinion, and those of the list members, on the following
> problem: When removing the Michelin MXX3's on Saturday in favor of the
> Pirelli P210's for the winter (lucky me -- it snowed Saturday night!), I
> found some very heavy wear on the inside portions of the front tires. Dinan
> just replaced for me, under warranty, my two front struts from their Stage 3
> suspension, w/ adjustable Konis. I set them for a relatively stiff ride.
> Now I'm wondering about the cause of the (apparently) excessive wear. Could
> it be:
>
> 1) the front needed to be re-aligned after installation of the new struts;
> 2) stiffness of the setting on the shocks;
> 3) over/under inflation of the tires; or
> 4) something completely different.
>
> Any insights will be appreciated.
>
> Chad Klingbeil
> 95 M3
>
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Without actually inspecting your car, I can only speculate, but it "seems" apparent: your inside edge tire wear is from the negative camber that your stage 3 suspension gives you. Neg camber is a two edged sword: it puts the tires on the inside edge, which actually *improves* tire wear on the track, or if you are only on curvy roads (tell where this paradise exists!). In a straight line, neg camber causes accelerated inside tire wear. I have *4 degrees* neg camber, and my tires don't last 500 miles on the open road. That is why I am frequently buying used tires on the Net; I use the almost worn out tires to get me to the track, and then I throw them away.

I am going to remove the (maximum) Dinan camber plates after this weekend at Laguna Seca, and run factory alignments for the winter. If I sell the car (it is still for sale), the new owner will be supplied with a half dozen MXX3's (with about 3/32 tread left) for spares, or else I will remove the plates (an easy 1 hour job).

Increased negative camber, done on the E36 M3 with plates (the shims are not advisable. that is another topic), is THE KEY to taming understeer. The front of the car sticks like glue, and tire wear improves dramatically, so long as most of the travel is on curves. In sustained straight line driving, substantial front negative camber will not only cause accelerated inside edge tire wear, but will cause the car to be a bit nervous.

I may be wrong, but I would bet a case of Lubromoly that your "problem" is your camber plates.

Carl