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Re: <E30> negative camber

John M Mulhouse wrote:

>     As the last step in setting up my DSP 318i, I had negative camber
> added to the front wheels.  I was expecting to have the strut mounts
> slotted and pushed inward.  My reputable alignment mechanic called me and
> said that he didn't want to slot the mounts as it would completely
> rearrange the front suspension geometry.  Instead of slotting on E30s, he
> bends the strut where it attaches to the wheel.  This is essentialy
> the same as most cars where there are bolts at the bottem of the strut to
> adjust camber.  By bending, the strut tube stays at the same angle
> relative to the car, but the wheel-to-strut angle is changed.  My
> question to the digest is; what is the perfered way of adding negative
> camber to E30s?  Is my mechanic's procedure used elsewhere?  He
> mentioned to me that few shops are able to percisly bend struts.
>     I understand that negative camber can be added using camber plates, but
> isn't this the same as slotting?  With a different angle at the top of
> the strut, it would change the strut to car relationship and have nothing
> to do with wheel-to-strut relationship.  Is it better to change the
> wheel-to-strut, or strut-to-car?   As my car sits now, it has -2.1 +- .1 on
> all four wheels.  The front was changed from ~-1.5 to -2.1.  Toe was set
> at 1/16 in. in (which I specified).  I had asked for 2 1/4 - 2 1/2.  I am not
> sure exactly why he didn't add more, either he simply
> couldn't by bending the strut or he was concerned about my tire wear.

I thought about this for a week and never did like the bending of the strut,
but could not figure out what I didn't like about it until the other day. If
you think about the front strut like a gate in a fence with two hinges, you
realize the hinges must "point at" each other for the gate to be able to
swing without the hinges binding. Conversely, the strut's pivot points (the
top strut bearing and the lower ball joint connection the control arm) must
also be aligned, so that binding doesn't occur when steering left and right.

While this isn't a perfect analogy, I believe it also true for the front
suspension "hinge" points to be aligned like the gate's hinges. If you bend
the strut so that the two pivots points are no longer in alignment, it may
bind when steering, like the un-aligned gate's hinges. When moving the top 
of the strut tower (by slotting or camber plates) the strut's alignment of
pivot points is not disturbed, so it should still steer freely.

Also, after looking at my E30's front suspension today, there doesn't seem
to be a good place to bend it. Lastly, how do you guarantee that both sides
get bent equally, and that the relationship between steering, axle stub and
brake calipers isn't upset?

BTW, how did you get to -1.5 to start with at the front? Was this just from
lowering? You're probably already aware that BMW has OEM camber correcting 
top strut mounts which will give you another +/- .5 deg camber.

Evan
'87 325