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rear 1/2 of twin - shock tower tech - inputs welcome



a few comments interspersed...


> initial background - intend on fitting complete
> front 16v suspension +
> engine in the rear.

OK. Sounds good.

> - i plan to use coilovers (possibly ground control),
> and therefore it may be
> possible to keep the stock body as far as strut
> towers go (if the shoe
> fits...).

Er...it doesn't. At all. Normal front suspension is a
strut. Normal rear suspension is a shock. Besides the
fact that a strut bearing would in no way fit in the
rear shock tower, you also have to remember that a
strut is a damper **and** a load-bearing suspension
member. A shock is just a damper. Thus, the rear shock
towers are not designed for fore/aft/side loads.

> keep in mind i would reinforce the towers,
> so there would be no
> problem there.

Well, as per above, your best option would be to cut
them out completely and box-in a proper strut
tower...or make it part of the subframe like the one
in the picture.

> For the techies, the
> rear kingpin/caster angle is almost the same using
> the stock tower points in
> the rear as compared to the same suspension as it
> would be in the front
> (just fyi).

Unless you plan to have 4-wheel steering, caster
doesn't matter except that it will reduce your
effective spring rate slightly. It matters on the
front because it affects camber when the wheels steer.

> - problem: i need bearings vs. bushings (like in the
> pic). I'd like to keep
> the stock mounting point as far as the strut towers
> go (so that i dont have
> to cut/weld the mount points). the reason i stress
> bearings at all is that
> im not sure if standard type rear inserts will do
> the job (from a
> maintaining alignment perspective, as rear alignment
> will no longer be
> determined by the tortion beam). the slightest shift
> (even in poly) may have
> large effects in alignment.

Not following you here. Every car out there comes with
rubber control arm bushings, strut bearings, and ball
joint bushings. They all work fine. Poly is much
stiffer than that. What's the problem?

The rear control arms in the picture looks like they
were stolen from something else. They are definitely
not A1 control arms. In fact, I don't see anything
that would equate to a tie rod, so I would bet they
came out of some RWD car with rear strut-type
suspension. You can also see that part of the subframe
where the control arms are connected looks to be
stamped metal. My guess is that they took those pieces
from the donor car's subframe and welded them into the
custom tubular subframe. Smart idea. All you'd need to
do is find the right size wheel bearings...

> - question: so are there any upper strut bearings
> that anyone can think of
> that may be adaptable to the stock rear tower mount
> points? the ones in that
> last picture look close, but they also look like
> they rely on the shape of
> the tower to fit properly (meaning i would have to
> cut those 2 sections off
> of a car and cut/weld on the rear of the twin).
> - basically im trying to maintain as much stock
> structural integrity in the
> rear tower area.

No part of the strut towers in the pictures is
original. Definitely. look at the last pic in
particular. They welded some thick plates to the
tubular subframe to fabricate a mounting point for the
strut bearings. You can see where the old body shell
goes behind it all. Those bearings don't look like any
I've seen before, and they're definitely not rear A1
shock bushings.



Neal


=====
~Neal

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