Front Offset Bushings

#1

I bought some offset bushings for the front control arms and have been looking over them trying to decide which position is best.

I found: http://www.bmwe30.net/cgi-bin/datacgi/database.cgi?file=articles&report=view&ID=00139&Section=05

Which makes sense: if the bushing’s hole is closer to the frame rail the result is locating the ball joint slightly forward and in. hole away from rail = ball joint back a bit.

My question is, which makes more sense in people’s experience? Or is it somewhere in between.

Thanks,
Gareth
’87 is - suspension almost completely in.

#2

there should be orientation marks on the bushing so you get them both right.

#3

I’m no engineer, but mine are set with the hole closest to the frame rail, which should allow for more camber.

Ed
[attachment=81]caboffset.jpg[/attachment]

#4

nasaregistrar wrote:

I think had I bought stock bushings they would have a mark, but these don’t have marks like the stock ones do. They look much like the urethane part of the ones posted by edavidson. They do have machining marks on them every 120deg so that will aid correct placement once I decide how I want them orientated.

So is camber what I should be after? Anyone run them 180 deg different or somewhere in between?

Thanks,
Gareth

#5

edavidson wrote:

Just thinking about that… shouldn’t that provide for more caster and slightly less camber? Since it will locate the ball joint forward but inside its stock position.

Gareth.

#6

I might be wrong, but my understanding is that the purpose of these offset bushings is to provide more caster for greater steering stability. My car came with the M3 offset bushings installed by a local BMW guru and the hole is either at zero or 180 (I cannot remember which), but not in between.

Sasha

#7

The offset bushings increase caster

#8

ok. Sounds like the stock m3 position is whats intended - hole closest to frame rails for increased caster.

Thanks for the help.

Gareth

#9

That does make sense, Gareth. If it were 180 in the other direction, caster (not camber!) would be less than stock, since the pivot point is the center ball joint on the control arm.
Ed

#10

The later E30 M3s came with the offset control arm bushing to increase caster and improve straight line stability. This has become the standard upgrade for the earlier cars. This is the way I have mine installed.

Post edited by: m3donnelly, at: 2006/06/08 19:49

#11

Thats how mine went in. Thanks for the confirmation.

Gareth.

#12

thank all for this post, this was the exact question I was trying to figure out with my offset bushings.