Visualise a straight line, which goes through the inner mounting and the centre of the spring plate/trailing arm bolts. This is the axis that you are rotating the arm about... The hub axis goes from the end of this line out at an angle.
So, if you rotate the arm, as the hub axis is not on the same axis as the rotating axis, the end of it will go up or down, giving camber change.

Does that make sense?

Sorry, I must be thick, I just can't see that. Surely the hub can only be at a position transcribed by the arc set by the forward mount of the trailing arm?

When I said;

"So I could weld an eccentric adjustable fixing onto the springplates connection holes (similar to the one on front controlarms inner mounting)?
I have understood that Porsche 944 uses something like this?"

I meant that could this eccentric adjust camber/toe as it does on 944?
This wouldnt change the ride height, but the angle of the line that draws trough trailing arms connections compared to tire.
And for clearing the subject; I am talking about camber here, nothing else this time.

Justin

Chris
Grab me at the weekend at the Volksworld show and I'll explain. My car will be in the clubs area...

Rich

:) Ok, will do (if I am going, I think I am)...

What about these camber-boxes that are common on racing Porsches?
Has anyone installed one on a Beetle?
http://www.aerotechnik.com/dijitrace/itm00066.htm
http://www.autometricsmotorsports.co...ailing_arm.jpg

Justin

Those camberboxes work wonders when installed in a Porsche. You can decrease camber after extensive lowering and it lessens diving under hard braking. Unfortunately there is not enough room in a bug unless you're handy with a large hammer :D
I haven't installed them in a bug, but I did on various track Porsches. I did however do a similar thing to a bug by elongating the holes, in which the M 14 bolthead fits, upwards and filling the bottom part with a crescent shaped piece of metal. This way I decreased the amount of camber. The reason for having too much camber was because the IRS-arm adaptors were welded in too low.
Keep us posted if you ever decide to fit camberboxes to your bug.

Cheers,

Richard

After considering those boxes a bit more I figured out that they might not work with torsionbars. Any kind of camber adjustment from the inner connection of the trailingarm would put some axial bending stress on the bars. So this leaves only one choice for camber adjustment with an stock IRS: from the springplate fixing point.
Those camberboxes would make an ultimate set-up with coil-overs, after eliminating torsion bars by connecting the springplates to chassis with rod-ends (heim-ends,uniballs).
So any opinions of my idea to add an eccentric to the springplate as on 944?
Justin

Justin,
Wouldn't the spring plates absorb the axial bending stresses you mention ? The resulting axial stresses would then be minimal IMO. The springplate also absorbs the 'normal' camber changes when the wheel goes up and down, doesn't it?

Chris,
I still don't get it either how elongated holes or excenter bolts in spring plates would change camber instead of either changing ride heigth and thus changing caster (not a misspelling this time) imo or lengthening the spring plate and thus changing toe.
The working of the camber box I understand I think.
Anyway, sometime I may learn his also...
Walter

I`m not sure of the springplates stress absorbing charasteristics, has anyone installed these in to a Beetle?
Richie; did those Porsches use torsionbar or coil-over with the camberbox?
And for the eccentric on springplate, I understand that on 944 it adjusts toe and camber simultaneously, and this only moderately. Any Porsche-owner comments on this?
Justin

Justin,

These cars had coil-overs, but IMO it doesn't matter if you use them with torsion bars or coil-overs. Just don't overdo it. Porsche moved the fulcrum (I think it's named that way?)-point 10 mm upwards in their 930 (old 911 Turbo) to reduce the rear squatting under acceleration. The 930 uses torsionbars so it seems it can be done.
Good luck,

Richard

Ok, thanks Richie. I`ll see if I can make those boxes myself.
By the way; what does IMO mean?
Justin

Sorry Justin, IMO is something I picked up during forumsurfing.
I believe it means: "In My Opinion".
Good luck and keep us posted about the camberboxes!

Richard