Rear Beam Arb

[ifcho 0]

Hi,

 

I posted a topic yesterday about adjusting the stadnard rear beam. After thinking about my idea I came to the conclusion that it is will not work as I was thinking it, but as somebody else had tried something similar I thought we may continue the discussion

This is the main idea:

 

Generally if you can adjust the lever arm of the ARB you will be able to change its stiffness. However with the rear suspension setup on Peugeot's I'm not sure that this can be done at all while retaining the original ARB. The reason is that the actual lever arm is not the plate that connects the bar to the arm, but it is actually the radius arm itself.

Edited October 5, 2007 by ifcho

[Rippthrough 98]

Where did that thread go?

 

Anyway - the above picture won't work, as the arb still moves through the same radial arc as the trailing arm, like I said, you need a seperate pivot

[Pugnut 9 1 Cars]

all the above will do is shift preload on the arb from one side the other. possibly even making the car lean to one side . completely pointless unless you always go round corners in the same direction

[taylorspug 7]

Regarding the above 2 comments, its on my car and it works very well. Ok its probably not as effective as say the Whiteline kit, but the different hole settings do change the cars balance.

 

How is it going to make the car lean to one side/why are you talking about preload? Ive not preloaded anything, both sides of the ARB are like that and the rose joints are adjusted so there is no preload on the ARB at all. And my car doesnt lean to one side so...

 

EDIT: The original thread has been lost in the server crash thing that happened last night.

Edited October 5, 2007 by taylorspug

[Pugnut 9 1 Cars]

ah right i see , i thought the adjustment was on the tread rod , i didnt really pay attention to the holes .

 

but the arb will still have the same torsion over the same travel of the radius arm wont it? .

[ifcho 0]

After doing some more research, I found the solution:

[Rippthrough 98]

After doing some more research, I found the solution:

 

 

Like I said - it needs a seperate pivot.

[Pugnut 9 1 Cars]

is that the whiteline one?

[Rippthrough 98]

No, the whiteline one bolts up behind the beam on a system of clamps and rubbers - that one looks like a grasstrack/rally special

[Tom_Fowler 0]

The setup in the 1st picture of the ARB in the origional location and droplinks to the arm is in no way an adjustable arb, as the lever arm for the arb will always be the length of the trailing arm no matter where the drop link is attached.

 

The later pictures are from a french rally preperation company I believe called KRS and is a copy of the system used by peugeot sport on numerous torsion bar Rally cars. This works because the arb is on a different pivot to the rear arm. Another interesting feature in this setup is the link you can just see attached to the damper mount. This link goes to the rear arm in order to increase the toe stiffness of the trailing arm.

 

Tom

[ifcho 0]

Yes, this is from KRS.

 

Has anyone tried to do this?

It does not look too hard to be made, just two plates welded to the rear beam with a bush for the ARB and two connecting plates.

Actually the plates with the bush are the hardest think to make, I was thinking of a bearing, but I guess the surface of the ARB is not very suitable to be inside a roller bearing?

[Tom_Fowler 0]

I had a look into this before and decided against it in favour of just having different sized bars. As the level of adjustment in stiffness available is not a very big range compared to using different bars. Also my car is for use on gravel and running the arb outside the tube will reduce the ground clearance and the bar would probably be smashed off.

 

The arb brackets onto the beam would be need to be machined or fabricated in order to get the thickness to support the arb bearing a simple sheet would not have the stiffness or depth for the bearing. The best thing to use for the arb bearing would be a nylon bush. New ARB's would also need to be made as the std 205 one the spline is bigger than the diameter of the bar and therefore the bearings could not be fitted onto the arb. The lever arms could be made from std ones modified and drop links are easy.

 

Tom