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Rear ARB

20 Feb 2008, 1:00pm
Ok, still waiting for bit from Marlin, so more 'busy work'

I've got my rear ARB all painted up and ready to go on, but I seem to remember that there was a problem with the drop links to the trailing arms... IIRC, Patrick ended up using a different model BMW part...

Also, brackets for holding the rubber blocks that support it - I assume it's a DIY job? Any tips on forming them up (The blocks are D shaped, aren't they?)

Ta,

Jason
20 Feb 2008, 10:21pm
Jason,
I had numerous emails from Terry insisting that ARB's are not required and not fitted as standard on their factory built cars (despite pictures on the build CD) and hence no ARB brackets supplied anymore.
My donor didn't come with a rear ARB so that decided the rear one :smile:
My front ARB was removed from the donor and placed, uncleaned, in the corner of my lock up. It's still there supporting a whole colony of spiders. :D

It'll stay there until I've driven the car a few hundred miles,

Peter
20 Feb 2008, 10:32pm
That's interesting, as both times I've been to Stoneleigh, the Marlin show car was fitted with a rear ARB...

I wonder why they tell you one thing, and then do another? :)
20 Feb 2008, 10:43pm
I fitted them to mine. If you decid to install the rear ARB you need to use drop links from an E36 Compact, they are a lot shorter than the E30 ones - the E30 ones bash into the chassis :)

IIRC the race car had them on there, maybe the recommendation is to make the rear end less twitchy?

I've not fitted the front one, but then I've only done running in miles and not much set-up yet (was too wet for a proper chuck into the bends!)
20 Feb 2008, 10:47pm
Patrick - I don't suppose you have the part codes for the rubber bushes and the drop links do you?
20 Feb 2008, 10:49pm
Patrick wrote:

(was too wet for a proper chuck into the bends!)


That was lucky, wasn't it !
20 Feb 2008, 11:19pm
peterux wrote:
That was lucky, wasn't it !


:eusa_shifty: :tape:

GreatOldOne wrote:
Patrick - I don't suppose you have the part codes for the rubber bushes and the drop links do you?


33551135307 for the link. I used stock E30 bushes with metal spacers and Marlin's brackets (Terry can also supply a suitable bush) :)

I intended to swap the bushes for Powerflex ones at some point as the don't deform as much and act more like a ball joint.
21 Feb 2008, 11:56am
Patrick wrote:
I used stock E30 bushes with metal spacers


Spacers?
21 Feb 2008, 1:06pm


Yellow bit is the spacer, blue bit standard bush. I didn't use the Marlin one (hard plastic type) and sent it back (as I hadn't ordered it but was sent with the brackets).
21 Feb 2008, 1:10pm
Ahhh, everything becomes clear.

I've ordered e30 bushes from the local stealers, and I'm making my own brackets, so I shouldn't need the spacer.

I'm picking the drop links up from GSF on the way home - they happened to have them in, and a £7.00 each, they're a lot cheaper than the BMW parts counter! :)
21 Feb 2008, 2:17pm
The diff bracket might get in the way using the standard depth. I took a tiny bit off mine.
21 Feb 2008, 2:26pm
ARBs

Marlin continually change their minds about a lot of specs.
I have the Sierra front suspension, which uses an ARB to double up as a forward/backward link for the track control arm. On other Cabrios with BMW engines I've seen, Marlin modified the ARB by shortening the forward length, and fitted the support brackets closer to the front of the chassis, presumably to avoid fouling the sump.
So I sent mine to Marlin for modification and this is what I received back!
Two separate stub arms -
see [url]www.flickr.com/photos/mikes_bmw_marlin-Cabrio/Complete[/url] anti roll bar

I have trial fitted my engine and found that I can fit a complete ARB without fouling on the sump, so I will have an ARB.

This raises an interesting question - is the sump on a 325, different to the sump on a 525? I have seen M50 engines with the oil sump at the front, and at the back of the engine. My own, from an E36, has the sump at the rear, which allowed me to fit the complete ARB. Marlins demonstrator had the sump at the front - hence the modified ARB.
I assume Marlin do not feel an ARB is necessary on the front?

Ps
How do you download pictures on to this site? I just tried and my single photo was 4MB, and the limit here is just 98KB?
Pps
How do you generate a direct limk to another site - as I've tried to do above?

Mike
21 Feb 2008, 2:53pm
A two part ARB... Right... :)

The sump on the M20B25 engine (e30 325i) is at the front of the block:




I'm not going to have a front ARB. My wishbones have no mounts for them.
21 Feb 2008, 5:32pm
Mike wrote:

How do you download pictures on to this site? I just tried and my single photo was 4MB, and the limit here is just 98KB?
Pps
How do you generate a direct limk to another site - as I've tried to do above?

Mike


Best way to display pictures is using the [img] tag. For example:

[img] url of picture here [/img]

where your picture is hosted somewhere else - for example flikr

Normally to get a direct link to another site you just paste it in and it takes care of it automatically.

Patrick is the expert, I am just an old hacker....

Best

Robin
21 Feb 2008, 10:00pm
GreatOldOne wrote:

I'm not going to have a front ARB. My wishbones have no mounts for them.


Ah, so the newest type wishbones don't have ARB mounting points. I guess that decides the fate of my old donor ARB then.
I guess the stress on the the wheel end of the wishbone will be greater if an ARB is fitted to 'stiffen' the wishbone.
Imagine hitting a large bump in the road, the wheel wants to go up and the spring, damper and ARB are all trying to hold the wishbone stationary.