Cosworth 3 door with a 4x4 rear anti roll bar
 

Hello
Can any one show me some pictures of a 3 door Cosworth with a 4x4 saf rear beam set up need to see how the rear anti roll fits I am trying to fit the 4x4 18mm thick roll bar and I don't no what drop links to use
Thanks for your help

To fit a saph, escort or granada of arb to a 3 door, You have to weld mounting blocks to the chassis member at the rear to mount the arb brackets and you use the saph drop links and weld mounts to your rear arms to suit to fit it on a 3 door, really easy job to be fair, I fitted a 21mm granada one to my 3 door (rep) project

Pictures speak a thousand words

This is what I made to mount the arb bracket on, i made them from one piece of steel cut then bent and the corners welded together, then cut the flanges off, cut a slot in for the arb bracket then drilled a hole and weld a captive nut inside

Attachment 23149
This is the location of the arb bracket mounting blocks, this is before I painted everything up
Attachment 23150

This is the bracket I made to weld to the arm to mount the drop link

Attachment 23151

You can make out the location of the brackets to bolt the drop links to on this picture
Attachment 23152

If your using sapphire arms with arb mounts ignore the last part

I had sapphire cross member fitted to mine,looks factory rather than weld 2 boxes on! but now gone bladed rear ARB

Hello thanks for the help

I got the sapphire ream beam as we'll so if I fit the rear beam from a sapphire I can fit the shorter sapphire 4*4 rear anti roll bar without doing any welding
Thanks Darren

Hi this thread is just what I was looking for, as I have a mk2 xr4x4 rear beam I am putting on a mk1 xr4i. Can you remember the size of the boxes you made up. Do they have to be a certain depth so arb sits on the right height. Also could I bolt the boxes to the car instead of welding. Thanks

You can bolt the boxes to the car instead if you wish as long as they are secure, I can't remember the size I made them, if your stuck I can measure them for you, I took the rough measurements from my saph iirc

That would be great if you could measure them, was going to buy a 3dr roll bar as its thicker than my 10mm xr4i one and weld tabs onto my mk2 arms but think I should just fit a mk2 arb as they should be better still than a 3dr one

Just been out and measured it, the box is 40mm tall, 68mm wide and 80mm long.

The xr4x4's arb is 14mm the same diameter as the 3 door cosworth iirc, doing it this way opens up the options if you want to go thicker the 2wd saph cosworth is 16mm, 4wd is 18mm, granada cosworth is 21mm and Escort cosworth is 22mm

Many thanks for your help mate, that had helped loads. Saved me hours of faffing around trying to get it to work right

Old thread but does anybody know the benifit of a 4x4 rear arb over a std 3dr?

Cheers

Hi mate,

Yes. Working from memory differences are as follows.
Std 3dr roll bar is 14mm and mounts across the outside edges of trailing arms
2wd saph is 16mm - mounts on inner of trailing arms. Less width has got to be good for reduced flex etc thus better resisting roll.
4wd saph is 18mm i believe approx 1.5 times stiffer than 3dr 14mm
escos is 22mm and i believe 3/3.5 times stiffer than 3dr.

to my mind running with an arb allows lower springs rates softer damping. So you could for instance have it fairly soft at the back for good squat and launch but still have good roll resistance in the bends.

Some say running with no arb is fine.
personally i prefer a rear arb. I run the std 3dr one on my car. Thats with gaz golds and adjustable 6 degree rear beam. Seems to handle well to me.

I am a internet keyboard warrior and no expert. Dont flame me just my opinion.

in other news your old 200 mountune block is absolutely tip top and loving life in my 3dr. Goes well for a mild 360 i tell thee.

Hi Jamie. How did this pan out? Any pictures?
Some people in old discussion threads have suggested that the 22mm arb is to stiff in a 2wd car. How did you find it?

Thanks for that mate, glad that engine has been good for you 😎
I'll be rebuilding my saph engine for the 3dr the focus cossie project got scrapped bought a 3dr 😎

Of the mk2 Sierra type there are actually quite a few different sizes. I did a calculation of what the stiffness is supposed to be based on this formula:

https://farm5.staticflickr.com/4491/...fd22a217_b.jpg

https://farm5.staticflickr.com/4470/...383f4696_c.jpg

14 mm - 7.96 N/mm (Sierra XR4x4)
16 mm - 13.59 N/mm (Sapph Cosworth 2wd)
18 mm - 21.76 N/mm (Sapph Cosworth 4wd / Granada 24v)
20 mm - 33.16 N/mm (bug-eye Scorpio)
21 mm - 40.32 N/mm (bug-eye Scorpio 24v)
22 mm - 48.56 N/mm (Escort Cosworth)

As you can see the stiffness goes up very quickly with the diameter. A 3dr arb is also 14 mm thick, but is a lot longer than the later type arb so will be quite a bit softer. At a guess it might only be something like 5 N/mm.

I have a 21 mm Scorpio 24v rear arb on both my cars. I also used droplinks with rosejoints which give quite an increase on the arb stiffness as well, as the rubber in the standard droplinks is quite soft. What size is best depends on the rest of the suspension, so front arb, springs, shocks, etc. So it really is trial and error. But I'd say that around 20/21/22 mm is a nice size. Of course it also depends on what you personally like. When it is about being fastest on the track a softer rear arb on a 2wd car might actually be better for getting the power down.

Thanks for that marc apreciate it I had full 4x4 running gear for another project so using most of it 4x4 6 deg beam supra diff and 4x4 front arb I think I have a 2wd saph arb also it will be fast road not much if any track, be around 400-450 on coilovers gaz golds
thanks again mate 😎