As above has anyone doubled up the rear ARB to make it stiffer?

Don't think you would want to double up the rear ARB. You can use uprated Whiteline 22mm (same thickness as OEM but stiffer) or 24mm. There is also Eibach which I believe is 23mm but it comes with the front ARB so much more expesive than Whiteline. General consensus here was that Whiteline 22mm is the way to go for fast road plus some track days. Whereas the 24mm for a track-oriented Coupe.

It's a very popular upgrade amongst my Saab buddies..

http://uksaabs.co.uk/UKS/viewtopic.php?f=3&t=75773

http://www.uksaabs.co.uk/UKS/viewtopic.php?f=3&t=31227

Stock rear ARB is 19mm.
Check the link in my signature.

Whiteline does not produce rear ARB now, neither Eibach or Novitec.
We are trying to male them by italian supplier.

Ultra racing 23mm is available. They come with brackets too

Final Price shipped to Europe?
I asked some months ago and it was circa 170 euros shipped + taxes, and we don t have feedback about ultra Racing...

So no one has actually tried it? I'll have to have a look to see if the ARB can be spaced a few mm from the original. Obviously the end 2/3 inches will need angle grinding off. It would be a very cheap alternative.

Can you post a simple scheme to explain it?

Pretty self explanatory.

Novitec do a 23mm Rear I've got one fitted

Interesting
Give it a go and post the results. The forum is always interested in new thoughts & ideas

interesting idea

Happy to give it a blast. Just need and old rear ARB.

Well, as they say you learn something new everyday. I hope that it won't be too stiff. Let us know.

I think that in this way you Will have a top stiff arb.
You have to take a book of building engineering and see How to calculate static moment of a 22mm circle and of two 19mm circle bar linked together, taking into account also the distance between one bar and the other.

I think that use double bar is not a good idea, no no..

It's worth a shot

The first picture makes sense as it's fully linked, the ones that are bracketed one fill me with fear, just not had time to work out why.

Phil, are you talking saabs of the vectra chassis era? The wooliest cars ever?

A couple of the photos are from Saab's of the GM era but the others are from the 9000 which handled pretty well for a barge. ARM still sell the piggy rear anti roll bar for the 9000.

http://www.abbottracing.net/product.php?id_product=103

135 gbp? We are searching for make arb at 160gbp.. But one pièce only not this strange Construction..

I was just using it as an example of what's available. If I do it it will be piggy backed with an old standard ARB. £160 Is great for a bigger rear ARB. £160 plus import tax, VAT etc + shipping is not so great. It'll end up too close to other kits available.

160 + shopping, nothing else

http://goo.gl/sCqK1D

Which = €280

Which = £205

Which = http://m.ebay.co.uk/itm/271338062333?nav=SEARCH

Some person don't trust in whiteline.. I don't know why..

Although I understand that the relationship between diameter and stiffness isn't linear, I can't help but think that TWO standard ARBs is going to be a fair bit stiffer than even the beefiest aftermarket ARB (which I believe is the 24mm Whiteline)

When I tried the 24mm, I found it too much for the road, especially with my front-end mods as well

I imagine two 19mm ARBs will have you pirouetting at every corner and it would be a nightmare on fast sweepers

Think its worth remembering the piggy Arb isn't attached by drop links etc at the ends. The space between the 2 Arbs also has a contributing factor regarding how "stiff" it becomes. I'll definitely look into this and hope to have an old ARB in my possession in the next week or so to try this out.

Think the braces between the two would be most important as these are transferring the load.
I'd have thought there position, quantity and construction would be very important.

Here's an interesting read, scroll down to the double bar section:

http://www.autospeed.com/cms/article.html?&A=112694

Nice find.

So, by my calculations, the % increase in stiffness of the options available to us are:
19mm 0% (i.e. standard)
19mmx2 100.0%
22mm 79.8%
23mm 114.7%
24mm 154.6%

Are we sure that Coupe rear ARBs are solid? (I've never hacked one in half to find out)

From reading the article linked by Jimbo, it would appear that if they're tubular, the ratios don't work in the same way

so 2 19 mm bars is app, 22.5mm equivalent?

24mm is some serious uplift in stiffness!!

Get it done and report findings. You do find this a lot with car forums. When someone brings up an idea outside the "way it's always been done" folks get all get up about it.
That's why most of our cars follow the same paths. It becomes written in stone that this mod and and that mod are the only ones to do.

I'm sure I've done something similar with a rear roll bar before but I can't remember on what, it was probably an old datsun many years ago.

I'm pretty sure the standard bars and Eibach bar is solid Nigel, it's only the later stuff that's tube section, I'm sure you'd be able to tell by the weight.
A tube has greater resistance to flexing than a solid bar.

Just do.It man!!!

I'll make solid brackets with 2 19mm holes and split them and add a bolt hole in the middle to tighten them back up. Can anyone donate an old rear ARB for me to take the angle grinder to?

I may have one lying around - never sold one, so you can have it for free

Very kind of you Nigel. Just let me know and I'll swing by and get it or drop in when I'm in Brum next.

Must admit I toyed with the idea of this a while ago. There aren't many options for my audi believe it or not - H&R or Hotchkis (from the US) and they both work out around £450.

I do have a couple of standard ones in the garage though.

I've done this in the past on my Saab 9-3 and 9000 track car. Big improvement on the 9-3.

Is yours not DRC equipped Chris?

I look forward to pictures, a report and maybe a how to!

Yep DRC. But mine has been replaced numerous times already and the next time it happens I might just stick some Bilsteins on. I do have a full spare set though.

PM sent Chris.

There's a reason for this......

As said, just do it, at worst you can reverse it If it goes as nigel says as it goes all.stiff.
VaX saab chassis was a pile of shit and needed lots of work to get it right, so a solid rear can't make them any worse.

Phil - I have a fairly shabby rear ARB for you - I've brought it home, so you can pick it up whenever you fancy dropping in

^^ ^^

Yep and you end up with this forum: Cookie-cutter cars with identical mods and tuning.

Do it Phil, I'm also interested. Uprating the rear ARB has been on my to-do list for years and this could spur me to deal with it finally!

Brilliant Nigel. I'll arrange to swing by and pick it up as soon add I'm able. I've cut some steel ready to make some custom solid hangers. Just got to drill them 19mm and split them.

Take a look at the mounting design - you may get away with simple steel plates and slightly longer mounting bolts

Feel free to drop round and I'll show you what I mean

Have you had a chance to get any further with this Phil?

No mate, not with fitting FMIC and sorting fuel pump wiring, getting live mapped and rolling roaded. Brakes are going to be sorted first then strut brace too.

Fair enough, I'll let you off...!

Cheers Geez. I promise I'll get around to it though.

Any news Phil?

Not yet pal. Been a bit hectic of late and on my Holidays at the moment. I'll get on it when I get back.

ARB is still in my shed waiting for you Phil

If doubling up using a coupe roll bar is too much, could you not use a bravo bar?
The bars on my marea are very skinny. Might just add the right amount of stiff and not be too much.

I'm on it mate. Soon as I get a free evening or weekend I'll fly over.

Looking on eper there are three different bars for the rear of the marea, the version three bar shares the same part number as the coupe.
I'm pretty sure my marea weekend has the version three fitted and my saloon has a thinner one.