Coupe Rear ARB options aka FARB on the rear of a coupe

[Jamo]

This is a really good thread. Thanks Andy and others for the effort. Does anyone have any experience of the Neuspeed RARB as I am considering fitting this to the RS2, to reduce on-power understeer, and hopefully make the car a bit bit more neutral through the bends....

Any feedback comments appreciated.

Guides and top-tips

http://www.s2forum.com/forum/showthread.php?t=5214

[Rusty]

Cheers Will. This is looking more hopeful. The 7A one should be 25mm? Does yours use the standard S2 metal drop links rather than Doug's setup of Saxo DLs?

[WabTheKing]

Cheers Will. This is looking more hopeful. The 7A one should be 25mm? Does yours use the standard S2 metal drop links rather than Doug's setup of Saxo DLs?

sure does!

[Rusty]

Looks like a winner then!

[Rusty]

Thanks to Alex at All Audi I now have a 24mm and 25mm FARB sat in the garage. The bars are identical to the S2 (except diameter obviously). Also got some used bushes and drop links to do a dry run, will replace all of these when I'm happy with the fit etc. Hope to have a play with all of this in the next month as I'm currently ill at home and off on a skiing holiday next weekend so need to recover for that!

I'll try and find a 23mm FARB to compare with the other 2 when I've got it all fitted, thinking that as there's no chance I'm shelling out £250 for a new RS2 FARB then I've got to go a little softer on the rear . Should give a similar stiffness ratio front to rear as Tom had

Pictures to follow as and when I get round to it. Oh and all the other jobs that I want to do before the 'ring and Le Mans...

[Rusty]

Update:

Finally got round to having a play with the rear suspension. Have fitted a 24mm FARB onto the rear .

Swapped the struts from side to side to relocate the DL mounts (still have to swap the ABS sensor cable mount but that's a small job that can wait for now). The FARB is completely bolt-on with no modification required to any parts to make it fit. Front cups and bushes are required and fit without any problems.

Only problem I encountered was that with the wishbones hanging, the DLs touch the wishbone edges, with the car on the ground they are nearly 2" clear so not too worried. To overcome this whilst fitting the ARB, I just jacked up the hub and all fitted well. There is a slight clearance issue between the handbrake cables and the drop links. I'll keep an eye on this and will be looking at re-routing the handbrake cables if I keep this ARB setup, although with the car on th ground there is a lot more clearance so I'll have to see what happens! Adjustable drop links might be worthwhile if you're looking at doing this as they would allow more of a gap when fitting and aren't much more expensive than the standard ones have become.

Spec:

• Koni dampers
• Standard springs
• Front 26mm FARB - standard S2
• Rear 24mm FARB.
• 16" alloys with 225/50R16 Eagle F1s (40PSi from motorway trip yesterday).

Road Test:

Bit hard to do a back to back comparisson as I didn't go out for a thrash before doing the job to fix a benchmark in my mind . The car seems to love tighter corners where it would have struggled for front-end grip before. Much improved, used a local small roundabout as a handling test and was very impressed with the change! The handling is more neutral on bigger, sweeping bends and nicely adjustable at the limit of adhesion on big motorway roundabouts etc. without snapping (as you'd expect with standard spring I suppose).

The 24mm item on the rear with the 26mm at the front is not too much, does not make the car undriveable or anything silly like that, TBH I quite like it and would describe it as a worthwhile upgrade for those wanting a scrap-yard mechanic upgrade.

The stiffer and softer options that are available make it a good choice if you're looking for the option of adjusting the handling of the car over a wide range.

If I decide to keep the upgraded ARB, I have new drop links to fit and will get a new set of cups and bushes to suit whichever ARB I go for.

Verdict:-

not bad for £25!

[v8 coupe]

I am doing this to My 7A CQ. The RS2 unit is headed my way now I already have the later US build CQ FARB mount in the front so it will go to the rear and I\'ll use stock rear strut tubes. I am not going to be found with these being weak as every piece of the suspension is being strengthened. I am welding the stamped rear arms solid, I am welding both front and rear subframes, as I am also welding the front steering arm and clearancing it for some massive tyres. The car will have a RS2 FARB and 20v CQ rear (24mm) FARB with custom drop links. The car will also have coil overs, koni shocks and a torsen rear. Basically this will have the most agressive setup I can get using mostly stock parts.

Spring rates will most likely be 400 front 450 rear with dual adjustable konis.

[Rusty]

You could run an RS2 FARB on the rear if you were feeling brave! unless you're talking about the early CQ FARB which Doug used. Torsen should make things a little more interesting too!!

[v8 coupe]

I could and I might try. I will have 2 CQ FARB\'s late build for use with the drop links just like the RS2. I\'ll be making custom adjustable drop links as I don\'t like any of the options I\'ve seen. The rear will be quite stiff as I\'ll also be adding a rear strut tower bar with multiple direction stiffness. This is all in a relatively stock looking CQ mind you so i will have one beast of a car.

The other thing is I am considering using a second set of front strut tubes in the rear minus the steering arm of course. This would make fitting the koni\'s easier.

[Rusty]

Bit if an update for everyone:-

Having had a 24mm and now 25mm bar on the back for about a year I can report that this really is a worthwhile upgrade and I'm sure that anyone who's been round a track in the car would confirm this. I'm still on stock springs with Konis and a 26mm front bar (as the RS2 items are sooooo expensive now). My recent track day at Donington did highlight that the 26F/25R option is a little too aggressive for very slippery, wet conditions but in the dry it's perfect if you like the car to slide around a bit, it only understeers on the power and mildly oversteers off the power so is very predictable and controllable. It now turns in sufficiently to allow for much more aggressive driving and a bit of fun / showboating when required!

[S2central.net]

@Andy - Just to refresh my brain on this one, after a quick skim of previous posts.

Do I understand correctly that you are running stock S2 FARB (26mm) up front and a 25mm FARB from an 80/CQ at the rear and the only mod required was swapping the rear struts over ?

Paul

[Rusty]

That's basically correct 26/25 is fine for dry track use but is a bit much in the wet unless you like things to be a bit sideways (and I do!).

You'll also need the front ARB cups and bushes of the correct size and it needs a bit of fettling with the handbrake cables and brake lines but if you go for longer braided hoses then this will not be an issue. I have some sacrificial coolant hose on the brake lines to protect them where they rub on the drop links. When fitting the bar make sure you jack up the wishbones otherwise there's a slight clash between the ARB and wishbones, this does not occur in normal driving.

HTH

[quattro84]

Update Excel spreadsheet attahced.

Nice Thread.

Just a comment,
In your spreadsheet you calculate the Polar-moment of the bar as an solid piece.
Why? because you don't know the wall-dimensions i guess. Then the formula should be
Phi/2*(R_out^4 - R_in^4). Think that'll make some difference in the comparance between the bars.
P.s. If you do know the wallsize and the material type it would be nice to calculate the angle of twist. Would help me for my calculations (http://www.s2forum.com/forum/showthr...91#post282891).

[Audi_CQ]

Nice Thread.

Just a comment,
In your spreadsheet you calculate the Polar-moment of the bar as an solid piece.
Why? because you don't know the wall-dimensions i guess. Then the formula should be
Phi/2*(R_out^4 - R_in^4). Think that'll make some difference in the comparance between the bars.
P.s. If you do know the wallsize and the material type it would be nice to calculate the angle of twist. Would help me for my calculations (http://www.s2forum.com/forum/showthr...91#post282891).

The ARB's are solid

[quattro84]

The ARB's are solid

Are all of the OEM's? A lot of aftermarket stuff like Hotchkis and Strano isn't.