Rear ARB on 86 90 quattro

[msh]

Originally Posted by Laaf

It's the previous owner who fitted the brakes. The calipers uses adapters to fit. And redrilling cheap A4 288 mm discs come much cheaper than renewing 3 sets of rims and tires.

Well, B3/B4 G60 discs shouldn't be very expensive either, I'm only wondering if they would relieve you of the need of adapters or not, as I think that two piece struts have different offset than one piece. But you can also do it properly and make front suspension upgrade - since you already have Bilstein B6 shocks for "civilian" B2/B3/B4 struts, you have no need for S2 struts, as for the rest, the donor is B4 2.8 - since you're talking about 4000, I presume you're in states, so such donor car should be easier to find for you, as it seems to me there weren't smaller engines for US market [am I wrong? ] - only it will involve fitting outer CV joints on front driveshafts [if you're still using B2 gearbox] and it will involve changing front brake lines, because they end in different place because of shape of anti rollbar, which don't permit using the old brake line setup. Afterwards you can use B3/B4 G60 discs and no need for adapters for calipers, or you can go for 5x112, which involves expensive and hard to find S2 hubs or, more often, turning some C4 hubs to fit, as they require small reshaping for this application. Afterwards, ordinary B4 G60 discs can be redrilled, or S2 discs fitted, only they are quite expensive and hard to find. Since I don't like both of these options, when I'll finally go for 5x112, I want to try what happens if B5 front hubs are fitted together with B5 discs - will they line up with G60's or offset will be different - and I wouldn't mind if someone would check that out before me Rear 5x112 upgrade has been found by some to be very simple - B5 quattro rear hubs [on such a old cars that involves rear outer CV joint or whole driveshaft swap] and brake discs, and that's about it.

[Laaf]

Originally Posted by Andy10v

If the mounts for the droplinks are still on the struts you could make something the same again. Or as MSH says swap to a setup with an ARB.

I am running an S2 bar on the front and back, seems to work well, though it will lift the inside rear wheel on a very steep uphill hairpin bend.

You can also use the older front arb that mounts to the wishbones.

Couple of threads on S2 forum concerning front arbs on the rear (with a rarb setup already installed.

http://www.s2forum.com/forum/showthr...&highlight=arb

http://www.s2forum.com/forum/showthr...&highlight=arb

There is a few different fr arbs you can mount on the rear, S2 is 26mm iirc, so you can fine tune.

Whitline also do an adjustable one.

The mountings on the uprights are still there so it wouldn't too much of a hassle mounting one again. Had a brief look on german ebay and found a new Sport Quattro ARB. Looked around google a bit and found it to be 15.5mm of diameter so I guess it would not make much of a difference getting the rear end a bit more lively on the track.

Well, B3/B4 G60 discs shouldn't be very expensive either, I'm only wondering if they would relieve you of the need of adapters or not, as I think that two piece struts have different offset than one piece. But you can also do it properly and make front suspension upgrade - since you already have Bilstein B6 shocks for "civilian" B2/B3/B4 struts, you have no need for S2 struts, as for the rest, the donor is B4 2.8 - since you're talking about 4000, I presume you're in states, so such donor car should be easier to find for you, as it seems to me there weren't smaller engines for US market [am I wrong? ] - only it will involve fitting outer CV joints on front driveshafts [if you're still using B2 gearbox] and it will involve changing front brake lines, because they end in different place because of shape of anti rollbar, which don't permit using the old brake line setup. Afterwards you can use B3/B4 G60 discs and no need for adapters for calipers, or you can go for 5x112, which involves expensive and hard to find S2 hubs or, more often, turning some C4 hubs to fit, as they require small reshaping for this application. Afterwards, ordinary B4 G60 discs can be redrilled, or S2 discs fitted, only they are quite expensive and hard to find. Since I don't like both of these options, when I'll finally go for 5x112, I want to try what happens if B5 front hubs are fitted together with B5 discs - will they line up with G60's or offset will be different - and I wouldn't mind if someone would check that out before me Rear 5x112 upgrade has been found by some to be very simple - B5 quattro rear hubs [on such a old cars that involves rear outer CV joint or whole driveshaft swap] and brake discs, and that's about it.

I'm actually in Finland. Here's a bit more info on the car. http://www.classic-audi.co.uk/forum/...ad.php?t=27697

Regarding a 5x112 conversion I've concluded I won't do anything about it until I'm forced to.

[20vcqdriver]

Fitted one to mine way back in 1997 and one of the best mods I've done, reduced the understeer and removed the rolling rear of the csar and made the whole car more stable.
Have a article on mine if interested, just PM your e-mail address.
Having driven a few 'normal' ones it confirms it is a worthwhile upgrade.

[msh]

Understeer or oversteer?

Btw, how it happens that your middle silencer does not interfere with driveshaft, despite being wrong one?

[Andy10v]

Originally Posted by msh

26 mm is the diameter of front ARB of V6 and S2. Presuming the rear subframe is about the same size as front, I don't see any way to fit front ARB in rear, as the front ARB is made to fit links fitted on the opposite side of struts. That aftermarket rear ARB one member showed me was 18 mm, I presume stock ones will be one or two milimetres thinner.

Actually I've read in the internet interesting way to get rear anti rollbar, which involves fitting Typ85/Typ89 front wishbones and ARB in the back + making some mounts on subframe for that ARB. That would be 22 mm ARB if taken from FWD car or 26 mm if taken from quattro. That would be a hell of a ARB

You just swap the struts side to side and that puts the drop link mount in the right place.

That's like I mentioned above, early wishbone mount arb, some of the wishbones you can buy actually come with the bushes installed.

[Andy10v]

[quote=msh;325258]Understeer or oversteer?
QUOTE]

I think the front bar on the rear makes the car fairly neutral, you can provoke understeer or oversteer as required. As stock they tend to understeer unless you are particularly forceful.

Car corners much flatter as well.

[msh]

You're probably talking about tarmac, while I'm thinking about gravel, because the rear end of my A90q has a strong tendency to slip out of the corner, which should not happen, and which is probably caused by incorrect geometry adjustment, as the front and rear appeared to be in different angles. Will try to adjust after the rear end of the car will be in one piece again.

How nicely front ball joints fits in rear struts? Just interest, I won't fit anything like that, despite having most of the needed parts at hand, because it would cause my car fail technical inspection without any doubt.

[20vcqdriver]

[quote=Andy10v;325267]

Originally Posted by msh

Understeer or oversteer?
QUOTE]

I think the front bar on the rear makes the car fairly neutral, you can provoke understeer or oversteer as required. As stock they tend to understeer unless you are particularly forceful.

Car corners much flatter as well.

Thats my conclusion too, I used the front bar from an early quad lamp GT (20mm) modified to suit.

[Andy10v]

Originally Posted by msh

You're probably talking about tarmac, while I'm thinking about gravel, because the rear end of my A90q has a strong tendency to slip out of the corner, which should not happen, and which is probably caused by incorrect geometry adjustment, as the front and rear appeared to be in different angles. Will try to adjust after the rear end of the car will be in one piece again.

How nicely front ball joints fits in rear struts? Just interest, I won't fit anything like that, despite having most of the needed parts at hand, because it would cause my car fail technical inspection without any doubt.

Yup, driving on tarmac. I assume gravel is somewhere between tarmac and snow? In snow it is much easier to kick the back end out. You can do the same thing on tarmac but need to be much more aggressive/and/or have much more power to break it loose.

Getting the car properly aligned makes a huge difference to handling! (Though bushes need to be good or you get changes in alignment as they deflect)

Never tried front ball joints in the rear.

If you use all factory parts (especially used ones) the nobody will notice unless they know the cars very well. Also as there were early cars with rear arb, then ones without, then arbs again, also different diameters.

[Error404]

I recognise that rear subframe. Sadly it is less shiny these days, 5 years of abuse have taken their toll!
That was a 22mm rear bar, matched by a 26mm S2 bar up front and it was an excellent, cheap setup.

As said uprating the rear roll stiffness of these chassis cars is pretty much the best handling mod you can do to an otherwise stick car and I would say essential if you are doing any track driving. When dialled in right it makes the balance far more neutral and understeer can be completely eliminated with appropriate driving. Lift-off oversteer is also a welcome addition - makes the car into a giant hot hatch. Add a Torsen rear diff too and you are into a whole different league of fun