A question about rear suspension geometry and setup.

[Charlie Farley]

I'm on the case this weekend for some rear spacers , i have experimented with several wood spacer templates in varying widths to get the best possible idea on look and fitment.
What i have determined is that 10mm is optimum, possibly 12mm max , but before i take the next step i wanted to be clear of the geometry setup involved with the rear suspension.
Does the wheel stay in a vertical plane when moving in upward or down stokes of the suspension , or does it move inwards slighty as the wheel moves upwards within the wheel arch.
This may sound like an odd question but it may determin what size spacer i use , if moving inwards then 12mm will be good, if it stays in a fixed vertical plane then 10mm will be max otherwise contact with inner wheel arch will occur.
hope this makes sense and someone can clarify things.
rgds
rob

 

[gary_a4_quattro]

My short answer; I'd say the rear wheel moves in an inward facing arc, the centre being a 'point in space' somewhere between the centre and the opposite side of the car.

As a practical 'old school' method to check, enlist the help of as many 'robust' mates as you can and get them to sit in the rear to compress the suspension move the car a few yards to allow the suspension to settle and do a couple of measurements, before and after loading, using a ruler off the top and bottom off the wheel rim and a plumb line to see what the camber change is under compression. Or enlist the help of your local builders yard and borrow some bags of ballast and load 'em in the back !!! That should give you a fair indication of the movement

Found a drawing on audizine about halfway down the thread:
http://www.audizine.com/forum/showt...Audi-A4-(B7)-Long-Version-(56k-grab-a-snack!)
There's a drawing of the rear suspension assembly which would tend to support the above supposition.

Rob, Hope that helps a bit and be interested to hear how it goes

Gary

 

[tony mc]

hello, i've got 15mm spacers on the rear of my avant, and they've been on a while now. i am into my fishing and shooting so my car is always full of people and gear for both sports and i kind of use the car like a little 4x4 crossing fields and farm tracks, and as of yet mate i have had no issues with rubbing and the car is lower than standard by about 10mm, hope this helps you a little too.

 

[SDHA4SLine]

hello, i've got 15mm spacers on the rear of my avant, and they've been on a while now. i am into my fishing and shooting so my car is always full of people and gear for both sports and i kind of use the car like a little 4x4 crossing fields and farm tracks, and as of yet mate i have had no issues with rubbing and the car is lower than standard by about 10mm, hope this helps you a little too.

Is yours an s line?

 

[tony mc]

yes mate, mine's an s line

 

[Charlie Farley]

right then, been on the case again today, loaded the back with a shed load of stuff and got the measure on it again.
With the dtm's having an offset of ET43 a 15mm spacer just wont go without inner arch contact, 12mm will go but touch a small amount, 10mm are fine and are probably the way to go. The actually change in angle is very little to be honest, i suspect the ET43 offset is the main reason for only getting a 10mm spacer on safely.
Next problem is finding a 10mm spacer that will work as the hub has a spigot that is 13mm deep.

My short answer; I'd say the rear wheel moves in an inward facing arc, the centre being a 'point in space' somewhere between the centre and the opposite side of the car.

As a practical 'old school' method to check, enlist the help of as many 'robust' mates as you can and get them to sit in the rear to compress the suspension move the car a few yards to allow the suspension to settle and do a couple of measurements, before and after loading, using a ruler off the top and bottom off the wheel rim and a plumb line to see what the camber change is under compression. Or enlist the help of your local builders yard and borrow some bags of ballast and load 'em in the back !!! That should give you a fair indication of the movement

Found a drawing on audizine about halfway down the thread:
http://www.audizine.com/forum/showt...Audi-A4-(B7)-Long-Version-(56k-grab-a-snack!)
There's a drawing of the rear suspension assembly which would tend to support the above supposition.

Rob, Hope that helps a bit and be interested to hear how it goes

Gary

thanks for the link gary, really good info

 

[ajax1976]

I've searched many times for such a thing and came up with nothing although others say they are available but never seem to post a link to them.

I had FK ones and when I looked at them I actually found it hard to believe that it is even possible to machine a 10mm that would fit over a 13mm hub, there just isn't any material there to work with. I ended up shaving back my hubs which sounds drastic but it worked for me. When you look at the hub closely you can see the wheel actually sits on a thin lip that runs round the hub so the material I removed served no purpose. If you make a tidy job of it you can even refit the cap.


Have you considered dropping back to a 8mm? If you used a plain/flat 5x112 spacer it might leave enough of the hub protruding through to still mount the wheel? Would be cheaper too.

 

[Charlie Farley]

thanks for that info , one question though, is that from a quattro or fwd avant as my hubs dont look like that and dont have hub caps either.
As you say, 8mm may be a good compramise .
cheers
rob

 

[ajax1976]

Mines is a 2wd although I did shave the fronts as well which look similar on the old car and are a bit easier to do. It's the same idea tho as you'll see the lip that does the actual centering, I just removed the material down to the lip to get the spacer on.


To be honest if I was doing it again I probably wouldn't bother if it was only for a couple of mm's. I was tied due to my to my big brakes so I had to sort something out and didn't want to buy more spacers.

Not sure if you've already got them but if you're going to be using spacers pick up a couple of these, makes changing a wheel dead easy and accurate.

http://www.ebay.co.uk/itm/ALLOY-WHE...main_3&fits=Car+Make:Audi&hash=item35c1aea3f2

 

[Jimmy TDI]

I would assume that the B7 hubs are the same as the B6?
If so I managed to fit 10mm spacers to the rear of my FWD just by simply removing the cap. I didn't have to make any changes to the front ones at all, they just went straight on.

I bought mine from HERE