FredR

When I went down the path of trying to improve the handling capabilities on my late S4 some 12 or so years ago I was given plenty of good advice by my mentors of the day and immediately ran into camber issues.

For reasons never identified I was able to get the front target camber of minus two degrees on the passenger side but on the driver's side was only able to get minus one degree. With the wide wheels/rubber first time out on the track it was evident this was not enough camber given the scrub pattern on the tyres that ran onto the outboard shoulder. To overcome the camber issue I tried fitting the earlier LCA with a longer throw of some 12mm. This threw the adjustment range by approximately 3 degrees. The camber adjuster has a travel range of 9mm which seems to give an adjustment range of about 2 degrees or so and fitting the longer arm meant that the minimum camber I could get both sides was 3 degrees. I experimented with this and felt it was too much and in the end compromised by fitting the stock arm back on the passenger side as that could cover approx 0 to 2 degrees of camber. With the longer arm on the driver's side I could get minus 2 to minus 4 degrees so basically I was locked into a figure of minus 2 degrees if I wanted the same camber setting both sides.

Some 10 years ago I lost my late S4 in a big accident and then acquired my current 928. Initially I ran more or less stock and after a while needed new rubber so went to check the alignment before fitting such rubber. To my astonishment I had exactly the same problem and same numbers so I fitted the longer arm on the driver side and have not done anything more over the last 10 years or so other than fitting Carl's lower frame brace which I believe reduces the need for front camber due to the additional overturning moment restraint. I woud like to test how much more camber I could reduce but I am stuck in this minus 2 degree syndrome at the moment. Interestingly enough when I launched my thread on the upper control arm ball joint another of our friends said he had a similar experience.

Now I have issues with the suspension in general and need to do something about the upper control arms and quite possibly the lower arms. The options include reverting to the original arm both sides and settling for a camber of minus 1 degree. Ideally I want to arrive at a point where the adjustment range can cover minus 1 to minus 2 degrees both sides but I am stumped as to how I can achieve this. I do not know what is out or why there is a difference of adjusment range side to side. For the driver's side I am wondering whether I can use the longer arm and put some 3mm shims under the upper control arm mount to bring the camber adjustment range in the region of minus 1 degree to minus 3 degrees so I can hit my currently desired value of 1.5 degrees. My concern here being whether moving individual wheels in and/or out relative to other wheels may induce any handling issues- I simply have no idea how critical the position of the front wheel relative to the rear wheel truly is. Instinct tells me it is rather critical but then I do not even know what is out to cause the underlying problem of different camber ranges each side.

I do not think the control arm bushes are causing the problem or if refurbed arms will cure or enhance this difference. My assumption is that a previous owner bent something but what are the chances that two cars with different owner history would have exacty the same misalignment problem?

Any thoughts/suggestions appreciated. If all else fails I will revert with the stock arms and settle for the camber limitation of 1 degree.

Rgds

Fred

GlenL

Do this.

I'm surprised you had the exact same problem on two different cars and I've not heard about this previously. I wouldn't worry about the shims affecting anything negatively. The suspension is adjustable to correct for manufacturing variances and the shims are a further mechanism for that.

My 928 got bent at the track and, despite multiple straightenings, couldn't get close to the same range on the two sides. I installed shims on one side and they're close now in camber but caster is odd. I had a spreadsheet to predict the shims needed and it was wrong, btw.

To make the adjustment easier, I reversed the bolts holding the upper A-arm so the head is inside the engine bay. The alignment shop then added and removed washers while working on the car.

I wanted washers but afterwards they suggested it could have been done using "tabs" instead. Those come in varying thicknesses. They are U-shaped so the bolts wouldn't need to come off and the work would have been quicker.

And I prefer "alignment connoisseur."

FredR

Glen,

If I was to pack the UCA I would indeed have some shims made that could be slotted in and out after loosening the bolts. Good to know someone has gone down this path. At least I currently get the caster I want [5 degrees]

I have wondered why they fasten the bolt on the inboard side and lock it in the arm body. Seems to make an otherwise easy job somewhat difficult. It would be interesting to know what reaction others have to what you did [aka reversing the bolt]. I like the idea assuming it is sound practice. I assume it has a hex head on it? Have not studied this at all.

I have it my mind that it is important to have the rear wheels following the front ones to within a very tight tolerance range as in like within 1mm but maybe I am a bit **** in that regard.

I was truly astonished when my second 928 showed exactly the same characteristic. My 928s have been on three different alignment rigs showing the same characteristic. I cannot even fathom out whether it is random chance or something got slightly bent by a previous owner. By my reckoning something is not where it should be by around 4mm.

mark kibort

lower the car, that will give you much more camber possibilities. (if the car ride height is what i see in your avitar pic). you need 1.7 degrees up front to avoid scrubbing the outer edges of the tire, or a slightly larger tire will also solve this issue (less tire flex and roll over to the edge)
what tires are you running now? (size , profile, compound)
whats your ride height?

dr bob

Alignment commonsewer?

Lowering the car -forces- more camber possibilities, all within normal suspension travel, so is not at all a good idea for street-driven cars.

-----

Fred,

The U-shaped shims that Glen mentions are common on mid-century American and many British cars, readily available at least here in the States.

FredR

Mark,

Ride height was set at the low end of the allowable range, indeed slightly lower if my memory serves me correctly. Current rubber is 265x35x18 up front and 295x30 on the rear. I am due to change front rubber next week and intend to fit a 255x35 section mostly brought about by tyre availability.

Because of the issue I wrote about initially, I am cornered in terms of what I can achieve and at the moment the minimum camber I can achieve on the driver's side is minus 2 degrees [with the longer lower control arm on that side] which I feel is too much camber. With the lower frame brace and going to a slightly narrower section I reckon somewhere between 1.3 and 1.5 will be optimal for my purposes and this is consistent with your 1.7 degrees as doubtless you will be cornering somewhat harder.

Even on the rear I still have issues with camber in that despite the repairs I did to the adjuster pocket and the upper control arm, the minimum I can set is 1.3 degrees at the moment albeit it seems to work very well and is what I intended. I put this down to a permanent set in the rear bushes wherein the rubber is now tired or maybe even rock hard like the front rubber bushes.

Rgds

Fred

Ketchmi

On my last dual purpose 86.5' I was able to get 1.3 degrees on both sides and it was LOW. That seemed to be the maximum for street and the minimum for track use with street tires. That was all the driver's side had, the passenger's side still had some room to go. I will probably use the same settings on my latest 86.5' if I can get it to adjust to them.

FredR

Bob,

Getting a shim made up is no problem at all. It would need to be 4mm thick to get me into the required drop zone assuming the bolts are long enough. I also like the idea of being able to torque the bolting from the wheel arch side assuming there are no technical implications.

Rgds

Fred

FredR

Dave,

That is interesting- another 928 that can get more camber on the passenger side than the driver's side and similar[?] numbers to mine considering you are probably lower than I run.

Rgds

Fred

dr bob

Temptation would be to fab a strip with the bolts tacked in place, so the bolts can't turn as you loosen and tighten the nuts. It would also spread the load a bit. Maybe a similar strip as a spacer for the wheel side of the fenderwall so there's less chance of distorting the fenderwall with overturning force applied to the bolts by the upper control shaft. Use good bolts.

FredR

Bumping this thread-

Just completed replacement of the older type lower arm on the driver's side with the stock lower arm for my MY. I pre-set the alignment to allow me to run some for settlement and then to the alignment shop.

Before doing anything I checked the settings achieved and was astonished at what I saw. Somehow i managed to achieve a maxxed out camber of the driver side of minus 1.7 degrees. Last time I tried this with the stock arm I could only get 1 degree. The only other thing that has changed since those days is the lower ball joint unit I replaced.

I was thus able to set the camber where I now want it at 1.3 degrees, 5 degrees of caster and 0.1 degrees toe in each side. With new Pirelli P Zero tyres a bit narrower than previously now at 255x35x18 and the rears at 285x35x18 [a bit larger diameter than the previous 295x30x18] must say I am very happy with the feel of the ride quality. Previously I was running with 2 degrees front camber for modest track days. Hopefully the reduced camber will improve the braking a bit.

It will be interesting to see how overall cornering ability performs- I am working on the basis that the 928MS lower frame brace will compensate for some of the camber reduction. Hopefully the 255 section will still keep me well entertained in the bends- I always felt I had difficulty finding the limits of the 265's previously up front as the back end could not keep up with the front- even with the Devek bar fully stiff.

Nice to have some options!

Regards

Fred

Carl Fausett

Please post back how your new setup feels to you. I you need more camber than the eccentrics will give you, you can actually adjust the bar to lengthen it a little bit, which will raise camber the same amount on both sides. It also stiffens the suspension. Not intended to replace using the eccentrics to adjust Camber, but certainly you can final-tune the camber angle up or down a wee bit at the frame brace by lengthening or shortening it.

FredR

At the moment I am in good shape in that I can go up to -1.7 degrees whereas previously with one long arm and one regular arm I could only set camber at -minus 2 degrees- one side being maxxed the other at minimum adjustment!

Before I fitted your lower brace that seemed to work fine but after fitment I felt there was no need for that much camber judging by the scrub pattern on the tread that was then short of where the tread runs into the tyre shoulder.

Interesting piece of lateral thinking about using the brace as a jacking bolt for small increments.