205 wheel alignment data

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neilc

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I recently had a wheel alignment done on my 205 gti after fitting kw coilovers and bm baker adjustible top mounts. When I set up the camber so it was equal on both sides I noted that on the LHS the strut was at maximum while the RHS was at the midway point.
SAI Steering Axis Inclination on the LHS is 55' RHS is 12 degrees 45'. The lhs has had a hit at some stage in the past I have replaced the lower control arm in the time I have had the car.
Has anyone got any suggestions how I can fix the problem?
 
Here is the Alignment report.
 

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Wow. A difference of 12 degrees left to right?!

I would suggest you need to check your underframe and take it from there.

Looking at the toe it seems the hit displaced the lower arm quite seriously. Whether this is in the chassis, the underframe or both is up to you to discover.

Not sure how to read the positive/negative toe values. Toe should have equal values (same sign) left to right. Positive means in (wheels converging at the front), negative means out. Your wheels seem to point one in and one out?!

Absolute value is the same apparently after adjustment but why is one negative one positive?

Normally should be both negative but I would expect lower values (1 or 1.5degrees). Then again, I am not sure those are degrees on your sheet because at 24degrees (positive or negative) your car wouldn't move. Perhaps some unit invented by the garage? Can you ask them?
 
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Thanks for the feedback I will ask them about the toe values. I will check the subframe next weekend. Is there any free movement where the bolts go though the subframe to do some correction?
 
Caster - Wind on as much as possible. Why did they start approx. +4 but finish up different?

Camber - the extra caster will add camber on turn in, thus -2 ish is fine if occasional track car, but if a track car on semi slicks, then -3+.

Toe - I work in mm. If it's a track only car, set it at 4mm toe out, total. Occasional track day, 2mm toe out, total. Never on the track, zero.

No idea about the SAI. Mine is weird too but goes around corners better than most. I've since increased the caster to +6, but you won't get that without serious mods and extra cooled PAS.
 

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Thanks Peter I will see if I can get toe in mm. It is interesting that your SAI is unequal as well according to research I have made SAI should be equal. My problem is that I am at maximum camber on LHS but can get more on RHS
 
I don't know if you can adjust the position of the subframe, but I would guess apart from jiggling about a bit within normal tolerances there shouldn't really be any movement. Reason being the subframe has to locate the suspension and steering fairly accurately in a designed position relative to the chassis.

All adjustments are done at the points where they were designed to be done. If the subframe allowed moving about, you would throw off everything when messing with it in a bad way (I mean you would change so many things at once, there would probably be no way to recover).

SAI I think in the case of a car with no adjustment is locked in by design for a reason. You have added this adjustment feature but I do not think it is necessary for road cars. I also do not think SAI adjustment is there to compensate for problems elsewhere. As Peter suggested, SAI will impact your camber gain on cornering (and so will caster). I wouldn't play with either unless I had a special purpose in mind, some serious suspension specialist help and a seriously tricked out workshop.

SAI will also change other settings like toe so you need to be aware of the order of adjustments or corrections you need to make after adjusting something like that.

My guess is that most places are set up to measure things like that (normally non-adjustable on cars) to give people and/or the technician some idea of the state of the car and highlight possible problems (what would you do if the SAI were outside factory spec left to right and was not adjustable? Not much you could do, right? But you would know there is some problem somewhere).
 
Thanks for the feedback from my perspective as I use the car for Sprints I would like to optimise the handling of the car. I would be keen on working out where the problem lies first.
 
adjustable wishbones will allow for some adjustment surely?
 
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