ajw45

Short story, had the car aligned before it's first track day, car drove great, had a great day, but noticed a slight pulling to left on the way home. After a hundred miles to make sure I wasn't crazy, took the car for another alignment and found the alignment was off mostly on the passenger side. Weird thing is to get the alignment right, they added control arm shims only to the right side. So, now the alignment specs look good but shims were added to the front and rear on the passenger side only. Anyone else have this happen when they had their car aligned? Could this be symptomatic of a different issue?

Fwiw, two different shops did the prepaid and post alignments, both reputable Porsche independents. I would have gone back to the first for diagnosis but I'm out of town with the car...

MarcD147

did you check the tires? wear? pressures?

did you check the sway bar? (not sure if this could really cause this...)

ajw45

Yup, tire pressures are good. Never had MPSC2 tires before so I experimented with pressures throughout the day and took temperature readings across the tread for future reference. Under the car now, sways look okay.....

ExMB

Normal method would be equal shims on either side and then fine tune up top (front) and the excentric (rear).

jphughan

There are shims on one side of each axle for the headlamp auto-leveling function, so that could explain only putting shims on the other side, but ExMB is right that typically the top mount would be used for fine-tuning, and it offers more than enough range to offset whatever impact the headlamp auto-leveling shim would have. I think those are only 1-2mm. Maybe your shop wanted to keep the top mounts as outboard as possible to maximize track width?

The alignment I got was actually the first one where dead center on the steering wheel really was straight ahead; for every other car I've driven even right after an alignment, the steering wheel always has to be tilted just a few degrees to one side to run true, which I always attributed to slop in the steering rack or the fact that setting toe is never absolutely perfect. But this alignment also took a lot longer than the other ones too.

ajw45

Thanks for the feedback guys. Considering it was consistently off on both front and rear and just on one side I'm starting to think maybe the alignment machine could have been wonky....

My first alignment was awesome...

stingray84

FWIW, I have 2mm extra shim on one side versus another. Shop owner told me it's common that GT4 alignment is not exactly symmetric in stock form.

mrd_spy

rubbish.

Bill Lehman

If the car felt good on the track and later on the way home you noticed a "pull", I would take a good look at camber and toe on the rear axle. Both are set with an eccentric screw which has been known to slip under track conditions. I had a camber adjustment fail and the resultant camber caused enough toe in the rear that I had to hold the steering wheel well off center to drive straight and got a PSM failure warning on the dash. There can be slight alignment differences when the car is delivered and these might change a little more after springs settle but I've never seen a situation where you would shim one side of the LCA and not the other. You might look for a better shop.