jury_ca

I recently had my C4S 4 wheel aligned by the Porsche dealer in Seattle after replacing the front upper strut mounts. One of the remarks that came back on the invoice was th at one of the sides was right at the limit of spec at its maximum adjustment setting. The car has not been involved in any accidents of any kind. What are methods of recourse should the alignment drift past spec and past the adjustment point?

jumper5836

Is the car lowered, usually that will give you more negative camber and when bringing it back to spec will make it reach the maximum adjustment setting. My car is really low and the rear and can't even get it to spec (-2.6 at max adjustment).

Ubermensch

What alignment measurement are we talking about? Caster, Camber, or Toe?

Ptech1

More info would help...

jury_ca

The car is slightly lower as it has the ROW M030 suspension on it. Based on the alignment report, the camber on the front right is at spec at -0.3 and the caster is at spec on the front left at 7.5. All other values are within the specified range.

Ubermensch

I assume the numbers listed are in degrees, but you might want to confirm. Here are the actual specs:

http://www.renntech.org/forums/topic...lignment+specs

Your caster is close to the limit, but within spec. Is there difference between right and left caster? It's non-adjustable, so if you have a difference there's a possibility of a bent component.

S.

Macster

There doesn't appear to be agreement on this but it may be possible there is some caster adjustment available by careful movement of the top of the strut. The adjustment comes courtesy of the room the holes through which the top of the strut fasteners protrude have.

When the OP had the upper strut mounts renewed the new ones might have been installed at a slightly different position and this can account for a slight difference in caster.

Now some say there is no room for any adjustment. I have not tried this with either of my Porsches but with other makes in the past it was possible to get some caster adjustment. Not much but often not much is needed to get them both the same or to at least reduce the difference. A difference in caster can cause a car to want to pull in one direction or the other.

jury_ca

It is in degrees. Caster Left/Right are even at 7.5 deg. Perhaps it is in reference to my front right camber which is at -0.3 deg and my front left is at 0 deg?

Macster

Camber difference of 0.3 degs is very close to the 0.333 degs max difference allowed between the left and right wheels.

IIRC the car in this case is lowered therefore there may not be enough adjustment to bring the car alignment closer to ideal.

Now there is some leeway. For instance there can be for the Boxster -- which I just happen to have the numbers for in front of me -- and for ROW suspension: +5' +/- 30' (USA).

FYI, non-USA ROW the numbers are: -15' +/- 30').

IAC, perhaps the other side can be adjusted to have more negative camber and thus reduce the difference between the two sides?

The alignment shop I think should have pointed this out to you and offered you the opportunity to choose.

Or with the ROW suspension you may need to consider installing other suspension components that allow more adjustment so the shop can bring the alignment of both sides into closer agreement.

Ubermensch

Your caster is at the limit, but it's within spec and the same on both sides. I wouldn't think twice about it. Your camber is a little different on the two sides, but again, the difference fairly minor so I wouldn't be too worried. It would be nice to get the camber even on both sides if you're a perfectionist...like most P-car owners. Also, 0 degrees of camber is very vertical...Most people prefer a little negative camber for better handling.