cluskera

Hi, I have new shocks (koni fsd) and replaced the suspension arms. I got the geometry redone. Car handles well, nothing untoward going on but I have noticed it seems to sit maybe one and a half cm lower on right side.

When i measure from the edge of the strut tower to the spring "platform" on the shock the right side is indeed about this amount less perhaps suggesting the spring is compressed more.

the springs at rear have 3 white dots (option code 033).

The direction that the right and left springs are oriented is different on each side i.e. I would have to rotate one 180 degrees to look identical while looking under the car.

First question is does that matter ?

second question is can spring fatigue occur and does my measurement suggest that may be the culprit?

thank you in advance

I've measured from edge of strut tower to this ledge on the shock and it differs left and right.

OverBoosted28

Corner balanced? If so, car most likely will not sit exact, at each corner, and is acceptable/expected, to a point.

IainM

Does 180lbs in drivers seat fix it?

nine9six

Yes, spring orientation makes an "appearance" difference, if the align n corner balance shop is paying attention to detail; as you have noticed.

As IainM hinted; was the corner balancing performed with you, or sandbags representing your weight (not that you weigh 180 lbs) in the drivers seat? If so, an empty drivers seat side, should tend to sit a tad higher for this reason.

NC TRACKRAT

How can you corner balance with KONI FSD's?

squidge

Good catch -- you can't. The perches are non-adjustable.

NC TRACKRAT

Now that we have that out of the way, may I suggest that you measure and compare suspension height on each side according to the manual, namely from level ground up to the flat boss on the underside of the rear lower suspension arm. As IainM implies, the measurement should be taken with a full tank and appropriate weight in the driver's seat.

mpruden

I think there's some bad info in this thread.

First, pretty sure you can do a coarse adjustment of ride height with Koni FSDs on the rear by using a different size spacer in the rear mount. You'll see these spacers in the PET with 3mm, 5.5mm, and 8mm thicknesses. It's not uncommon for manufacturers to offer various thicknesses of spacers for this very purpose. I don't think you'll be able to close a 15mm gap, but you should be able to cut that in half.

Second, you absolutely can adjust corner weight with the FSDs. That's why the fronts have so much adjustability of the spring perch.

cluskera

Thanks guys. I hate to say it's the driver's side that's lower, without me in it!

mpruden - interesting. If you read this, does that spacer go on the perch in my picture?

I'll take them both out anyway and examine the springs more carefully

mpruden

The spacer is part of the upper strut mount. The mount is actually 3 different pieces that are sandwiched together.

You're interested in the center ring that's noted with the arrow.



The part numbers are 993-333-511-00 (3mm), 993-333-511-01 (5.5mm), or 993-333-511-02 (8mm).

JB 911

Interesting info mpruden. Any idea which spacer came on the US 993's?

mpruden

Not sure, and I believe it would have depended on the number of dots on the springs as it left the factory. I've seen both the 3mm (above) and the 5.5mm on cars. Not sure I've ever seen an 8mm. At least the 5.5mm are easy to spot because they are made from white plastic instead of black.

Here's what Porsche has to say on the topic:

Select the intermediate section in accordance with the tolerance group of the coil spring (color coding/colored lines on spring).
1 line = 8.0 mm intermediate section
2 lines = 5.5 mm intermediate section
3 lines = 3.0 mm intermediate section

Check out this excellent thread from George with all the details.

NC TRACKRAT

mpruden, I stand corrected. Could be advanced age kicking in, but I do recall now, when installing the M033 on our '95, seeing the spacers on the PET. Fortunately, after installation and alignment, the car was well within spec w/o changing the spacers.

cluskera

great info thank you. The only question I have is surely you have same spacer on each side - or are you suggesting people offset to remove left/right spring variation ?

mpruden

I would use it to offset left/right spring variation but only as a last resort. Assuming you have no other mechanical problem, I would:

1) Fill the fuel and windshield washer tanks
2) Measure ride height from the factory measuring points to a reasonably level floor. Do not measure from the wheel well, roof, or other point. Only measure from the factory locations.
3) Adjust fronts as well to make sure they are within spec. You should be within 5mm left to right and 10mm front to back. For the front to back, you calculate the delta by adding the variances between your target. That is, if you are trying hit ROW M030, your target is 144 front, 127 rear. If your actual is 140 front, 129 rear then you are -4 front and +2 rear or at 6mm delta, comfortably within spec.
4) If you cannot get the l/r rear within spec after doing the above, then I'd adjust the spacers.

Disclaimer - I'm not a pro mechanic, so take all of this as one random Internet guy's opinion.