I will be Swapping my Boge shocks for a Bilstein/Eibach setup on my 86.5 when the parts arrive tomorrow. All four corners are off the car and taken apart/cleaned in preparation. My question is where exactly should i initially set the adjustment nuts for the spring perches to get me in the ballpark of the factory ride height? Also ..... how many turns on the adjuster nut are equal to how many millimeters adjustment to the ride height? I need this info for both the front and rear.

Ben Burris

86.5 Indischrot AT #1459

 

Ben when I installed mine I measured the setting on the old shocks and set the new ones at that. I still needed to reset them lower but at least it didn't look like a 4x4.

 

Thank you Shane, I am thinking my setting from the old ones might be OK for the fronts which were still in pretty good shape but my rears had been sagging pretty badly in the last few years. With that in mind the previous setting on the rears may make the car look like a monster truck with the fresh springs. Anyway, i am just trying to get it close so i am not jacking around with it for hours on end trying to dial it in. I guess i could start out at the paint markings i made for the settings from a couple of years ago before the rear springs started to sag more noticabley.

 

Ben..........check out Tonys web site for the initial results he got for the same spring/shock combo: http://members.rennlist.com/v1uhoh/fcoinstall.htm.

The WSM height adjustment 180 +/-20mm front and 173 +/- 10mm Rear.........probably more important to get the side to side height the same and then concentrate on the front and rear ranges. I'm going for the same setup and would be interested in your views of the new suspension.

 

Actually, the ride height spec is

Front 190 -20mm

Rear 173 +/- 10mm

 

Will...........my 9 vol. WSM page "44-05 wheel alignment measurung data" specs the values I posted. These same specs are repeated on pages 44-2b and 44-3.

Are there different specs on another page for older cars?

 

As far as height adjustment goes, measure the thread pitch on the new adjusters: it will most likely be in the range of ~1.5mm/turn. Regardless, this value will be close to the elevation change per adjuster turn, as the spring compression is not being changed - only the shock extension changes. The suspension geometry slightly alters the height value per turn, but remains effectively linear.

 

Ben you will find that the Eibach springs are shorter than the stock springs since they are stronger. They are designed to lower the car somewhat but the adjustment of the nut on the threaded Bilstein shock should allow you to make any needed adjustments. The nuts are easy to turn when the shocks are new. Remember the front will need several miles and hard stops to settle especially if you have tightened the lower a-arm collars with the arms at full droop.

 

Thanks Jim, the Manuals do mention leaving the collars loose with two threads showing, so should i wait to snug them down until the new shocks/springs are supporting the weight of the car? I.E. back on the ground? I am also wondering how much the new ride height will affect my alignment, i guess i should have checked where i was at. I think the front springs were still pretty healthy but the rears were definitely sagging, the top third of the tire sidewall was covered by the fender. I think i should remove my Fikse wheels and put on the old flat dishes and worn tires just in case my alignment is way off the marki don't want to wearing my new tires. Once the height is adjusted and dialed then I can take it to be aligned with the Fikses back on the car. Would that be a appropriate approach? I still have a few days, i am doing the motor mounts at this time as well.

Ben

 

Your alignment is going to be off so the old wheels and tires make sense as you work on the ride height adjustment. And yes it is best to drop the the car down on the wheels before tightening the collars.

 

Ben,
Jim raises an excellent point re. the torquing of the lower arm bolts: they are 'easily' reached when the car is lowered. If 'mo easy is needed, slide a couple of planks under each front tire prior to lowering the car = better access to the bolts.
The first time in ( too long ago to be embarrased about), I did the reverse - and there, pointed at the moon, was my 928 a full 8" above the front tires.

 

Thank you for the advice. The shocks and springs came today and i have already bolted the rear set in place. The motor mounts are here also, so i will wait till they are done to finish the front set.