ckkrause

I have an '87 951. I recently changed out my 23mm original T-bars for 28mm and went with 250 lb springs in the front. I then adjusted ride height using the eccentric, so that front and rear were the same left to right...

I then took the car into get an alignment done and, since this is a DE car, asked for -2.5 camber/stock caster/stock toe in the front and -1.5 camber/stock toe in the back. They were able to get the front right on and the right rear right on, but the left rear wouldn't budge from -2.5 camber/ -0.33 toe!!!!! Alignment was fine before the torsion bar change... Any thoughts on what might be the issue with the left rear alignment issue?!?!?

Thanks for looking!

-CKKrause

MPD47

Hmmm, how are the bushings for your torsion assymbly?

Skip Wolfe

How familiar is the shop with Porsche rear suspension? I had Goober at a local shop try to set my front alignment only and the fact that I had camper plates threw him all off and he made a couple "I can't statements".

On a side note I would recommend going with 300-350# springs in the front with the 28 mm tbars. What you find with the 250# springs on the track with R-comp tires is that your are riding your bump stops. When your on the stops the car will push, otherwise it will have a tendency to be loose. I started with 300# springs and 29 mm tbars and ended up running 400# springs and like it - probably could go up to 450# but then I would be overwhelming my Konis even more than I already am. Rough rule of thumb is the front rate should 1.5 times the rear.

Skip Wolfe

While this is important it should affect the alignment. The alignment eccentrics are essentially independent of the spring plate blade - meaning when you adjust them the spring plate stays stationary and the wheel assembly moves.

MPD47

Skip, we ran into a problem with the bushings on my car last year which we believe was part of the problem keeping my car's rear from being able to toe in.

ckkrause

Thanks for the feedback!

With respect to the bushings, I did not change them, (although they're not 100% round), and the rear left aligned fine before I did the Torsion bars...

With respect to ride height change, I used the method you've shown in your diagram...However, I made no attempt to do anything other than bolt up the mounting bolts...I can't remember if they bolt into sloted holes or not? Also, is it possible that the rear is too low at about 12.5 inches from the wheel center to fender edge?


Thanks!

-CKKrause

Skip Wolfe

The alignment bolts have eccentric lobes on the back side of the nut head that fit into the holes in the trailing blade. If you took those bolts out sometimes they are tough to make sure the lobes are seated in the holes. If they are not seated the bolt will spin but the alignment won't change.

ehall

No Flames!...but did you reindex the new bars? Are they reindexed exactly the same all around? (L and R)?

ckkrause

Yes, I set them at the same angle...as you know, it is an educated guess as to what that angle is, but I got lucky and only had to do it once! I did set the 36 mm adjustment nut in the middle and had to make small, (6-8 mm) adjustments to each side... By the way, I used Chuck Moreland's "dropping one side at time" procedure and it was relatively easy compared to what I had expected. Too bad it's not like changing out qa torsion bar in a 911....

-Happy New Year!

-CKKrause