re-indexing rear torsion bars question...

[vash]

ok, i did it again. i re-indexed the rears...AGAIN! my CB and alignment guy wants me to get it closer. right now, i am 25.5 in front, and i want 25 in the back. i am touching 26 on the drivers, and 25.75 in the pass side. using ferch's "hooke's law made easy and convienent" calculator. i knew the target angle. i swear i hit it.

i know there are two sweet spots on the rear springplates. you hit one...miss. try the other one, miss.. then you pull the inner splines and try to rotate one tic. then look for the two sweet spots again on the outer splines. can i get .5 degree adjustment with the splines? doesnt seem possible. i seem to "feel" that there are only 2 sweet spots on the inner, and 2 sweet spots on the outer splines. if you move them over and over again, am i not just repeating the four possible angles?

brandon krause, the bay area's goto guy for CB and alignment wants me to bring him my car with 25.5 in the fronts, (check!) and 25 on the rear pass, and 25.25 on the rear drivers side. and have the springplates set in the middle. i will do my car for the third time. on the bright side, i am getting fast.

sorry no photos. this job is one of the messier ones. i cant touch a camera.

[Eagledriver]

Why on earth do you have adjustable spring plates if you are not going to use them? You are making this way to hard on yourself.

-Andy

[KFC911]

If he's taking it in for a CB, then having the adjustable spring plates at their mid points would give the shop a better chance to adjust (up or down) w/o having to reindex the t-bars. I know I wouldn't want to pay shop rates for that .

[boyt911sc]

Originally Posted by vash

........0.5 degree adjustment with the splines? .

The rear torsion bars have 40/44 splines (inside/outside) on them.

Inner splines (40) = 9.00°
Outer splines (44) = 8.18°

Differential Angle = 0.82° (This is the least differential angle you could obtain between adjustments using the splines only).

Tony

[rnln]

sorry vash for jumpping in your thread.

Tony,
Could I ask what is the heigh change (let say at the fenders) correlated to each inner/outer spline?

Thanks.

Originally Posted by boyt911sc

The rear torsion bars have 40/44 splines (inside/outside) on them.

Inner splines (40) = 9.00°
Outer splines (44) = 8.18°

Differential Angle = 0.82° (This is the least differential angle you could obtain between adjustments using the splines only).

Tony

[vash]

rrln; depends on the torsion bar size.

.82? thanks! all i need is similiar triangles, andi could calc, the length at the fender.

[rnln]

assume everything is stock.

Originally Posted by vash

rrln; depends on the torsion bar size.

.82? thanks! all i need is similiar triangles, andi could calc, the length at the fender.

[jester911]

Great timing on this thread. I just put my car down on the wheels after upgrading Tbars and bushings. I am way low in the back and have got to re-index them. What a pain.

[ttweed]

Originally Posted by rnln

Could I ask what is the heigh change (let say at the fenders) correlated to each inner/outer spline?

The height change at the fenders is ~6.5mm for the .82 degree (50 min.) minimum adjustment, according to BA.

TT

[JFairman]

For small changes move the inner spline one notch one way, and the outer spline one notch the opposite direction.

One inner spline moves 9 degrees.
One outer spline moves 8.18 degrees.

Just as an example, I moved mine 4 splines on the inner end and 3 splines the opposite direction on the outer end to get them right.

[niner11]

Vash....you're going to make this a whole lot easier for me when I go through this if you take a few pics :-)

[vash]

niner, i wish i could. i am doing this gig solo. you will find out sooner or later that this is the most greasy job you can do. i am coated afterwards. no way i grab a camera during the project. sorry. my wife wont volunteer either.

thanks everyone. i hate this project.

[angelny911]

subscribe seem like a good thread !! thanks

[jester911]

I will try to take a few pics today when I do the other side. It is always more fun the 2nd and 3rd time around.

[vash]

FINALLY!!! my corner balance guy had a track accident and took a week off. i finally got all ER polybronze bushings perfectly installed, my ride height perfect...car is aligned. i had to wait till it was corner balanced and aligned before driving it around. it was agony waiting to determine if my hard work will be rewarded. saturday, i took it to an AX. my car jams! i bested two friends that usually hand me the spanking. no more steering wheel vibration at 75mph. (probably the new ball joints). i love my car again. track time scheduled next month. Chuck's elephant polybronze bushings are the way to go. in hindsight, i say the install was a 7 out of 10 in difficulty.

cliff