alignment

[shifty]

On Gordon Glasgow's recommendation I got an alignment done at Tru-Line Frame and Wheel here in Seattle. Very professional shop, there were Maseratis and Ferraris, etc. everywhere.

Here are Gordon's recommended specs:

camber: -1 degree
caster: 2.5 - 3 degrees +
toe-in: 1/16 - 1/8"

Here's what my car went in with:

camber: left +.73, right +.36
caster: left .89, right 1.6
toe-in: left 11.6mm, right -5mm

And after:

camber: left -1.21, right -1.12
caster: left 3.45, right 3.46
toe-in left 1mm, right 1mm

WOW! Big difference in handling. Can't wait to flog it and really feel the difference.

They had to replace the upper control arm bolts with longer ones to meet the specs.

[Linda]

I'm going to try to get an alignment soon I hope on my car, and found this post. Should there be this small variation in the final alignment as in the case posted here? A good alignment shop would figure this out or would a "computerized" alignment like many tire shops do be OK?
Like most things for the Roadster I think there is "more to it" than I know about so hope someone can help enlighten me.
Thanks as always,

Linda
68 1600

[Linda]

Are these still the preferred alignment specs? What is everyone using?
Linda

[bobd]

The guy that did my original alignment retired and none of the places with computer alignment machines wanted to touch it. The specs weren't in their computers & one guy told me he had no clue how to adjust, but he did give me a print out of the alignment. Another guy had a clue, but his clue told him it was too much work.

So I bought a caster/camber gauge and some toe plates and went to town. My first attempt was in the ball park, it drove straight and did not pull or drift.

A couple of months later I installed JT's front shocks and gave the alignment another try. I made an Excel spread sheet to organize the measurements and keep track of the spacer measurements - this was way better than my previous scribbling.

This is what I wound up with (both sides equal):

Caster - +1 degree
Camber - +3/4 degree
Toe in - 1/16"

Upper A arm shims:
Left Front 0 Rear 1/4"
Right Front 0 Rear 1/16"

I am happy with the handling and tracking at these settings using comp front springs and sway bar.

Done on the floor with garbage bags for turn plates and a floor jack.

Combining the specs for stock, spirited, and racing we get a range:
Caster - +1 ~ +2 degrees
Camber - +1 ~ -2 1/2 degrees
Toe in - 1/16 ~ 1/8"

[fj20spl311]

I think you want more than +3/4 degree caster.
Caster is what gives straight line stability and return to center steering. It also compensates for camber loss from the inclined steering angle aka King pin angle. The KPA for the roadster is 8 degrees, race setting from 50% to 100% of KPA for caster.

[bobd]

Caster is +1 degree. I'm going by the specs in the wiki:



Should I not use these specs?

[fj20spl311]

Caster is a trade off between how much steering effort and much self centering.

[bikermike]

A related past discussion:
http://www.311s.org/phpBB3/viewtopic.ph ... nt#p182116

[redroadster]

I built a alignment system, memicing a popular 70s system, using those dollar store lasers
You need very free turntables , ( it would not do a mini truck , to stiff) havent used it lately ,but still have it
usually you want a quarter more caster on the R Side to correct road crown , caster is a turning force

[fj20spl311]

original specs. are for "Bias Ply Tire"