front suspension geometry

[71dusterdan]

is there anything to gain in changing the front to back angle of a spindle? the reason i ask my upper control arms have heim joints so they didnt come with spacers. i was told to make som out of heavy gauge tube or washers acting as shims. so my thought is to use the washers, and then i could change there position front to back, which would then in turn either lay the spindles down or stand them up a degree or two. with all the other adjustable crap in my front end i am probably gonna be testing your average alignment shop flunkie. is there anything to be gained with this kind of flexibility. it will be a while before i can drive good enough to utilize that kind of tuning, but everyone has to learn and practise. thanks. Dan

[Derek69SS]

That's called caster.

Generally speaking, more positive (layed back) makes the car more stable at speed, but you only want to go no more than about 6*+

Less positive caster (more straight up) makes steering effort easier, but less stable.

You don't want them to lean forward.

5*+ is about ideal for a mild performance street car.

[Bjkadron]

What Kind of Control arms do you have? If they are adjustable you can just keep them positioned in the middle and set your alignment with them.

[Hotchkis]

is there anything to gain in changing the front to back angle of a spindle? the reason i ask my upper control arms have heim joints so they didnt come with spacers. i was told to make som out of heavy gauge tube or washers acting as shims. so my thought is to use the washers, and then i could change there position front to back, which would then in turn either lay the spindles down or stand them up a degree or two. with all the other adjustable crap in my front end i am probably gonna be testing your average alignment shop flunkie. is there anything to be gained with this kind of flexibility. it will be a while before i can drive good enough to utilize that kind of tuning, but everyone has to learn and practise. thanks. Dan

Hi Dan -

If I understand this correctly, you have upper control arms with heim joints, but they didn’t provide spacers to properly shim-fit into the clevis mounts on the body? By making your own shims, you have the opportunity to gain more positive caster, which is good. Shimming the arms toward the rear will increase positive caster. Check the a-arm clearance throughout it’s travel when shifting the mounting points.

You seem to have this project well underway, but for your next car, our a-arms do come with spacers. ;o) We currently have the early 67-72 “small ball joint” arms. We are working on the later models arms now, and we have B and E Body Mopars available.