mopar suspension questions

[dusterbd13]

ok, now ive got to get the duster realigned by a COMPETENT shop. the last shop told me i need adjustable upper control arms to get the alignment specs i want, which are 1 degree negative camber, 3 degrees positive caster. the car is currently set up with:
addco 1 1/8 front sway bar, boxed lower control arms, 73 duster spindles and steering linkage, cop car diplomat box, adjustable strut rods, poly bushings everywhere except lower control arms, KYB shocks, 340 duster rear leaves, 7/8 rear sway bar, subframe connectors.
the car has a fiberglass hood, aluminum radiator, aluminum heads, intake, water pump, relocated battery to the trunk. currently wearing 15X7 wheels wrapped in 235/60/15 front and 275/60/15 rear. ride height is set to where it looks right, with a slight rake.

the problem is the car currently drives worse than the wore out stock suspension i had under my V8 dakota. it has a felling of push/tipsy when going into a turn, and the wheel does not return to center. feels slightly unstable at speed. i think this is in the alignment specs, which are currently where the last incompetent shop that damaged the car put them. i believe it is 0 camber, >1 degree caster, zero toe. the "tech" that did this "alignment" made the strut rods longer (causing wheel to hot fender, damaging paint) which i believe on this suspension makes for negative caster, not positive. am i correct? also, will i be able to get these specs out of this front end with the parts i currently have, or will i need the tubular upper control arms like that guy said?

hpe i gave enough information for y'all to advise me.
so let me know what you think.
Michael

[MrQuick]

You are correct. All those readings with the tall tire will give you that feel.

You can use the stock arms but you will have to modify the upper arm adjuster eccentrics to get the measurments you want. You can make them or weld/remove material on your stock ones. Then modify your eccentric retainers.

[dannyho]

have you looked into getting the moog "helper" bushings. they have an offset hole for the upper a-arms allowing you to add plenty of caster.

[dusterbd13]

i thought about the helper bushings, but i really like poly, and theyre rubber.
as far as mr. quicks idea, it definately has my interest peaked. can you provide more infor on how to do what youre talking about?
Michael

[High Plains Mopars]

ok, now ive got to get the duster realigned by a COMPETENT shop.

i think this is in the alignment specs, which are currently where the last incompetent shop that damaged the car put them.

I'm confused. You had the car realigned by a new shop, but you then state the specs are where the previous, incompetent shop set them. If you have a new shop, why didn't they put your new specs on?

3 degrees positive caster should be obtainable with stock control arms without anything special, provided everything in the subframe is straight and square. To go out beyond 3-4 degrees would require the offset bushings or tubular adjustable arms.

Even with a tall, 60 series tires, you should handle decently if everything is set correctly. When you say it feels like it is a push/tipsy, does that mean that it doesn't turn in as quickley as you'd like or it turns in so quickly it feels like your rear is coming around? Push is the front end refusing to turn. Tipsy sounds like loose, which is the back end coming around too quick.

What size front torsion bars are you running?

The mod MrQuick is talking about sounds like taking the oblong adjusters that hold hte control arms on and trimming/adding material to provide them with additional offset over stock. Sounds like a lot of work for minimal gain, but if your determined to retain the stock arms, stock look, and poly bushings, it would work. Easiest fix is to use offset bushings. Best fix is to use tubular arms.

Yes, your correct on the struts. Making them longer will increaase the negative caster.

[dusterbd13]

i know the car needs realigned, but i have not found a local shop i am willing to let touch it after the last guys messed it up. so thats why its still at the last alignment specs.
as far as the push/tipsy, it is understeer coupled with feeling like i have a lot of uncontrolled chassis movement. like it almost lurches into the push. better way to descibe it is it feels like the chassis is taking its sweet time to respond to the steering wheel inputs, and has a moment of funky feeling transition before going to push.

t-bars are the big block .89 units.
the front tires are like 25.5 inches tall overall, the rears are 28. it doesnt seem that tall to me, but i also havent driven a car on 15's in years.

hope that helps to clear it up.

do these specs seem in line for a fun, capable handling driver? wont be doing any open tracking or autocrossing with it (well, not yet at least). just having fun on the weekends when i drive it around my rural county.

Michael

[High Plains Mopars]

Your specs should be easy to achieve and are exactly what I'd expect to see under a street car. If the previous shop couldn't get you three degrees of caster, it is probably because they lengthened the strut rods instead of shortening them. Turn back the struts a few turns to help with this. If you can't find a shop that knows how to do mopars, look for one who can do later model mustangs. Some of these use adjustable struts also, and they are similar in function to the mopar struts. This caster issue is why it feels unstable at speed. Your Dak likely has 6 degrees of caster compared to your duster at 1 degree.

While you checking and measuring things, It might also be worth checking your tie rods to make sure they are equal length too. Adjusting only one tie rod instead of both is another way cheap shops do work quickly.

When you get ready for anew alignment, you might also shoot for 1/16 to 3/32 toe in. Zero toe and toe out also contribute to a very twitching and uneasy feeling if you are unfamiliar with it.

While it doesn't contribute to an oversteer situation, your rear sway bar also seems kind of large for what is an otherwise close to stock set up. This can also contribute to the funky feeling you are having during transition. Try disconnecting one side of it and driving around like that for a while and see how it feels. Until you get up over 1" in torsion bar size, you aren't going to need that big of a rear sway bar. If you really want a rear bar, you might try to scrounge up a more stock sized 1/2 or 5/8 bar.