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I need some help. I have a factory manual and an owners manual for my 1986 Trans Am with WS6 suspension. Nowhere can I find settings for the suspension listed. Anyway, I am seeking advice from experts due to one change I made in the stock WS6 suspension. The front end has been completely rebuilt so needs a complete alignment. I have replaced the lower arm bushings with Polyurethane. New Delco lower ball joint. New Delco struts with new tower bearings. new wheel bearings and seals. New stock calipers. Vented and slotted standard size discs. New Hotchkiss lowering springs. (about 1"). all steering rods replaced with idler arm.. sway bar replaced bushings and end links complete all in polyurethane. Wheels are the factory 16". Tires are the standard factory size 245's. So basically the deviations are Polyurethane everywhere and the springs, with the rest all OEM. I drive the car mostly in regular street traffic in Los Angeles, however I do drive a little aggressive when possible. Can someone tell me what the best settings would be given my changes. Thanks
This chart (origin unknown) has made the rounds here.
I've got my camber at -1°. It's made a huge difference is the life of the tire. I used to burn up the outside edge in a season or two of driving when I was using the recommended factory specs.
Last edited by skinny z; Mar 20, 2022 at 11:33 AM.
Irrelevant. Common and ordinary, and not material to the discussion at hand. Since cars came out with those giant STICKERZZZ!!!!! on em, nothing but a buzzword. In any case, it doesn't tell anything about "suspension", as such; only, spring rate (which you've changed) and strut/shock properties (which you've changed), so strictly speaking, it no longer applies. No need to beat us over the head about it.
None of the rest of that is too terribly material to optimum alignment either, except for the info about where you will be driving it and what properties are most important to you. Those 2 things are CRITICAL to such a recommendation. I'm glad you put that in there because those are the things that are REALLY important, and saved me the trouble of asking.
Not sure what struts AC/Delco is re-boxing and putting their name on these days. My guess would be Gabriel or Monroe, if it's even a US source. They're CERTAINLY NOT "the same" as the originals, since NO replacements ever are, and in 2022 AC/Delco is just a brand name on a box and not really a "manufacturer" of most of what they sell. In any case, not IMO a good choice; you would have done better with something like KYB, or for REALLY premium results, $$$Koni$$$. Butt, even new that crap, is about 10,000 times better than old wore-out original. Just, don't be too surprised to find that they're limp and floppy again within a few thousand miles, or too reluctant to re-replace them when that happens.
That said though, most streets in LA that I've ever driven on when I lived out that way or when I visit nowadays, are fairly flat (no "crown" like you often find in really rainy places like Houston or New Orleans), therefore the settings on the 2 sides will want to be about the same (no need to make the car "tend to" track toward the left).
I'd suggest:
Caster +4 - 4½° (top of strut moved rearwards as far as it will go)
Camber –½ - 1° (tires leaned very slightly inward at the top)
Toe: In 1/32 - 1/16" (tires pointed slightly together at the front)
If the car tends to drift towards the curb, you can offset these settings slightly; you would use slightly (like ½° or less) less positive caster and/or negative camber on the left, compared to the right. You shouldn't need much of this though, if any at all, around the LA area.
Be aware that these settings tend toward making the tire rub the fender well; particularly at the rear, right in front of the lower door hinge, and when the steering is turned that direction and the suspension is in "rebound" (wheel extended lower than gravitational equilibrium) such as when going over driveway ramps at an angle. This is inevitable since increasing the caster is done by moving the tire rearwards in the wheel well. Also they will tend to make the tires "scrub" and "hop" more during very low-speed tight-turn situations like pulling into a parking place. This is also inevitable due to the geometry of the design, which toes the tires inward more as the wheel is turned (beneficial for road-speed handling). All of these things are a matter of COMPROMISE: you GIVE UP something that either doesn't matter (the "scrubbing") or that you can avoid by educating your driver (the fender well rub) in order to GET something you want (good handling, positive and reassuring steering "feel", acceptable tire wear). Which, with the old pizza-cutter stock wheels and no decent tires available for them, if you can ever find a decent set of tires, you'll definitely want them to wear only minimally. Back in the day, you could get state-of-the-art tires in all the new designs for those wheels, back when they in turn were "state of the art"; in 2022 however, given that the state of the art has moved on SO FAR from the 80s, that about the only tires you can get nowadays, are crap like Goodyear, BFG, off-brands like Cooper, or store brands like Pep Boys or whatever which since those guys don't "make" tires are usually just private-labelled some one of those other crappy things. Kind of a shame really. Butt, to be "competitive" in 2022, it's just about unavoidably essential to get modern-sized wheels, that you can actually buy modern tires for.
As I mentioned, front-end alignment in these cars is done by moving the top of the struts around. This is quite eeeeeezy to do yourself, in your driveway. I don't mean you can align it yourself; BUTT, once you get it "aligned", you can tweeeeek on it SLIGHTLY yourself, to optimize it, if you don't find it to be "perfect". To put the amount of movement into perspective, a change in the strut location of about ¼", corresponds to a change in caster or camber of about 1°. Not exactly of course, or really even all that close; but close enough to be a basis for making SMALL INCREMENTAL tweeeeeks.
Whatever you do, DO NOT let the "shop" set it to the "factory" specs. Those are TERRIBLE, and not applicable to ANY situation I can even imagine. They call for near zero caster and positive camber, the combination of which makes the car wander uncontrollably, have a very vague center feeling to the steering (maybe not even tend to re-center at all after a curve), and EAT tires like it's late for lunch.
Lowering the car degrades many aspects of these cars' suspension geometry, although if you have springs that "lower" the car by 1", odds are, it will sit actually HIGHER than it did with the 35-yr-old stock crappy things in it, after you do all this work. The front was designed such that the ball joint center was level with the control arm bolt center, when new; if you put stock ball joints back in it, that will now be disturbed, and there's not much you can do about it. The rear however, was VERY POOR when new, and gets EVEN WORSE when one of these cars is "lowered", or for that matter when the crappy OEM "WS6" springs lose their tension and sag, like all crappy stock springs do. These cars had RUTHLESS wheel hop the day they rolled out of the showroom, and "lowering" whether intentional or merely by way of wear-out just makes it worse. LCARBs are the cure. You may want to consider a set of those.
That chart that skinny posted agrees very closely with my opinions. Only significant difference is, it calls for more toe-in than I like. Might have to do with tires: the more "sticky" the tires are, the less toe-in that's required, to a point. You always need "some"; more than "not enough", but not "too much". Very precise, that. But, you could take that chart to your alignment service, and ask for something between the "street" and "hard street" settings, and have a good starting point.
Note also, you can change the toe, by loosening the tie rod sleeve clamp bolts, and turning the sleeves. The threads are somewhere around 16 tpi, which, given the length of the steering arms on the spindles, will give around 3/32" on each side (3/16" total) per full turn. A quarter-turn on each side is a tweeeek; a half-turn is ALOT of adjustment; a full turn is INTO THE OZONE LAYER. You can look at your tires after a drive and see if there are tiny scrub marks from outside edge inward, after a few miles of completely straight (curves allowed, but no turns) driving; and, feel the temperature of the tread or even (gasp!) MEASURE with your IR thermometer, comparing from one edge, to the middle, to the other edge, after such a drive. Ideally you want the temp to be relatively uniform all the way across. Certainly, not MUCH higher at one edge than elsewhere. And, if your steering wheel isn't PERFECTLY centered, you can tweeeeeeeek that with the tie rod adjusters as well; 1/8 turn on each should produce a noticeable change in centering.
But, you could take that chart to your alignment service, and ask for something between the "street" and "hard street" settings, and have a good starting point.
