Alignment Advice Needed

[Zero3210]

Hey everyone, been brainstorming this for over the past 2 years but still can't seem to figure certain things out so hoping for some guidance/clarification. My 86 is on 18 x 7.5 +45 and 225/40s atm but still essentially bone stock in terms of suspension components.

Recently due to inappropriate lug nuts, 3 of my studs stripped and needed replacement. I attached 2 different alignment reports: one from before the stud replacement, and the other directly after the stud replacement. Only the rear left wheel studs are affected, which is probably why the camber was off. From what I understood:

(1) Caster on our cars cannot be readily adjusted.
(2) Camber on our cars are also non-adjustable unless we install camber bolts / control arms, etc.

So can someone explain how within the short space of time the caster values have changed quite dramatically, and also how did the technician adjust the camber if it is supposed to be non-adjustable? I am aware that placement of the sensors are paramount for accuracy but even so, aren't the values too much off for merely a mild misplacement?

Apologies if this is posted in the wrong section or if it's a question that's been asked already but my limited search skills did not show otherwise x.x

[churchx]

Indeed, as stock, our cars have only toe adjustment. Adjusting toe affects also camber though. I'm not that suspension savvy, but maybe caster too?
Also there is some slack/play in many connections, so unbolting/retightening some suspension bolts at extremes of that minimal slack may change something too. Adding adjustable bits, like camberbolts, camberplates, eccentric bushings, adjustable control arms, greatly up adjustment ranges allowing dialing wished settings way outside OE alignment and simplifies precise dialing instead of fscking around within that tiny slack of bolt connections.
Also it may differ if one sits inside or not, while alignment is dialed. Maybe also there was some spring sag? And of course there might be differences, if in one of alignments, alignment techs skipped mandatory check for even tire pressures prior aligning, and it was off in some tires. And if it's done in same suspension shop, but long time passed between alignments, maybe alignment rig lacked calibration in one of cases? Also there might have been some heavy hit to suspension bending something, between alignments
I'm not sure if all of what i spouted out is all true, it's what seemed possible. When i had first alignment for this car done, i already bought some adjustment bits (back then - camberbolts), so that's not exactly experience of what's possible to have happened between alignments on everything completely stock.

[Zero3210]

Hey thanks @churchx for the lengthy response. Apart from the multitude of variables that you have so kindly shared, are you implying that caster and camber unintentionally gets altered as toe is being adjusted?

[churchx]

I know, that camber is linked to toe and adjusting one will change other. Not sure on caster. Hence the warning at end that all my babbling might be not so credible .
Then again, caster imho doesn't affect handling that much. Just a bit stronger (heavier steering) or weaker tendency returning wheel to center and a bit changed dynamic camber gain on turned wheel. I usually don't care what it ends up at and if it's even and so on. Camber +/-0.5dg also not THAT big of issue, at least in daily driven only car. I'd concentrate on getting toe right, precise, even (i prefer OE like toe: zero toe front, slight toe-in rear (+0.1dg each wheel, +0.2 total rear toe)), as even small toe values in degree fractions (or inches or mm, depending what units alignment rig is set to for toe) or their unevenness may add noticeable handling changes and/or handling issues/artifacts.
P.S. I'd advise to get at very least camberbolt set for front, even if you want use just OE alignment. They are cheap, and should allow for alignment tech to dial at least front toe & camber easier/quicker/more precise. Sidegain - they allow dialing more negative camber, thus allow dial out some of that understeer bias from OE alignment. Adjustable rear LCAs cost noticeably more, hence not suggesting them.

[Zero3210]

@churchx yeppers. Already having plans to swap the top bolt w/ a 14mm oem crash bolt (which after much research is essentially the same bolt as the bottom bolt) for some camber adjustment but just wanted to understand stock alignment settings and dynamics before I go down that route.

Basic alignment adjustments costs about $25 in these parts but when camber adjustment is needed, price could easily shoot up 4-5 times. Once upon a time, I was strongly recommended to get my camber adjusted by the 'technician' as it was "way off" and "bad for my tyres/handling". Noob me agreed with the suggestion but I didn't quite understood how they were going to adjust camber if our cars' cambers are non-adjustable. Paid $160 for the service and never went back. GG

[churchx]

Well, i'd prefer eccentric lobed camber bolts to oem crash bolt. Imho they make dialing a bit easier by turning, vs crashbolts (=normal bolts of smaller size then specific mount hole), which you untighten, skew wheel manually and then tighten. For reference, for lower 14mm hole one can use SPC 81305 camberbolts, but if for upper 16mm hole, Whiteline KCA416.
Stock alignment values. It's ok for daily except imho too understeer biased, for which imho mostly front zero camber is responsible. It also has too wide "green"/allowed ranges of settings imho. In general for DD only car i'd probably would go for similar, except maybe -1 to -1.5 front camber, and obviously more precise & even then those allowed ranges (especially toe). For tracked car one needs much more negative camber (-3 to -4 front, -2.5 to -3 rear) for more even tire wear and better grip, or otherwise you'll have reduced grip in turns and uneven wear/badly worn outside of tires. But if one doesn't track, no need for that much camber.

[thomasmryan]

up front, more caster will increase the rate of change (derivative) of the camber. you might research some of the aftermarket offset control arm bushing to get it closer to stock specs. this is the simplest solution running something outside the factory rim specs.



the rear being non-adjustable kinda sucks. i would prefer less rear camber as i want the inside tire flatter on the road exiting a corner and under heavy downhill braking. i like a slight amount of slip but not enough to trigger the 'puter.



taking out front camber pulls the toe in. adding front camber, splays the front out.



zero toe can be 'busy' as speed increases but decreases tire wear.

[Ernest72]

After talking to some shops that race, the preferred way to get net camber upfront is with camber plates. When your suspension goes you should likely replace the top hats anyway.

[Zero3210]

Appreciating all the feedback but I think one question has still yet be answered x.x

I.e. how is camber adjusted on stock suspension if it is supposed to be non-adjustable? If you see my before after values (see pic above) my 'rear left' camber has been adjusted from -2.00 to -1.56 o.O

[churchx]

camberplates for camber increase are often chosen as easing camber "on-site" changes on track. But they can increase NVH, and depending on design, increase a bit stack height, and cost 5-10x more what camberbolt set costs. For DD only car see no need of camberplates. You don't need higher adjustment range, don't need on-site changes, but will pay more and NVH increase. Also i might be wrong, but IIRC because of SAI some advise adding camber at knuckle, then at upper mount.

[strat61caster]

Originally Posted by Zero3210

Appreciating all the feedback but I think one question has still yet be answered x.x

I.e. how is camber adjusted on stock suspension if it is supposed to be non-adjustable? If you see my before after values (see pic above) my 'rear left' camber has been adjusted from -2.00 to -1.56 o.O

Multi link suspension design means that adjusting toe affects camber when you only have one adjustable arm.

[NoHaveMSG]

Originally Posted by Ernest72

After talking to some shops that race, the preferred way to get net camber upfront is with camber plates. When your suspension goes you should likely replace the top hats anyway.

I have heard the opposite from a couple sources on our platform.

https://www.ft86club.com/forums/show...1&postcount=36

[churchx]

Yeah, on this forum i saw few times advise to add camber at lower mount, not top.

Imho main reason why camber is added at topmounts (camberplates) by some race shops, is relative ease for onsite camber adjustments on track, and that's it. Race/motorsport .. for rally for example, camber is changed by changing lower mount slotted hole fixed offset inserts. Thus for "normal people", that don't do frequent onsite camber adjustments, i'd use topmounts at most to get some extra camber if needed over range ontop that of camberbolts and that's it. It also is much simplier for tech from below of car to adjust at lower mount, with two wrenches for toe & camber adjustment nearby while looking at alignment rig screen, instead of crawling from below up and back few times, to adjust toe or camber separately.

[Ernest72]

Originally Posted by NoHaveMSG

I have heard the opposite from a couple sources on our platform.

https://www.ft86club.com/forums/show...1&postcount=36

But his suggestions for changing at the hub are not just a simple camber bolt, he’s talking about setups that’s are slotted to prevent movement. I get it that camber bolts are the easiest to do for a DD, but plenty of camber bolts are moving on pot holed roads. Plenty have had no issues either so YMMV. He does mention that many fast cars use plates.

I think you need to decide what you are trying to achieve with the car. Honestly, I have neg 0.3 and 0.8 on my stock suspension and the car drives great for spirited runs and DD. When my suspension goes I will decide which way to go. My car is a DD and I drive enough miles that I don’t want to much camber wear. I think for DD, people go to far with the camber sometimes.