Fix for uneven camber?
 

I am running ~4.25" pinch weld height on my 90 Miata (stock suspension aside from coilovers) and max out at -1.8 degrees of camber on the front passenger side, while the front driver's side hit my target of -2.5 easily, at the middle of the adjustment range for the camber bolts. Based on some crude measurements it doesn't seem like my control arms are bent, and I'm starting to wonder what the right course of action is. Are there any simple tests to figure out what's tweaked? Should I bring it somewhere to get it inspected? I'm honestly tempted to just throw on an ELBJ on the passenger side and call it a day. Would this be a bad idea?

I would replace the passenger side control arms and try again.

If that doesn't fix the issue what would be the best next course of action?

Exocet

Lol sounds legit

Curly has the first step right.

How long have you had the car? You wouldn't be the first to have a bent front subframe (aka K mount).

If the PO hit something hard, bent the arm and replaced it but either didn't look further, or did and said stuff it, I'll make it someone else's problem ...

Replacing a subframe is not trivial, but not the most difficult job either. If you are confident in your checking the arms for accuracy, it is either the subframe, or a bent upright/spindle.

I've had it since 2013. I don't recall having this problem when I first got it and I've swapped so many things on it with months (or even years) in between driving it, so I haven't done a very good job with keeping track of when and how problems arise. Hopefully the subframe is not bent because I really don't want to pull out the engine again...

I think I'm gonna start by swapping the upper control arms because the lower one is almost certainly fine.

Why do you think that?

I bought and installed another (used) LCA. I suppose it's possible the replacement is bent as well but it would have to be bent the exact same amount because the camber (at least seems) unchanged.

Someone will correct me if I'm wrong, but typically it's hard to get more than -2.0* camber on stock control arms/lower ball joints. This makes me think that it's the driver's side that's messed up, and the passenger side is in fact to spec - which is why even with different passenger arms you're still getting the same result.

-1.8* is about what I expect in stock form, the fact that you hit -2.5* in the middle of the camber bolt range is ringing alarm bells for me. On my NB with coilovers I could only hit -1.8*, until I put in extended lower ball joints.

Do you have a spare driver's side arm to swap in to check and compare?

Interesting hypothesis. I don't know what camber range to expect at my ride height, so you may be right. I don't have a spare LCA for that side, unfortunately. Not opposed to buying one, but not unless there's a reasonable chance that it's the culprit.

Yeah, I guess I'm used to seeing ELBJ numbers. I'd concur, although 4.25" is fairly low so I still think 1.8 is a little low for max camber at that height. Sounds like you could do 3+ on the other side, which is the bigger alarm bell on stock ball joints.

Data point - my NA8 hit 2.5 rather easily at SPM Dual Duty ride height. New OEM lower joints, Moog upper, and stock "D shaped" alignment bolts.

I think NBs have a different suspension geometry so maybe that's why they are more limited.