Hopefully this is the right section. I have a 03' miata, lowered, pinch weld seems to be a hair over 4" front and just under 4.5" rear. The alignment shop I took it to specializes in setting up racing and high end cars, the guy seems to be extremely knowledgeable while I myself am not. Current specs:
Camber: -1.8 F, -1.7 and -1.6 R
Toe: 0F .03R
Caster 5.5F

The alignment previous to this was all over the place. The shop I had it at for a quick alignment put me at -.8 camber in the front. For tracking this accelerated my outside tire wear significantly. The tracks I run are hard on the left side. I am hoping the -1.8 I am currently at now will help even out the wear, but my shoulders are just about toast. I will be looking for new tires, and want to ensure the longest life possible as these are being tossed with a ton of inside tread yet. Question time:

1. -1.8 camber seems wrong for how low my car is. I would imagine I should be able to obtain at least -3, but the shop said they could not get it lower and even across the car. I am looking for bent components?
2. Is my rear camber enough to keep even wear on the tires? If I need more, what possibilities do I have?
3. Bolt in extended lower ball joints for the front. If I have my alignment set at -1.8, can you just bolt these in and leave the alignment? I have never done ball joints, are they something you can swap in for a track day?

Thanks.

 

 

I am currently running Federal 595 RS-RR tires. They are listed as a 200tw, but are extremely grippy. Right now I have 205 section width tires on my 15x9 wheels, there is a slight stretch. Once these burn out I will replace them with 225 federals (apparently they just released this tire in 225 size).

 

On my NA at 4.5 inches high(from the pinchwelds), I can only get -2.4 camber in the front. In the rear I'm running -2.0. After doing about 7 track days on the car, I have noticeable outer tire wear compared to the middle and inside on all four tires. I need more camber! I'm running 205 maxxis vr-1 at the moment.

I don't want to go any lower in ride height to get more camber, so I'm going to install ELBJ in the near future. From what I read, if you just add in ELBJ, you'll gain massive toe-in because the steering rods need to be adjusted for the extended distance they now have to reach.

 

Before ELBJ's my NA had a hard time just hitting -2.5 with caster compromised right around 3 degrees and ~4" pinch. With ELBJ's I hit -3.2 easy with 4.8 caster and nothing below 4.5 pinch. If not class limited just get ELBJ's, it's the easy button, but requires re-alignment. If you drive the car to the shop you'll at the very least need to eyeball your toe.

 

FWIW me and you seem to have basically the same car (Mine is a 2002).

I shot for just under 949's current dual duty specs and ended up with pretty close to your numbers.

So far on two track days and about 1k street miles tire wear is fairly even. I'll check again tomorrow since it was raining after coming back from the track today. Certainly much more even than the -1.0F, -1.5R another alignment shop gave me because they thought my requested specs weren't correct. Previously I could only get about -1.2 on the front left. Swapping out the LCA let me hit my requested -2.2 on that side but then the right front was off. Since I had a track day that weekend I opted to run about -1.9 in front and -1.7 in rear. I'm sure the rears can hit pretty decent numbers, I haven't heard as much issue getting numbers from the rear as I have the fronts. Usually it is the FLCA that gets bent slightly jacking up your alignment numbers, at least according to Dr. Google. In my experience it seemed to be right. Something to do with the arm being slightly weaker or something?

I suspect I can hit the current Dual Duty alignment numbers if I replaced my right side FLCA. That being said I have some 949 ELBJ on standby anyway ready to go in whenever I man up and purchase a SADFAB bushing kit. What I can tell you is that the car drives great with these numbers and the same springs as you run. Tire wear seems pretty spot on (no inside shoulder wear that I can notice) and no outside shoulder wear either.

 

I ran in the neighborhood of -2 to -2.5 for a season (last year) and shredded the outside shoulder of a couple of sets of RC1s and VR1 streets. At -3.2 I'm seeing much better wear on RS4's for dual duty, but still not enough camber for hoosiers.

 

So it sounds like its pretty dang common to have horrible camber numbers. Some people can hit more some less. These ELBJ seem like the way to go. I guess I didn't realize this was such an issue even once we get our cars lowered. Thanks all.