Base conditions: 2013 G37 Sedan 6MT. Just put Coupe 19" staggered on it with 245 fronts and 275 rears. Took to be aligned and it is *twitchy*. I mean full lane change when you hit a painted line twitchy.

Attached HTML-ized excel list.

I basically think this guy has no idea what he is doing. Any suggestions?

 

This was after giving him the factory service manual pages on alignment, by the way.

 

Mike, I think you need to suck it up, cut your losses and go to another shop.

You're not wrong to be frustrated and upset, but it's not worth it.

 

Oh, I'm done with this guy for sure. I found a loose lug nut (tight, but not to torque) and that tells me he didn't check any of the preconditions first.

I'm hoping the loose lug nut is just because I hadn't rechecked the torque after driving it a bit, rather than an issue. I'm wondering, because the wheels aren't the same depth in from the fender from left to right.

My other theory is that the shank nuts are slightly too long for the thickness of the wheel and are bottoming out before developing the proper amount of clamping force. The prior wheels had acorn nuts and only had about 3 threads in, so they were musclefarked on there - 200+ ft lbs at least.

 

Also - what I was looking for was any suggestions for the settings I should be seeing. The FSM says small amount of toe-in but not a degree value that he could register on his machine (his only did .1 degree increments). If I'm reading FSU-23 right, I should be seeing .08 - .25 degrees toe in. RSU 25 looks like .24 - .47 degrees toe in.

My reading that value list looks like I have toe-out everywhere.

 

I've never had luck with aftermarket nuts on these cars.
The taper of the oem nut helps center the wheel which if its off will cause vibration.
If the nut is too small it wont tighten the wheel all the way.
You need a different alignment which sucks because alignments are not cheap.

For example: My buddies and I aligned the car at Nissan and the rear specd out however I'm noticing feathering on the pass rear wheel.
If you dont have friends with alignment racks I suggest buying lifetime alignment that some shops offer.

 

The OEM nuts on the 18" duckfeet are shank & washer nuts - just rusty chrome. These are new and black oxide, but otherwise should be the same. Manufacturing tolerances aside which may be the issue.

So far I've had Pep Boys try to drop my car off the lift and NTB tell me toe-out is normal. I emailed a local performance shop but they only do European marques. There's a tuner shop near me, I can drop by and see who they use.

 

I can't open your attachment.

 

let me see...

It amazes me how complicated HTML has become. A simple data chart becomes 5 files, a directory, and two different style sheets. Attached is a (hopefully) simplified HTML.

 

Alignment does not look to be your problem. Unless maybe an adjuster wasn't tightened. I had a little wiggle in the rear when a camber arm lock nut came loose.

 

Might want to check the bushings on any of the suspension parts. Had an aftermarket camber arm bushing fail causing the camber arm to wobble underload.

 

Check subframe and rear mount bushings

 

So the lug nuts were about 1/10" too long and were bottoming out on the bottom of the bolt hole. That is a very thin portion of the wheel so under driving stress it let the wheels flex. Basically the washers were butting up to the wheel shoulder but not clamping 100%.

Car is more stable now with proper length shanks but still normal toe-out twitchy. Sweet-talked the local euro racecar place into taking a look at my plebian japanese ride to do a better alignment.

 

My local road-race track has a suspension shop and they didn't bat an eye when I brought my G in for corner-weighting (I installed coil-overs) and height adjustment with the requisite alignment to MY specs. Not the cheapest place to get this done but the guys are indeed competent.

 

Where I live, even the hacks charge top dollar, so I have no problem paying for someone to do a proper job. Buy once, cry once.