Help diagnosing weird left turns.
 

First the background on the car. It's a 2017 series.yellow with flex Zs and spc rear lcas+toe arms. I'm pretty sure it was a stance car since when I got it it was lowered all the way down and riding the bump stops with uneven damper settings, ride heights, and preload at all 4 corners. Even after I raised it back to stock height it had about -3.5° camber in the back. I'm not sure what the front was but it was maxed out on the camber plates until I set it back to the 0 line on them. I destroyed the front right tire in about 3 weeks of owning it because the alignment was so bad. The front right also had 0 preload and was 1/2" lower than the left when I got it. After getting new tires and an alignment I double checked things a week later and all seemed well. A week after that the left rear slipped so far out that I was crab walking down the road and had to get my alignment redone. I also had a sway bar bushing in the front right that was obviously bad so I replaced my sway bar bushings with poly. (I tried getting OEM but they just never shipped and I had a deadline to autoX it.)

Ok now for the whole reason I'm posting this. The entire time I've had the car I've had an intermittent issue with weird wide left turns at between 50 and 65 where the car feels like it's loose then tightens up then gives again. Sometimes it will even trigger VSC. The easiest way to make it happen is a freeway interchange where you have to take a big sweeping left but it's not 100% that it will happen. I thought I fixed it with the alignment(s) and sway bar bushings but no. With the car in the air I don't notice any movement when I try to wiggle the wheels vertically like it would be a ball joint. I did get some play on the X axis when trying to check the tie rod but after I replaced the sway bar bushings I tried to check from underneath and I wasn't feeling any play anymore. I'm stumped at this point. I'm leaning towards either the pillow ball or the tie rod on the RF but I'm not sure how to be sure at this point. Any help or suggestions would be greatly appreciated.

How many miles on the car? I may be wrong (which I often am), but new sway bar bushings shouldn’t fix any x-axis play in the front wheels. That would be your wheel bearings. I think they are $120/side, and I would start there. Mine had hilarious play at 110k miles.

Just over 70k. I meant x axis as in across the face of the wheel at 9 and 3 oclock. Wouldn't wheel bearings have play regardless of if your hands are top and bottom or on the sides when you check? I meant I thought the bushings fixed the turning issue not the play but it was sloppy enough I wouldn't be surprised. You could see the end links move when I tried to shake the wheel.

None of my cars (FR-S is the 5th) had any play in the wheel when the bearings were fine.

If there is any detectable movement in the wheel bearing or a humming noise when you load up one side of the car then the bearing is dead.

They seem to be somewhat delicate in this car when tracked.

There's no humming or indication that the play is in the wheel bearing. I got the car up and got the wiggle to come back only at 9-3. There was definitely a bad inner tie rod which I got on video here https://youtu.be/pW0DcuW0Gsg

I replaced the inner and outer tie rod on the passenger side. It has improved the steering and eliminated the lateral play when i try to shake the wheel but my high speed lefts will still almost jerk inwards then loosen up and sometimes kick off the VSC. Low speed turns seem fine and if I get to about 75 it doesn't seem to do it. From what I could see the steering rack is very solid. I did notice the preload was gone on the coilover again and tightened that back up. I've also found this one adjusted way off but I'm not 100% sure if it's loosening itself or if the alignment guys messed with it. I can say I'm not going back to them and I'm trying to get in at a reputable performance shop for another alignment. If you watch the video does it look like the coilover is too loose? I'm thinking the top mount could still be an issue or the whole assembly may be bad. I don't see any fluids leaking anywhere on it though.

Any more help or suggestions would be appreciated

Edit: got the front end up and some of the movement at 9-3 is back. 12-6 is rock solid and I can't see any movement from the ball joint or wheel bearing from underneath. It looks to me like all of the movement is coming from the pillow ball here https://youtu.be/0cUHLWSnlR4 looks like I'm gonna have to get some new coilovers no? Now just to decide between SS1 and T2 RCEs

Update: added some camber and I noticed that the speed that it happens increased. Also, tightening up the damping makes it less of a harsh change and switching to track mode eliminates the tight then loose feeling. Now you can just feel it load up and stay tight. Idk if the vsc was messing with something without tripping the light or what but track mode definitely feels more stable.

Yeah that’s some messed up movement at the pillow ball, but you could just rebuild the camber plates if you wanted.

I could but these flex z aren't really what I'm looking for. I need something more trackable anyways.

Oh for some reason I thought you had CSG Flex A...yeah dude perfect time to upgrade lol.