Miata wandering and turn in.

So the ‘97 has been altered by a hooligan prior to me. I have two “issues” currently and need some advice. 

It wanders at highway speeds, but only on our massively cupped highways. On fresh asphalt it’s fine. It was so bad last night that it took maximum muscle control to maintain a straight line and not get pulled over. Wife actually asked “how many beers did you have?” (Answer- 2)

Second issue- turn in is nice and crisp, but not linear. I get the initial turn in, then it feels like the sidewalls get ED, after that “feeling”, the rest of the turn in is back to linear. Almost like the suspension has to settle, but not soon enough, I really feel like it’s the tires. 

 It came “slammed” on cxracing coilovers. I brought the height up a bit to a respectable level. I’ve been reading about camber thrust and that, possibly, roll center adjusters, increased caster, or camber plates might help. 

It doesnt help that it rides on cheap mastercraft 440 195/65/14’s (aka balloons). I’ve increased psi all around to 40psi in hopes of preventing the sidewall flex. 

What say ye, crowd? 

Have you actually had it aligned at a real shop?  I'd start with that and see.  The tech might spot a broken or worn part under there. 

 Overinflating the tires probably isn't helping, back them down to 30 and call it a day.

Yeah sounds like ridiculously wrong toe (probably too much toe-out, specifically) and/or massively unequal caster.

What he said ^^^ (EDIT, I was late and was referring to KyAllroad, not that I disagree with GameboyRMH...)

Start by establishing normalcy. Make sure you've got no broken or badly worn parts, and a sane alignment.

In reply to KyAllroad (Jeremy) :

Wouldn’t the squishy effect be emphasized? I’m trying to get an alignment done (by a real shop, not some hack tire place). 

That is all alignment and tires.  No matter how good the alignment guy is, the tires will still be crap.  Suspension bushings are probably shot too.  If it is going to be really low, you will want adjustable sway bar end links too

In reply to Toebra :

Cool, thanks!

Re the turn in, it might also settle on the bump stops (usually the rears first, as that end has hardly any travel) and that might be the part that feels "weird".

Track alignments tend to have little or no toe-in at the front, which can make the front feel like a bloodhound who's eaten a bag of weed.

Is it massively lowered?  Check bumpsteer. 

NA Miata is not going to like being slammed in the weeds, unless all you plan to do is stand next to it and look cool.  There is a wealth of information  here regarding Miata suspensions.  You want to set the ride height before aligning, as changing height will impact alignment.

When you raised it back up, I’m sure it changed the toe.  Also check the spindles.  Spec Miata guys like to heat the spindles for a little extra camber.  Make sure the previous owner didn’t do that as well.

Update: got a sweet alignment done by a buddy with a good machine (after hours dealership). He got me as close to the FM suggested settings. 

HOLY COW what a difference. This thing drives awesome. And the tramlining is reduced so much! Thanks everyone! 

As you have discovered, there is a reason when people talk about an ill handling Miata the first response is always:

Get a proper alignment.