What causes rear tire cupping? Nitto g2 555s

[ORRadtech]

The OP said he's running a staggered setup ant the tires are directional. They're not possible to rotate short of having them dismounted and remounted in the other side.
Unless you don't care that you're running directional tires backwards...

I know, I was responding to a different post who said you can't rotate directional tires.

I suppose I should learn to quote better.

I think you were probably talking about my first post on this. If you'll read it, I was talking about the OP's staggered set up.
You can absolutely rotate directional tires front to back on the same side with a square setup.
I was simply pointing out to another poster that the OP cannot do that with his situation.

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[ShadesOfBloo]

I don’t know how to change it and neither does my alignment guy I guess. He said every time he tries to adjust it it goes back to what it was which is -2 something. I’ve only ran into one shop here in AZ that will align lowered cars. So it’s a pain in the ass.

You might need to bite the bullet and buy adjustable arms or something.

If you contact a local sports car club that does autocross and stuff, I bet they could recommend shops for alignment. (A chapter of the SCCA would do, if I couldn't find anyone else.)

The more adjustable parts you have in your suspension, the less it sounds like a DIY job.
I know people that do alignments in their driveway with string... They probably started on something simple before they did it with their super-adjustable race car.

 

[CobaltFilly]

@NightmareMoon How do these look to you? 1.5k miles and an autox since I last rotated. Fronts look great. Maybe need to rotate again…
-1.9 rear camber, no rear toe (zeroed both sides).
Michi 4PS 19x11s square 295/35/ZR19.

 

[K4fxd]

Probably not the cause but I like a bit of toe in on the rear for stability under hard braking.

Hard to tell from the lighting, underinflated??

 

[CobaltFilly]

Probably not the cause but I like a bit of toe in on the rear for stability under hard braking.

Hard to tell from the lighting, underinflated??

36/37 when hot, sits around 32/33 when cold.
Perhaps underinflated a tad…

 

[NightmareMoon]

@NightmareMoon How do these look to you? 1.5k miles and an autox since I last rotated. Fronts look great. Maybe need to rotate again…
-1.9 rear camber, no rear toe (zeroed both sides).
Michi 4PS 19x11s square 295/35/ZR19.

how do they look as far as what? They look like MP4S. Do you have some concerns?

 

[CobaltFilly]

how do they look as far as what? They look like MP4S. Do you have some concerns?

Just look like some ruffled edges…cupping I assume is the word.

 

[K4fxd]

The lighting is not very good but all I see is what looks to be under-inflation wear on the outside edges.

Cupping is flat spots

 

[NightmareMoon]

Just look like some ruffled edges…cupping I assume is the word.

No thats not cupping, you can look up cupping online for pics.

you’ve got some normal tires with moderately hard use.

 

[CobaltFilly]

No thats not cupping, you can look up cupping online for pics.

you’ve got some normal tires with moderately hard use.

You rock as always brother. Thank you

 

[K4fxd]

 

[NightmareMoon]

The lighting is not very good but all I see is what looks to be under-inflation wear on the outside edges.

Cupping is flat spots

not even under inflation.

Thats about normal if you’re driving hard. Street tires like the MP4S will roll about that much under hard use when inflated properly. You do WANT wear down to about that spot on the treadblocks and then fine tune with a pyrometer, not by eyeballing it on the internet. If he had wear past the edge of those shoulder treadblocks (which he doesnt), I’d declare too little pressure or camber or too narrow of a wheel.

 

[K4fxd]

You have better eyes than me.

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