How are you defining your target tire pressures with 17/18s?

[GoodysGotaCuda]

I've always just ran a blanket 28psi front 30psi rear for my car and never really came up with a rhyme or reason.

What have you used to determine what psi you run on the street? Chalk the tread? Something else?

[CSG]

I use tire temps for pressure and alignment.

[Tsaints1115]

Mid 30 psi is almost a standard for most cars so it would probably be a safe starting point.

[GoodysGotaCuda]

I use tire temps for pressure and alignment.


And how does your testing process look? Skidpad? With varying temperatures at a controlled speed and radius?

[CSG]

And how does your testing process look? Skidpad? With varying temperatures at a controlled speed and radius?

Depends on what I am trying to accomplish. On the track its tricky because I typically see at least a 10 psi change usually more by the end of a race. For the street I would start in the mid 30's and drive in my typical fashion (whatever that is for you) and then take temps across the tires. If you can i would then do the same thing after a few laps on a road course. Then play with the pressures to get the temps across the tires as consistent as possible. For whatever reason i almost always end up putting more negative static camber in the right front when tuning by temps. For autocross I mark the sidewall on the fronts and add air until they don't roll over. I then typically match it in the rear or sometimes put a bit more to help the car to rotate.