Autox tire pressures. What do you run?

[Strugglebucket]

Just curious to see what other people are running on their 3g.

The sweet spot on concrete for me has been 48psi in front and 39psi in rear. I've only run on concrete this year, so those numbers might end up a little lower on asphalt.

I currently have 215/45/16 Kumho Ecsta XS tires on 7" wide wheels. -2.5 camber, +4 caster in front and -2.0 camber in the rear. Zero toe .

[Bglad420]

I've been running on asphalt/concrete this year. in my 89 Lxi Cope
Tires: 205/50-15 Falken Azenis RT615-K on 6.5"
Front: 36 Rear: 34, I need to bump up the front a little though.
-1.6 front camber, 1.1 Rear Camber, A little toe out.
ST front sway, Addco Rear, ST 1.8" Drop spirngs w/blues.

[Vanilla Sky]

Are you guys using tire pyrometers to find the sweet spot or are you just going by aw times or feel?

[Strugglebucket]

I don't have a pyrometer but someday I'd like to get one with a needle probe. I've been checking the shoulders for wear to see how far it's rolling over. It's easy for me to see with new tires. With my old tires I used chalk marks on the sidewalls.

I was kind of surprised at how much air I needed to keep the fronts from rolling over, especially with -2.5 static camber.

[2ndGenGuy]

48psi in the front? Wow, I assume that's after it's warmed up?

[Vanilla Sky]

That's what I'd assume as well.

[Strugglebucket]

yup.

[Bglad420]

Are you guys using tire pyrometers to find the sweet spot or are you just going by aw times or feel?

I chalk my tires, and use that as a starting point, then adjust as to how much the car wants to dive, or tail.

[Vanilla Sky]

http://www.soloracer.com/pyrometer.html

They're really not all that expensive, and will probably save tires in the long run.

[russiankid]

On 185/70/13's, I run 45-50psi all around. I keep it that way after every run as the tires do get hot.

[86AccordLxi]

You don't need a pyrometer, just need to watch the sidewalls to make sure you're not rolling over since that kills tires.

My car (obv. different) -- I run 37psi in front, and maybe 35 in back (star specs 235/40/17 front, 255/40/17 rear). Car makes a decent amount of power and still hooks up very nicely.

Star specs also have little arrows on the sidewalls and you're not supposed to roll past them. Less pressure (like 34-35) makes the front end bite better, but is harder on the tires.

[turabaka]

225/45-r15 Kumho V700's on a 15x8 inch rim with +35 offset.

I'm usually running around 35psi/front, and 30psi/rear. Sometimes a little lower than that if I need some extra bite from the tires.

[86AccordLxi]

Why v700s and not v710s?

[turabaka]

Why v700s and not v710s?

because they were 70 bucks a tire, and I really didn't wanted to spend 200 a tire on my first set of r-comps and accidentally flat spot them.

[86AccordLxi]

Fair enough.

Do you actually get heat in the them?

[turabaka]

Fair enough.

Do you actually get heat in the them?

I don't really have anything to measure internal temps with, so I can't really say as far as that, but the tires do appear to warm up. A couple autocrosses ago I actually had problems with them getting too hot. I was literally melting the rubber off the tires.

They apparently work decently as an autocross tires since the next fastest guy in my class is using v710's, and I've been beating him pretty consistently.

I'll probably move to v710's or Hoosier A6's next season though. Like I said these were to get my feet wet using r-comps.

[86AccordLxi]

What is the next fastest guy driving?

edit: N/m found it: 89 civic.

Fair enough.

[turabaka]

What is the next fastest guy driving?

edit: N/m found it: 89 civic.

Fair enough.

Actually on Sunday he was driving an 06 civic si with a decently heavy mod list (it's the one that beat me for fastest fwd on Saturday). He ended up cording his slicks, so someone let him co-drive their car.