I will be participating in my first AX event next weekend. I have street tires, all season (will change them in time). I am wondering what tire pressures you guys run with?

Any good points of advice?

 

I personally ran with normal PSI. I mean, ultimately, you want to be running it so you're used to driving in those kind of conditions when you truly need those learned skills in a bad situation.

 

All-season tires will be fine. Add 5 PSI. You can "paint" the side walls as above. That way you will be able to see if you are rolling the tires.

 

I added like 5 pounds and started from there and adjusted based on the course/if the tires were rolling over aswell

 

no one seems to go like i do, but im usually around the 25-27 mark when hot. It seems low, but it works great for me. I run 245/40/18 and 255/35/18 star specs. They may be a little more low profile then most others but i got grip like i have never had and i notice a hell of a difference with 27 psi vs 35.

 

When I dabble in STR with my car...I run about 34/32 hot in my star specs. I'm used to big hoosiers...so I haven't had much time to really dial them in really. With all-seasons, I would probably start higher....just my .02.

 

I generally run 44F/40R when I'm on my all-season Kumho ASXs (245/40R18 & 275/40R18).

For my big Hoosiers (295/30R18s), I generally run 50F/45R.

I've made lower pressures work, and they generally work OK, but I get a great big "groove of doom" 1/3 of the way from the outside edge of the tire tread.

 

As mentioned above, putting chalk or white shoe polish on the shoulder of the tire is a good way to judge whether your tires are rolling over too much. Look for the polish/paint to be worn off to the tip of the little arrows on your tire (there will probably be little arrows molded into the rubber if you look closely).

If the polish is worn to low, raise your pressures to decrease rollover.
If the polish is not worn enough, lower your pressures to increase rollover.

Don't forget to reapply the polish if you raise pressures.

Also, I start high and go down after the first run because it is easier to release air than add air.

With that said, don't be too much of a weenie by worrying that much about tire pressures. It's your first time and you're probably going out there to have fun. HAVE FUN.

 

Thank you for all of the great advice!!

 

If you really want some information overload, go to youtube and search for "Autocrossing with Dick Turner"

It may look a little hokey (vid from late 80s), but lots of good advice about autocrossing.

 

50/45 on A6s? What lower pressures "worked"? And how well did they compare to the much higher pressures? Most guys 'round here run their A6s in the 20s. . . HOT.

 

^ would like to know as well, I'll have my first autox on A6's this weekend. Hoosier recommends cars over 3000lb to 34-39 hot or 23-29 cold.

 

I've settled around 32 front 29-30 rear hot with my A6's.

 

Interesting. What have you found when pressures are lower? I have a feeling it's more stick at an expense of tire life, but I'm not sure. I know I got faster with lower pressures.

 

Once I get down to 25-26 in the front it feels sluggish to me.....

My temps are within 10 across the tire and the feel is better at the pressures I listed above.

On the opposite side...once I get above 34 it gets a bit warm in the center of the tire.

 

My latest numbers suggest I like 25HOT rear and 29HOT front. I do have a touch more camber, and my car may is 3150# with me in it, if those matter much. Still seems like a big difference; I'll try 29/32 hot this weekend.

 

My car is a bit heavier (3036lb w/o me and I'm fat). Hoping to get weight off the driver and the car down to 2940-2950lb for next year.

 

This is for autocross on 295/30R18s, and I generally set pressures on the tires cold since it's rare to have a run long enough to develop any significant heat in the entire tire carcass. I've also found that I like the tires slightly cooler (less than 130 degrees) than most people.

I was able to get the tires to work down to 32/28 PSI, but the tires started to develop a "groove of doom" and were more forgiving but also more sloppy. Times were roughly equivalent, but with the higher pressures I got a lot sharper steering and throttle/brake response -- but I also run my car a LOT firmer than most people do.

 

I also prefer the tires a bit cooler than most....I try to get them down to 120-125.