Auto x tire pressure

[AppleSauce]

On stock tires what air pressure should i have for auto x?

[GSpeed]

Start at 28 or 29, and bleed off between runs to maintain 32 hot. See how you like that, and maybe adjust front/rear to change the balance of the car.

[strat61caster]

I concur, low pressures to allow the tire to grip and flex, many run higher pressures for fear of the tire coming off the rim on cars that are well over 3000 lbs.

Since its your first time you'll be lost in a sea of cones I wouldn't worry too much about adjusting, set it anywhere from 28-35 and forget about it until its time to head home.

[mabviper]

It depends on what your goals are.

Do you want your stock tires to last w/o the sides chunking? If so, I'd set it to 40 psi to start and mark it the sidewall with chalk to see how much it rolls. If you don't care too much about tire wear, I'd leave it at factory pressures, 35 psi and concentrate on driving.

FWIW, I run 42 psi fronts and 40 psi on the rear when I autox. I'm still on OEM tires after 2 years of autox and a few track days. Though, autox is really hard on OEM tires.

[Locust]

I believe I was running 31 front / 29 rear when I still used the OEM tires. That's at the start of my runs mind you. They'll always be slightly higher during your runs so adjust accordingly based upon how early/late you need the grip for the course.

This type of thing is where data comes in really, really handy.

[ButteR]

Not to try and advertise a for sale here, but this is good knowledge for someone new to autoX...

Save your oem Michelin tires. They're great daily drivers and cost $209 brand new per tire. Go out once with your stock set up and see if you like it and if you do get a "dedicated autoX wheels/tire" set up...

Since you're new to AutoX best money spent is seat time but it's still good to have a dedicated set up if you daily drive the car.

I'm selling my oem wheels so you could have two sets of oem wheels, one with tires for AutoX and one for daily driving. Then a year from now, if you're hooked, look into spending some money on more expensive pieces...for now, keep it cheap.

[AppleSauce]

i heard u can get nitrogen N2 in ur tires for like 20 bucks and dont have to adjust for temp changes. im fairly certain im addicted and havent missed an event since my first time out. anyone tried nitrogen in tires before?

i do plan to get stickier tires come next season. not sure about doing rims and having dedicated set quite yet. will have to see how budget looks when the time comes.

id also like to thank you guys for your input. much appreciated.

[Locust]

Originally Posted by AppleSauce

i heard u can get nitrogen N2 in ur tires for like 20 bucks and dont have to adjust for temp changes. im fairly certain im addicted and havent missed an event since my first time out. anyone tried nitrogen in tires before?

I suggest you don't do that. Your ideal autocross pressures will be lower than your DD pressures unless you don't want to have even tire wear. When you need to refill after an event to turn the warning light off (assuming you actually run something in the area of 27-33 PSI like most people have seemed to settle on) you'll have to carry compressed nitrogen around with you or drive to your tire shop and have them do it.

http://www.edmunds.com/car-care/shou...-nitrogen.html

For your reading pleasure just in case you were wondering how it actually works, though.

[SeanRTR]

I've never done any kind of event on the OEM tire, but those pressures seem way too low to me for autocross, on all season tires.. How is the front OEM tire not rolling over at 27-32 PSI? I'd be running much higher.

[mabviper]

I agree. 1 autocross at 27 psi and your shoulders/corners are going to have significant damage.

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[strat61caster]

I ran mine at 35 psi cold with no shoulder damage, minimal scrub on the outside, figured they'd be good lower if grip was desired, probably right though preserve the DD tires so you can drive home safely. They felt like crap at higher pressures, got better as I let air out.

[Locust]

Originally Posted by SeanRTR

I've never done any kind of event on the OEM tire, but those pressures seem way too low to me for autocross, on all season tires.. How is the front OEM tire not rolling over at 27-32 PSI? I'd be running much higher.

Originally Posted by mabviper

I agree. 1 autocross at 27 psi and your shoulders/corners are going to have significant damage.

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I can only go off of where the wear lines end up on the tire and at 31/29 for OEM it was right where I wanted it.

I run my RE71s at 29/27 and get even temperatures across the board with wear right at the triangle.

Every car is different and every driver is different. You've gotta go with what works for you.

[TrqlessWonder]

Originally Posted by SeanRTR

I've never done any kind of event on the OEM tire, but those pressures seem way too low to me for autocross, on all season tires.. How is the front OEM tire not rolling over at 27-32 PSI? I'd be running much higher.

I did an event or two on the OEMs with all four in that range - was 30f/28r iirc at a tiny lot last season. How? LRR tires is my take. All-seasons with stiff-ish sidewalls just not gripping hard enough to roll them over very far before they start sliding. Those are just the pressures I settled at when I finally had some indication that I was using most of the tire.

[R2]

I ended up running 40F/38R hot on the Primacy's, there was still roll over but I felt it was acceptable. As pressures went down I found predictability and response dropped, lap times dropped too.