AutoX Tire Pressure Settings

Nd4SpdSe · Post by **Nd4SpdSe** » August 3rd, 2006, 12:12 pm

Well, I went to my first SoloII event last weekend and had a blast
(pics: http://mx-3.com/phpbb2/viewtopic.php?t= ... 148b231260)

While I was there, people were constantly adjusting their tire pressure. I tried a few things, but either they were working or not, I don't know, I was running on adrenaline the whole time

But I was wondering, for tire pressure, that settings do you guys use. Although my car's suspension setup is different, it would be nice to have an idea to start off with.

Mazdaracer · Post by **Mazdaracer** » August 3rd, 2006, 1:04 pm

ya, tire pressures are setup dependent, tire size, tire brand, ambient temp, driver prefference, etc...

having said that, most FWD cars like ours can start with 36psi F and 38psi R and work from there.

Use a chalk line or shoe polish and mark the shoulders of the tires. This will indicate how much (if at all) the tire is rolling over. Ideally, you want the scrub line to be even with the indicators on the tire.

An inexpensive IR temp reader (Sears, Radio Shack) can be used to measure the temps accross the tire to help get the right pressures. Ideally, here you want the temps to be as equal as possible accross the tire. Measure inside, outside and center.

Welcome to the addiction!!!

Nd4SpdSe · Post by **Nd4SpdSe** » August 3rd, 2006, 1:59 pm

I got mixed opinions on rear tire pressure. Some said to stiffen the rears, some said to soften the rears to induce oversteer, not that I'm trying to drift, I'd perfect the rear rotate around the cones more easilly.

Mazdaracer · Post by **Mazdaracer** » August 3rd, 2006, 2:27 pm

you'll get a different answer for every person you ask....lol

i see by your sig, you have some Koni's, you can play with those to help rotation, as well as tire pressure.

I'd suggest getting used to the car and learning to drive an autox course. Seat time is your best friend. I wouldn't do any mods until you have a good few months with the car just how it is now.

A rear sway upgrade will certainly help the rear rotate, but i still suggest you don't touch it, just use what you have.

After that time, you'll have discovered what you may need (if anything) and you'll have a pretty good understanding on what setup to use to get the car to conform to your driving style.

Cy · Post by Cy » August 4th, 2006, 1:50 am

doesn't jacking up the rear tire pressure causing the tire to bow out, reducing the contact patch, induce oversteer?????

Nd4SpdSe · Post by **Nd4SpdSe** » August 13th, 2006, 12:16 am

I went again today, I had my fronts at 47psi and my rears down to around 25, and it worked well. I think i needed to add a bit more in the rear, cause the rear liked to kick out, it was great fun and I loved it!

Bochek · Post by **Bochek** » August 13th, 2006, 8:16 am

Cy wrote:doesn't jacking up the rear tire pressure causing the tire to bow out, reducing the contact patch, induce oversteer?????

actually no, less pressure will cause the tire to sort of roll under the rim decreasing the tread contacting the road, i had my fronts and about 42 psi (crappy motormaster tires) and they where still rolling to far, my rears where at 26 (goodyear allegra's) and they where allmost perfect.

Bochek