Novice tire pressure question

[D.DeVo]

I am tracking my GT350 at Summit Point, West Virginia, this weekend. I've got 2,000 miles on my car. I just checked the tire pressure & all tires are at 36 psi. Door frame shows psi should be 32 psi. What is best for two days on the track?

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[SVTDSM]

From the supplement manual...

 

[D.DeVo]

Yah, I've read the manual. I was just looking for some advise from someone that has had track experience.

 

[Trackaholic]

I usually take out a couple PSI when I arrive, a couple more after the first session, then maybe a couple more after the second. By then things have usually stabilized. I'm looking to keep the tires @ ~35 PSI HOT, which is roughly 28 PSI cold. It's tough for me to know exactly since I'm usually checking pressures with the tires at least warm, so that's why I end up doing things in increments.

And I've driven several hundred miles since my last track day and haven't bothered to refill the tires. Am currently running about 31-32 PSI when warm.

-T

 

[svttim]

Yah, I've read the manual. I was just looking for some advise from someone that has had track experience.

No one has more track time then the people at Ford performance.

 

[10splaya22]

Yah, I've read the manual. I was just looking for some advise from someone that has had track experience.

Well Ford performance has more track experience with the car then everyone on this forums combined. I would trust them.

 

[Zitrosounds]

I followed the FP recommendations. Checked Tire pressure before going out on each session. 28PSI when cold 35PSI when hot. The car on the track was insane! I was really blown away. When I left the vent I forgot to set my tires to 32psi and the car wanted to crab, or tram whatever you want to call it. tramming a little. So if you drive to the event, set to factory pressure before you leave.

 

[RadBOSS]

Hmmm, interesting. Back in the day when I ran my 69 BOSS 302 with racing tires SCCA Solo I, I believe we were required to 40 psi. Believe it had to do with the high aspect ratio tires of the day (like 60 series) and the ability to peel the bead off the rim and loose all the air. Not fun to happen. It makes sense that with the lower aspect tires and taller rims, there is more resistance to peeling off the the rim during hard corning. So 32 hot may be entirely adequate. Novice drivers may have a tendency to understeer entering a corner aggravating the situation. Even running Solo 2 we were required to run at least 40 psi.

I did find the chassis setting sheet in the manuals for the 2016

 

[RadBOSS]

Hmmm, interesting. Back in the day when I ran my 69 BOSS 302 with racing tires SCCA Solo I, I believe we were required to 40 psi. Believe it had to do with the high aspect ratio tires of the day (like 60 series) and the ability to peel the bead off the rim and loose all the air. Not fun to happen. It makes sense that with the lower aspect tires and taller rims, there is more resistance to peeling off the the rim during hard corning. So 32 hot may be entirely adequate. Novice drivers may have a tendency to understeer entering a corner aggravating the situation. Even running Solo 2 we were required to run at least 40 psi.

I did not find the chassis setting sheet in the manuals for the 2016

 

[CSL]

I have found the Ford recommendations for tire pressures to be pretty spot on for both the street and track.

 

[Hack]

For autocross you might want the pressure a little higher compared to a road course event. Ford's recommendations are for road courses. During autocross there's typically not enough time actually moving (versus waiting) for the tires to get very warm.

 

[nastang87xx]

For autocross you might want the pressure a little higher compared to a road course event. Ford's recommendations are for road courses. During autocross there's typically not enough time actually moving (versus waiting) for the tires to get very warm.

Milwaukee, WI here, I was emptying to 28 PSI and after my runs I'd be at 30 - 31. Temps were maybe mid to high 70's. 28 seemed about right.

 

[Bossing]

I do 28-29 psi cold. Plus it's also depending on how hard you will drive ypur car and the ambient temps outside. Usually this would equate to 34-35 hot. I usually drop mine to 29psi at first and then check the hot temps after each session.... drop the psi each time if needed.

 

[Hack]

Milwaukee, WI here, I was emptying to 28 PSI and after my runs I'd be at 30 - 31. Temps were maybe mid to high 70's. 28 seemed about right.

Your choice of course. Remember that you started at 28 and only achieved 30-31 at the end. So midway through the course you would probably be at 29.

 

[oldmachguy]

You're actually in a good spot, just starting out.

Keep a log of ambient conditions (especially temperature) for each run session.

Set your tire pressures cold, before doing any run sessions. Start with Ford specs.

Log your tire pressures immediately before each session, and immediately after each session. You will learn to "trim" back your pressures after each run, depending on how the car turns in, brakes, and understeers / oversteers.

Make notes for each session: observations about the track (bumps, dangerous spots), observations about any unusual events (loss of control, offs, etc.), your impressions about the car's behavior, your instructor's comments, etc.

Like others mentioned, "optimum" pressures depend on MANY factors, including the tire itself, the track, ambient conditions, how you drive it, etc.

Patience. Practice. Data. Practice. Data. Patience.

SAFETY, SAFETY, SAFETY - even in the pits.

-- Take pics, especially of you and your friends, AND ENJOY EVERY MINUTE OF IT!

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