Tire Pressure, big or no difference?
#1
Le Mans Master
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St. Jude Donor '03 & '05
Tire Pressure, big or no difference?
I have noticed many people recommend upping tire pressure for autocross. I have fairly good street tires, BFG KD's, and when I mark them with shoe polish, the sides are never worn away, making me feel like the pressure I run 33f 32r, is okay. I was looking at some photos of a recent autocross and comparing my pics of my 93(base suspension with ZO7 sway bars, QA1 shocks), in the same turn types or same turn, of a 07 ZO6, C5 with better tires wheels and an 06 Z51 C6 to see if I could see any rollover within the tire, and there was very little.
So, would I benefit by upping my pressure. I know the ZO6 and Z51 have much better suspensions (Z51 stock/stock tires and ZO6 + A6 Hoosiers), but its all I have for comaprisons.
So, would I benefit by upping my pressure. I know the ZO6 and Z51 have much better suspensions (Z51 stock/stock tires and ZO6 + A6 Hoosiers), but its all I have for comaprisons.
#2
Melting Slicks
Shoe polish really tells you next to nothing. You need a pyrometer to check tire temps across the surface of the tire. Once you see the temps, then you can adjust.
The reason for upping the pressures during an Auto-X is that a tire has a sweet spot pressure. If you go to a big track, where you can do lots of laps and build some heat, that will raise the pressure automatically. With an auto-X, you only run every once in a while and tires will cool off by the time you run again. If you start at the 'optium' pressure though, theoretically, the car will handle better and your lap times will be better.
Before you ask, every tire/car/driver is different so no, there's not one perfect pressure for everyone. That's what you have to find out.
The reason for upping the pressures during an Auto-X is that a tire has a sweet spot pressure. If you go to a big track, where you can do lots of laps and build some heat, that will raise the pressure automatically. With an auto-X, you only run every once in a while and tires will cool off by the time you run again. If you start at the 'optium' pressure though, theoretically, the car will handle better and your lap times will be better.
Before you ask, every tire/car/driver is different so no, there's not one perfect pressure for everyone. That's what you have to find out.
#6
Le Mans Master
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I had BFG KD's on my car. I had 275R17's on the front with 1 deg of negative camber, 315R17's on the rear (I don't recall the rear camber but probably around -0.75 deg). I took some tire temps and found 34 front, 33 rear worked great. These are cold pressures.
Oh yah, I have a little toe out on the front and a little bit more toe in on the rear.
Oh yah, I have a little toe out on the front and a little bit more toe in on the rear.
#9
Le Mans Master
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St. Jude Donor '03 & '05
I had BFG KD's on my car. I had 275R17's on the front with 1 deg of negative camber, 315R17's on the rear (I don't recall the rear camber but probably around -0.75 deg). I took some tire temps and found 34 front, 33 rear worked great. These are cold pressures.
Oh yah, I have a little toe out on the front and a little bit more toe in on the rear.
Oh yah, I have a little toe out on the front and a little bit more toe in on the rear.
#11
Pro