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Old 02-24-2015, 03:19 PM   #18
7thgear
i'm sorry, what?
 
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Quote:
Originally Posted by renfield90 View Post
. Regardless of whether you think a sufficiently rolled over tire can flip a car, the physics of higher tire pressures creating more grip are unchanged.
From the site that you quoted (which I revisit every so often)


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From all this, we can assume the following:
  1. A tire will gain grip with increasing tire pressure until the internal pressure overcomes the strength of the carcass portions that keep the tire cylindrical, at which point the tire will start losing grip;
  2. A tire with a fairly rigid construction (a DOT-approved tire) will want more total pressure than a tire with a floppy construction (race slick);
  3. A wide tire (with a large unsupported beam section across the tread section area) will stand less total pressure than a narrow tire; and
  4. A soft tire will need less pressure than a hard tire.
And this is pretty much what is observed in the wild. A wide, floppy, soft, and sticky race slick might use 15 PSI, but a narrow, stiff, hard, and smooth OEM street tire might use 55 PSI.

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this is why I'm fairly comfortable running 27~28 psi on a 235 R1R on a 2800 lb car. But will run higher on other tires like the RS3 or ZII




having said that, 22 psi on any street tire is suspicious..... No way that's enough air to support the carcass under comp use, it is bound to deform.
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