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Old 04-20-2017, 03:14 PM   #1
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Ideal PSI for Potenza RE71R

Hey guys, my first track day is coming up quick and I wanted to get some feedback from experienced guys on what the ideal hot and cold PSI for my tires are? I'm running Potenza RE71Rs 245/40/17 on RPF1s all around. If it matters, the track is Streets of Willow so more cornering than straights.
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Old 04-20-2017, 03:30 PM   #2
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A few weeks back I asked about it in the STX setup thread, got two people suggesting 28psi hot for autox. I've run 32 and all the way up to 37 psi and the tire still feels solid up there, you just won't be maximizing grip.

http://www.ft86club.com/forums/showp...postcount=2717
http://www.ft86club.com/forums/showp...postcount=2720

Track will be different, but I'd suspect their happy place may be fastest <30 psi.

They were pretty fun up at 37 psi though, slippery but predictable.
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Old 04-20-2017, 03:31 PM   #3
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I have the same setup w/ -3F and -2.2R camber. I seem to like ~34-36PSI HOT, it gets pretty damn close to the contact patch triangle indicators. Cold PSI kind of depends on ambient temperature; I usually start at ~30-32 COLD and then bleed out when checking pressures immediately after a session.
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Old 04-20-2017, 03:49 PM   #4
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Fill up your tires to the psi suggested on the door placard. Then use a white grease pencil and draw a single line on each wheel from high on the sidewall to just over the tire shoulder on to the tread.

Do some runs get your tires warm in a situation where you want the performance out of the tires. Check the lines you drew on the shoulder of your tires. You don't want to run on the sidewall, but you want to take advantage of all of your tread too and you can tell if you are under or over inflated by looking at the wear of the grease pencil marks. If the sidewall is rolling too much due to under inflation the grease pencil will be worn off the sidewall. If you are pumped up too much, the grease pencil near the shoulder will be untouched.

I did this at an autocross and I narrowed the psi I needed down to a cold 29psi on stockers and stock camber.
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Old 04-20-2017, 05:20 PM   #5
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From autocross, 26-32psi hot is the happy place for RE71R. Track may require a little more.

The triangles are only indicators for where the wear bars are located. I wouldn't rely on those for checking if you have even wear. That's what a pyrometer is for.
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Old 04-20-2017, 05:52 PM   #6
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I did this at an autocross and I narrowed the psi I needed down to a cold 29psi on stockers and stock camber.
For RE71R's?

I tried the chalk/sidewall method and ended up at like 40 psi, I don't use that method anymore, but I might be a bit of a dunce.

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Old 04-20-2017, 08:39 PM   #7
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cold 29psi on stockers
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Old 04-20-2017, 11:13 PM   #8
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IMO, tire pressures has to do with tire size in relation to wheel width. I would pay attention to that as well and not so much as the tire size in general.
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Old 04-21-2017, 01:04 PM   #9
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Most people in autocross have found 29psi front and slightly less rear to be ideal. For track you have to take into account that your pressures will rise while you're out there and you won't have a chance to just pull over and fix them. If you want your pressures to be ideal for most of your session you should start a little low (27 front / 24 rear would work) and then get some heat into them as you go. You'd likely end up running around 32f/29r by the mid point of your session.
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