|
Tracking / Autocross / HPDE / Drifting What these cars were built for! |
|
Thread Tools | Search this Thread |
04-20-2017, 03:14 PM | #1 |
Member
Join Date: Jul 2015
Drives: 2014 Scion FRS Track Build
Location: Southern California
Posts: 74
Thanks: 9
Thanked 13 Times in 9 Posts
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
|
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.
Thanks! |
04-20-2017, 03:30 PM | #2 |
-
Join Date: Nov 2012
Drives: '13 FRS - STX
Location: SF Bay Area
Posts: 10,376
Thanks: 13,769
Thanked 9,495 Times in 5,008 Posts
Mentioned: 94 Post(s)
Tagged: 3 Thread(s)
|
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. |
The Following User Says Thank You to strat61caster For This Useful Post: | byun (04-30-2017) |
04-20-2017, 03:31 PM | #3 |
Member
Join Date: Feb 2016
Drives: '17 Camaro SS 1LE
Location: NYC
Posts: 61
Thanks: 17
Thanked 44 Times in 25 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
|
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.
|
04-20-2017, 03:49 PM | #4 |
Huge E85 fan!
Join Date: May 2016
Drives: 2016 Scion FRS
Location: Tampa, FL, USA
Posts: 1,850
Thanks: 539
Thanked 1,010 Times in 605 Posts
Mentioned: 32 Post(s)
Tagged: 0 Thread(s)
|
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. |
The Following 2 Users Say Thank You to guybo For This Useful Post: | JazzleSAURUS (04-20-2017), sato (04-20-2017) |
04-20-2017, 05:20 PM | #5 |
Senior Member
Join Date: Jan 2014
Drives: BRZ
Location: Bay Area, CA
Posts: 197
Thanks: 104
Thanked 123 Times in 70 Posts
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
|
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. |
The Following 4 Users Say Thank You to AFRichZC6 For This Useful Post: |
04-20-2017, 05:52 PM | #6 | |
-
Join Date: Nov 2012
Drives: '13 FRS - STX
Location: SF Bay Area
Posts: 10,376
Thanks: 13,769
Thanked 9,495 Times in 5,008 Posts
Mentioned: 94 Post(s)
Tagged: 3 Thread(s)
|
Quote:
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. |
|
04-20-2017, 08:39 PM | #7 | |
Huge E85 fan!
Join Date: May 2016
Drives: 2016 Scion FRS
Location: Tampa, FL, USA
Posts: 1,850
Thanks: 539
Thanked 1,010 Times in 605 Posts
Mentioned: 32 Post(s)
Tagged: 0 Thread(s)
|
in case you missed it
Quote:
|
|
04-20-2017, 11:13 PM | #8 |
Member
Join Date: Feb 2017
Drives: 2014 Scion FR-S
Location: Southern California
Posts: 21
Thanks: 0
Thanked 27 Times in 13 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
|
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.
|
The Following User Says Thank You to jwisjw For This Useful Post: | AFRichZC6 (04-21-2017) |
04-21-2017, 01:04 PM | #9 |
Custom User Title
|
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.
__________________
LOCUST 2015 FR-S (STX) and 2012 Evo X MR Instagram: LocustAutoX Sponsors:DSGPerformance Drift Office Evil Apex Racing |
|
|
Tags |
autocross, psi, tires, track |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
FS: Enkei RPF1 with Potenza RE71R | RedFR-s | Canada Classifieds | 12 | 08-11-2016 03:52 PM |
AD08 or RE71R | tofurun | Wheels | Tires | Spacers | Hub -- Sponsored by The Tire Rack | 12 | 08-04-2016 10:26 AM |
FS: 17x9 Enkei RPF1 & 245/40 Potenza RE71R | ksconekiller | Wheels and Tires | 11 | 01-04-2016 01:22 PM |
Enkei RPF1 17x9 +45 with 245/40 Potenza RE71R | ksconekiller | Wheels and Tires | 1 | 10-27-2015 10:23 PM |
Bridgestone Potenza RE71R Stagger | funcheung | Canada Classifieds | 0 | 08-19-2015 04:43 PM |