Notices
991 GT3, GT3RS, GT2RS and 911R 2012-2019
Sponsored by:
Sponsored by:

Track Tire Pressure

Thread Tools
 
Search this Thread
 
Old 07-25-2017, 09:11 AM
  #1  
Mach5gsxr
Advanced
Thread Starter
 
Mach5gsxr's Avatar
 
Join Date: Jun 2017
Posts: 90
Received 13 Likes on 12 Posts
Default Track Tire Pressure

What are you guys setting your cold tire pressure for Sport Cup 2s at the track? I'm thinking 26 front and 30 rear, I had them at 29/33 which I think was a mistake for the track.
Old 07-25-2017, 10:26 AM
  #2  
kfmcmahon
Three Wheelin'
 
kfmcmahon's Avatar
 
Join Date: Feb 2013
Location: East Amherst, NY
Posts: 1,984
Received 110 Likes on 57 Posts
Default





this is from Michelin website

TPMS doesn't like cold
pressure under 26 if you are using the "Circuits" mode

The best thing to do if the pressures get above 35 is to keep a pressure gauge in the frunk then, hot pit and adjust pressures - takes 2 minutesj

Last edited by kfmcmahon; 07-25-2017 at 10:51 AM.
Old 07-25-2017, 10:33 AM
  #3  
TRAKCAR
Rennlist Member
 
TRAKCAR's Avatar
 
Join Date: Jan 2008
Location: S. Florida
Posts: 29,336
Received 1,586 Likes on 734 Posts
Default

33 front is too high for me.
I met a couple of Michelin support teams on track doing my Euro Delivery and they told me 29F 33R and that's the cold psi in the door, so easy to remember. I try to aim for 30 all around because if I cant get them to 29F, 28F doesn't feel right. Rear just needs to stay under 33R but 31 is better.
Old 07-25-2017, 10:48 AM
  #4  
kfmcmahon
Three Wheelin'
 
kfmcmahon's Avatar
 
Join Date: Feb 2013
Location: East Amherst, NY
Posts: 1,984
Received 110 Likes on 57 Posts
Default

Originally Posted by TRAKCAR
33 front is too high for me.
I met a couple of Michelin support teams on track doing my Euro Delivery and they told me 29F 33R and that's the cold psi in the door, so easy to remember. I try to aim for 30 all around because if I cant get them to 29F, 28F doesn't feel right. Rear just needs to stay under 33R but 31 is better.

yeah, I think everyone has a different "feel" for what pressures are best for their driving style... most often my best laps are at 32-33f and 34-35r, but car type, engine location, suspension and alignment settings I would expect, would all influence that feeling
Old 07-25-2017, 11:39 AM
  #5  
TRAKCAR
Rennlist Member
 
TRAKCAR's Avatar
 
Join Date: Jan 2008
Location: S. Florida
Posts: 29,336
Received 1,586 Likes on 734 Posts
Default

And depends on grip level asphalt and ambient temps as well...
Old 07-25-2017, 03:36 PM
  #6  
Mach5gsxr
Advanced
Thread Starter
 
Mach5gsxr's Avatar
 
Join Date: Jun 2017
Posts: 90
Received 13 Likes on 12 Posts
Default

Trying 24/28 cold next time, I like an oversteer.
Old 07-26-2017, 02:45 AM
  #7  
CDinSing
Rennlist Member
 
CDinSing's Avatar
 
Join Date: Jun 2012
Location: Melbourne, Florida
Posts: 747
Received 168 Likes on 75 Posts
Default

I see 6-8 psi increase from heat build, so morning cold pressures are 24/26 for a 30/32 hot pressure. I find 30-32 give me a good balanced feel in the car. Over 34 and the car just slides and feels greasy.
Old 07-26-2017, 07:30 AM
  #8  
RFGGT3
Burning Brakes
 
RFGGT3's Avatar
 
Join Date: Oct 2014
Location: Longboat Key, FL
Posts: 1,047
Received 12 Likes on 9 Posts
Default

Originally Posted by CDinSing
I see 6-8 psi increase from heat build, so morning cold pressures are 24/26 for a 30/32 hot pressure. I find 30-32 give me a good balanced feel in the car. Over 34 and the car just slides and feels greasy.
Ditto.
Old 07-26-2017, 09:20 AM
  #9  
kfmcmahon
Three Wheelin'
 
kfmcmahon's Avatar
 
Join Date: Feb 2013
Location: East Amherst, NY
Posts: 1,984
Received 110 Likes on 57 Posts
Default

Or try a pyrometer probe (not IR) to be more accurate, but you need a buddy to do it while tires are still hot, especially if you have 5/6 pint harnesses



this is from and old Motortrend article GT3RSat the bottom

Old 07-26-2017, 10:05 AM
  #10  
Cookie991
Intermediate
 
Cookie991's Avatar
 
Join Date: Sep 2014
Location: Seattle, WA
Posts: 41
Likes: 0
Received 0 Likes on 0 Posts
Default

I'm generally starting at 24/25 Cold then resetting to 29/30 hot. Pretty even tire temperature at around 160F depending on track temp. Last track day on a warm track 28/30 hot seemed to work well on older cup2s to combat understeer, but it takes about 3-4 laps to get up to temp.

I agree with the consensus, higher than 34 on the rear and things get gnarly, much worse then the GT3.

Every track day there is always someone on Cup 2s running 35+ wondering why they're struggling for grip...
Old 07-26-2017, 10:14 AM
  #11  
Manifold
Rennlist Member
 
Manifold's Avatar
 
Join Date: May 2012
Location: Mid-Atlantic (on land, not in the middle of the ocean)
Posts: 12,398
Received 3,750 Likes on 2,174 Posts
Default

Should be around 32 or 33 hot F and R, but it depends somewhat on your cambers and alignment. Probably best not to lean on the tires too much until pressures are at least in the high 20s, so be careful when starting cold in mid 20s.
Old 04-13-2018, 02:59 PM
  #12  
manitou202
Burning Brakes
 
manitou202's Avatar
 
Join Date: Aug 2014
Location: Manitou Springs, CO
Posts: 1,043
Received 406 Likes on 158 Posts
Default

I have my first two track days this weekend with my .2GT3.

Two questions related to tire pressures.

1. Has anyone run at the track with the Dunlops? Use similar pressure and the Cup2's?

2. It's going to be cold on Saturday (30F in the morning and 50F in the afternoon). I haven't run at the track in this cold of weather so I plan on taking it very easy. However, should I be adjusting my tire pressure because it's so cold in the morning?

Sorry if these are newbie questions.

Thanks for any help.
Old 04-13-2018, 03:04 PM
  #13  
TRAKCAR
Rennlist Member
 
TRAKCAR's Avatar
 
Join Date: Jan 2008
Location: S. Florida
Posts: 29,336
Received 1,586 Likes on 734 Posts
Default

1. Yes and yes, pretty much the same.
Just start a little too high the first session, so maybe 26 all around cold. You will be too high when you come off the track but just bleed them down to say 32-34 This way you are definitely good, a bit on the high side but that's OK.
Old 04-13-2018, 03:14 PM
  #14  
manitou202
Burning Brakes
 
manitou202's Avatar
 
Join Date: Aug 2014
Location: Manitou Springs, CO
Posts: 1,043
Received 406 Likes on 158 Posts
Default

Originally Posted by TRAKCAR
1. Yes and yes, pretty much the same.
Just start a little too high the first session, so maybe 26 all around cold. You will be too high when you come off the track but just bleed them down to say 32-34 This way you are definitely good, a bit on the high side but that's OK.
Thanks TRAKCAR!
Old 04-13-2018, 03:30 PM
  #15  
mwar99
Three Wheelin'
 
mwar99's Avatar
 
Join Date: Jan 2014
Location: Northern NJ
Posts: 1,726
Received 285 Likes on 178 Posts
Default

I wouldn't trust that article graphic. 37 in the back on a GT3 will have you sliding through the corners (unless that's what you want). Any time my rears go over 35 it starts to tend to want to slide around. I can't imagine 37 would be fun unless you want to drift the corners.


Quick Reply: Track Tire Pressure



All times are GMT -3. The time now is 03:43 PM.