EXXEL Distributions
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read

Go Back   BMW M3 and BMW M4 Forum > BMW F80 M3 / F82 M4 Technical Topics > Wheels | Tires -- Sponsored by The Tire Rack

Post Reply
 
Thread Tools Search this Thread
      08-02-2014, 08:03 PM   #1
accce
Lieutenant
United_States
72
Rep
495
Posts

Drives: M4 SBM/BLK EXT CC Brakes
Join Date: May 2011
Location: MD

iTrader: (0)

Tire Pressure for the track

I always bump up the PSI for the track to stiffen up the sidewall. What PSI do you run tires at when your on the track?
Appreciate 0
      08-03-2014, 09:00 AM   #2
MaynardZed
Lieutenant Colonel
MaynardZed's Avatar
United_States
1231
Rep
1,789
Posts

Drives: wife crazy
Join Date: Jul 2014
Location: Phoenix

iTrader: (0)

Garage List
Quote:
Originally Posted by accce View Post
I always bump up the PSI for the track to stiffen up the sidewall. What PSI do you run tires at when your on the track?
Sorry, this is wrong. Pressures can increase by 5-7 psi between the start and end of a 15 minute track session. Tire heats up therefore gas expands which causes pressures to rise. If pressures get too high your car will feel like its on ice by the end of the session.

If anything I would let air out at the start of your track day. My guess with the weight of the F8X is maybe start the day with 32 psi all around and check the pressures as soon as you come off your first session. It might be around 36 after the session, and the 4 tires can vary depending on what type of track (left vs right), how aggressive you're driving, and how much understeer / oversteer your experiencing, and how hot it is that day.
Appreciate 0
      08-03-2014, 11:59 AM   #3
maxd23
Private First Class
United_States
29
Rep
100
Posts

Drives: Mk 7.5 GTI Audi R8
Join Date: May 2014
Location: Long Beach

iTrader: (0)

Yes, bumping up tire pressures is incorrect. In addition to what MaynardZed said above, you want softer sidewalls to increase grip.

I usually start at 32 psi cold for the first morning run and I check my pressures immediately after each run. Throughout the day I am constantly taking out air until the air/track temps start dropping. Usually last run of the day I have to add a couple psi all around.
Appreciate 0
      08-03-2014, 07:10 PM   #4
gthal
Major General
gthal's Avatar
Canada
1901
Rep
5,678
Posts

Drives: 2018 340i xDrive
Join Date: Jul 2007
Location: Canada

iTrader: (2)

I always start 5 to 6 psi less than normal and then gauge from there. To me, it's all about measuring sidewall rollover. Too much rollover and you increase pressure. None at all (that is, wear is not coming to the outer edge of the tread) or the car feels too unstable and I lower it a bit. If you are a baller and have a pyrometer to measure temp across the tread that's even better. Given the F82 is 32 psi, I will like start with 28 and see where that ends up and adjust from there.

Going above the normal street pressure that will only result in too much centre wear, less traction and a car that is way too darty.
__________________
2020 X3 M40i | Black | Current DD
2020 C8 Corvette | Z51 | Torch Red ... built and waiting for delivery
2016 M2 | Long Beach Blue | 6MT
2015 M4 | Austin Yellow | DCT
2012 MB C63AMG | 2011 E92 M3 | 2010 E92 M3
Appreciate 0
      08-03-2014, 08:43 PM   #5
accce
Lieutenant
United_States
72
Rep
495
Posts

Drives: M4 SBM/BLK EXT CC Brakes
Join Date: May 2011
Location: MD

iTrader: (0)

Thx I am glad I asked!
Appreciate 0
      08-03-2014, 08:52 PM   #6
TomTarzian
Private First Class
United_States
26
Rep
130
Posts

Drives: 2021 Porsche Macan Turbo
Join Date: Jan 2007
Location: In Mass

iTrader: (0)

For track use, Donnie Isley, instructor at the Performance Center, recommends keeping the F80/82 (hot) tire pressures below 36 psi at all times. One of his colleagues suggested starting at 29(f) and 31(r) psi.

Last edited by TomTarzian; 08-04-2014 at 10:34 AM..
Appreciate 2
      08-03-2014, 09:23 PM   #7
FTS
Enjoying driving
FTS's Avatar
United_States
388
Rep
1,169
Posts

Drives: 645
Join Date: May 2009
Location: MD

iTrader: (0)

Wouldn't the hot pressures depend on the tire compound used?
Appreciate 1
CAOZKAN98.00
      08-04-2014, 10:34 AM   #8
TomTarzian
Private First Class
United_States
26
Rep
130
Posts

Drives: 2021 Porsche Macan Turbo
Join Date: Jan 2007
Location: In Mass

iTrader: (0)

Donnie was referring to the OEM Michelin Pilot Super Sports. He spent a day with an M4 at VIR recently.
Appreciate 0
      08-04-2014, 11:20 AM   #9
FTS
Enjoying driving
FTS's Avatar
United_States
388
Rep
1,169
Posts

Drives: 645
Join Date: May 2009
Location: MD

iTrader: (0)

spot on, I don't know any Michelins that like hot pressures over 36-37, same with Toyos, but Pirellis and HoHos seem to be different.
Appreciate 0
      08-04-2014, 11:24 AM   #10
SteveSpy
BMW Fanatic
SteveSpy's Avatar
United_States
374
Rep
1,413
Posts

Drives: 2020 X3 M
Join Date: Jun 2014
Location: Austin, TX

iTrader: (0)

Garage List
2018 X3 M40i  [0.00]
When I was on the track here in Austin driving a 458 Italia the tire pressure light was on. I showed it to the instructor and he said that they take air out of the tires for track racing and that's why there's a warning.
__________________
SteveSpy
Current Ride: 2020 X3 M
Appreciate 0
      05-22-2016, 08:00 AM   #11
poor-sha
Enlisted Member
17
Rep
32
Posts

Drives: 2016 M3
Join Date: Apr 2016
Location: NoVA

iTrader: (0)

Given that this thread is nearly 2 years old I figured there might be some more experience with the F80 on track. What are folks using for starting and target hot temps with the stock MPSS?

I just completed my first track event with this car and started at 31 all the way around but the fronts were up to 48 PSI before the first session was over so I started dropping pressures. I ended up dropping to around 26 PSI starting pressures which is typically where we start the Corvettes on MPSS run flats. That usually brought me in the 32-26 PSI hot pressures but saw a ton of sidewall roll-over and corded the outer edge of the front tires in 2 days.

Since this isn't my primary track car I plan on sticking with the MPSS when I go to the track but can't afford to run through a set of fronts in a weekend. Should I just start at 32 PSI and deal with the high pressures and lack of grip? I surprised both by how much the pressure climbed in this car and how much the sidewall rolled over.
Appreciate 0
      05-22-2016, 10:06 AM   #12
DC-T
Lieutenant
DC-T's Avatar
357
Rep
469
Posts

Drives: F10 M5/Golf R/Amarok
Join Date: Jul 2015
Location: Johannesburg, South Africa

iTrader: (0)

depends what wheels I'm running...
Appreciate 0
      05-23-2016, 10:35 AM   #13
Brasko
#LSBM3
Brasko's Avatar
No_Country
1418
Rep
1,973
Posts

Drives: 2016 BMW M3
Join Date: Feb 2015
Location: Oregon / Florida

iTrader: (4)

Garage List
I posted this here, but thought I'd share since this thread aligns with my experience.


I've been experimenting with this for my upcoming road trip as well as daily driving and track days.

This is the method I follow:
  1. Drive car several miles to get tires up to temperature.
  2. Park vehicle and use a quality digital tire pressure gauge to check pressure. I use a Michelin tire pressure gauge.
  3. Adjust pressure as needed so that all tires are at equal pressure.
  4. Drive vehicle a few miles to get tires back up to temperature.
  5. Compare results with onboard tire pressure monitor.

Ultimately, you would want to balance the tire pressure so that when the vehicle is under load, the tire air pressure remains as equal as possible. For instance, my current set up is the following. This allows room for extreme cases (long road trips, spirited driving, etc.) were the tires are building heat and the air pressure rises to remain under or at the 51psi max pressure recommended by the Continental Tires.


Right front tire: 47.6psi
Right rear tire: 47.3

Left front tire: 47.9psi
Left rear tire: 47.6


Looking at these values you can see that when my M3 is at load the tire pressure remains pretty equal with the lowest value (right rear) 0.3psi under the average value versus the highest tire pressure (front left) at 0.3psi over the average. The added weight from the driver (myself) accounts for the variance. Some fine tuning might bring these values even closer.


**These examples are based on an F80 M3 with a driver at 5'10, 165lbs. Full tank of gas, and no other cargo. Wheels are 19" with OEM Continental Tires. Your experience may vary.
__________________


/// M3
Appreciate 0
      05-23-2016, 05:12 PM   #14
poor-sha
Enlisted Member
17
Rep
32
Posts

Drives: 2016 M3
Join Date: Apr 2016
Location: NoVA

iTrader: (0)

Quote:
Originally Posted by DC-T View Post
depends what wheels I'm running...
Stock 19" wheels and currently on stock sizes (I just found the thread on folks running 275/295 after I bought new fronts).
Appreciate 0
      10-15-2022, 04:48 PM   #15
2sporty
First Lieutenant
Germany
244
Rep
356
Posts

Drives: bmw
Join Date: Jul 2014
Location: Munich

iTrader: (0)

Quote:
Originally Posted by Brasko View Post
I posted this here, but thought I'd share since this thread aligns with my experience.


I've been experimenting with this for my upcoming road trip as well as daily driving and track days.

This is the method I follow:
  1. Drive car several miles to get tires up to temperature.
  2. Park vehicle and use a quality digital tire pressure gauge to check pressure. I use a Michelin tire pressure gauge.
  3. Adjust pressure as needed so that all tires are at equal pressure.
  4. Drive vehicle a few miles to get tires back up to temperature.
  5. Compare results with onboard tire pressure monitor.

Ultimately, you would want to balance the tire pressure so that when the vehicle is under load, the tire air pressure remains as equal as possible. For instance, my current set up is the following. This allows room for extreme cases (long road trips, spirited driving, etc.) were the tires are building heat and the air pressure rises to remain under or at the 51psi max pressure recommended by the Continental Tires.


Right front tire: 47.6psi
Right rear tire: 47.3

Left front tire: 47.9psi
Left rear tire: 47.6


Looking at these values you can see that when my M3 is at load the tire pressure remains pretty equal with the lowest value (right rear) 0.3psi under the average value versus the highest tire pressure (front left) at 0.3psi over the average. The added weight from the driver (myself) accounts for the variance. Some fine tuning might bring these values even closer.


**These examples are based on an F80 M3 with a driver at 5'10, 165lbs. Full tank of gas, and no other cargo. Wheels are 19" with OEM Continental Tires. Your experience may vary.
The guy asked for tire pressures at the track, not for a road trip. This is insanely bad advice for the track. After I clicked the link of your tire pressure gauge, I took your entire post with a grain of salt.
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 03:17 PM.




f80post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST