Jump to content

Photo

What Are My Tire Temps Telling Me?

- - - - -

  • Please log in to reply
22 replies to this topic

#1
bmarshall1

bmarshall1

    Member

  • Members
  • PipPipPip
  • 226 posts
  • Location:United States
  • Region:SW Florida
  • Car Year:1999
  • Car Number:23

New tire probe 

 

Sebring long course, 2nd morning run, sunny, clear, 82 deg F, 11:00am.  Hoosiers at end of life, mid/bottom third driver.

 

Outside   -   Inside   -   Outside

 

162/166/181 - 174/160/140   FRONT

 

165/168/171 - 150/160/173  REAR

 

 

Are tire temps overrated or a essential tool to adjust camber/toe?



#2
Steve Scheifler

Steve Scheifler

    member

  • Members
  • PipPipPipPipPip
  • 2,568 posts
  • Location:St. Louis
At a glance your example could say as much about the driving as the car, but that’s assuming the driver came in as hot as possible and temps were taken quickly. That can be challenging to impossible so you need to get a feel for mental compensation based on circumstances.

I have no experience at Sebring, hopefully someone who does will share comparable data, so I probably can’t offer better than generic info you can find anywhere on the web. But back to my at-glance impressions:

They are all too low whether cooling before checked, being underworked, or too old and hard to build heat short of excessive sliding.

Left side distribution looks good, almost too good. An under-cambered but also under-driven tire will appear to be using the full width of a tire, as will an optimally set and driven one, albeit at lower temps (see above). Ambient vs track surface temps will impact which part of the tire cools at what rate coming in but your example is not at any extreme so nothing jumps out on that side.

Right Front spread is a bit high but also lowest overall so possibly underworked and/or over cambered, the inside taking too much of the load.

Right Rear is next lowest overall but the spread is reversed relative to the others. All the other possible variables aside, that specifically needs to be understood. There may be an explanation that doesn’t prompt a change, but it needs a look. Did it loose camber, or get toed in? Unlikely a tire issue but not impossible.

All too generic without more information though, needs more context. Remind us what you believe your alignment to be, and describe the in-lap and temp taking procedure. How much do your pressures rise during a session from ambient on a 80 degree day? Filled with plain air I assume? Typical humidity when initially mounting & filling tires?
Bona fide - A bonafide Spec Miata driver

#3
Tom Hampton

Tom Hampton

    Egregious Member

  • SMembers
  • PipPipPipPipPip
  • 2,058 posts
  • Location:Mckinney, tx
  • Region:South west
  • Car Year:1992
  • Car Number:41
My primary thought as a fellow midpack driver a little closer to the front...

Until you have maximized the data from tire PRESSURE... Temps (esp. Out, mid, in) are silly. As Steve pointed out "temps" require real hot measures,as quick as you can get off track...not AFTER the checker and a cooldown. You have to come in under green from a hot lap.

Also as Steve noted... Those temps are way too cold. You should me closer to 200. If your not at 200 or close the data is useless.

-tch
Build: www.tomhampton.info

video: vimeo.com/tomhampton

Support: X-Factor Racing

 

I didn't lose, I just got outspent!

Beta-Tester - Assisted us with beta testing the website. Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver

#4
Jamz14

Jamz14

    Veteran Member

  • Members
  • PipPipPipPipPip
  • 1,271 posts
  • Location:California
I'll say it more simply than Tom or Steve. They are telling you nothing about the driver or the car.

My temp probe is the most useless tool I own. Unless you are data logging temps, you are learning nothing from the info. The best you can hope for is to learn something about the last corner before taking probe temps.

So there you have it: 3 people that often disagree, agree that nothing is being learned by your numbers.
  • Tom Hampton likes this
Broken record - You are starting to sound like a broken record. Donor - Made PayPal donation Sponsor / Advertiser - Site sponsor / advertiser... support these guys! Novel Approach - When a paragraph simply won't do... Make it Rain - Made Paypal donation of $100+ Bona fide - A bonafide Spec Miata driver

#5
Jim Drago

Jim Drago

    East Street Racing / 2 Time National Champion

  • Administrators
  • 6,416 posts
  • Location:Memphis, Tn
  • Region:Mid South
  • Car Year:2005
  • Car Number:2

I'll say it more simply than Tom or Steve. They are telling you nothing about the driver or the car.

My temp probe is the most useless tool I own. Unless you are data logging temps, you are learning nothing from the info. The best you can hope for is to learn something about the last corner before taking probe temps.

So there you have it: 3 people that often disagree, agree that nothing is being learned by your numbers.

four :)


  • Tom Hampton likes this

East Street Auto Parts
Jim@Eaststreet.com
800 700 9080

NASA Champs Winner - NASA Champs Winner Hoosier Super Tour points Champion - Hoosier Super Tour points Champion ARRC Champion - Won the ARRC Race in a Spec Miata Series Champ - Won a points based series in a Spec Miata BFG Supertour Winner - Majors Winner - Circuit of the Americas Winner - We have a Winnah! - Won their 1st race... Congratulations! June Sprints winner  - June Sprints winner June Sprints winner  - June Sprints winner June Sprints winner  - June Sprints winner June Sprints winner  - June Sprints winner SCCA National Champion - Won SCCA Runoffs at Road America SCCA National Champion - Won SCCA Runoffs at Road America

#6
Bench Racer

Bench Racer

    Different strokes for different folks : )

  • Members
  • PipPipPipPipPip
  • 5,426 posts
  • Location:Wauwatosa, WI
  • Region:Milwaukee
  • Car Year:1990
  • Car Number:14

four :)

Is that "four" the same as a golf course four, protect yourself something's going to hit you. :rotfl:  :bigsquaregrin:


  • Jim Drago likes this
Broken record - You are starting to sound like a broken record. Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver

#7
bmarshall1

bmarshall1

    Member

  • Members
  • PipPipPip
  • 226 posts
  • Location:United States
  • Region:SW Florida
  • Car Year:1999
  • Car Number:23

LOL at least everyone agrees- OK, here's a little more info, I'm not sure how I missed all these answers until now.

 

I was pit crew for a friend on his 99.  Hot lap from green directly to pit row so no time between being at speed to measurements.  Mid-pack driver, and does not push his tires as hard as a front runner. would  Hoosiers near end of life, likely a little hard as well.  He has a tendency to go in a little easier on brakes and power out faster (than me) even though we get roughly the same lap times.  Starting pressure 33 lbs.  The final corner is a back straight into a right hander going from top of 4th, then braking, coming out at top of second gear then straight to pit row

 

I's very possible I transposed the RR temp numbers.

 

The main thing I get from the post is that tire temps aren't telling me much.  I don't currently know his camber toe settings (but will get them) (maybe 3.4/3.2 F/R).

 

Knowing that the goal is closer to 200 degree is to me a big tell that they aren't being pushed hard enough to heat up properly.



#8
Tom Hampton

Tom Hampton

    Egregious Member

  • SMembers
  • PipPipPipPipPip
  • 2,058 posts
  • Location:Mckinney, tx
  • Region:South west
  • Car Year:1992
  • Car Number:41

LOL at least everyone agrees- OK, here's a little more info, I'm not sure how I missed all these answers until now.

 

 

Knowing that the goal is closer to 200 degree is to me a big tell that they aren't being pushed hard enough to heat up properly.

 

Pressure will tell you that.  well...pressure GROWTH, anyway.   I don't drive SCCA / Hoho's...but,as I understand hot pressures are roughly similar.  I'd be aiming for 36 (+/- 1 psi depending on the track, the corner of the car, setup, and track conditions) psi hot, and 6-9 psi of growth.  So, a cold pressure of 27-30 psi.    If you can't get 6psi of growth, ether the tires are DONE, or grandma needs to pick up the pace.  

 

If your friend went out at 33 psi and came in at 36 psi (from a hot lap)...I get more growth than that in the rain.  


-tch
Build: www.tomhampton.info

video: vimeo.com/tomhampton

Support: X-Factor Racing

 

I didn't lose, I just got outspent!

Beta-Tester - Assisted us with beta testing the website. Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver

#9
bmarshall1

bmarshall1

    Member

  • Members
  • PipPipPip
  • 226 posts
  • Location:United States
  • Region:SW Florida
  • Car Year:1999
  • Car Number:23

Here's the pressures, starting at 33 or 34, I forgot to write down the starting, most likely 33.  I confirmed the tires were 1 year old w/ about 4 - 5 race weekends (including practice, qualifying etc...).   I will check the alignment specs next time we get together.  He also just bought a set of Toyos 

 

Final pressures were:

 

39.5 / 36

 

40.5 / 40

 

I'm certain the RF had a leak, otherwise he was getting 7 lbs increase.



#10
Steve Scheifler

Steve Scheifler

    member

  • Members
  • PipPipPipPipPip
  • 2,568 posts
  • Location:St. Louis
Those pressures are too high. Hoosier may say that more is better but also more skittish, but your national champs are at about 34 +/- 1.5 hot under most circumstances. Lower them a few PSI and they may inspire more confidence. They will also be easier to get up to temp.

Pressure increase depends in part on the amount of moisture in the air (assuming plain air) which is why I mentioned humidity when they were filled. It’s not huge, but enough that I never had mine done on a rainy day and went so far as to let the air out and refill if one seemed to increase more than most. As Tom mentioned, it should be 6-9. We typically see about 6 when starting at around 70 F ambient. That same tire with the same amount of air will measure lower on a cold morning but if run hard will still end up at the same hot pressure, so of course you then see a larger apparent increase.
  • gwash1234 likes this
Bona fide - A bonafide Spec Miata driver

#11
Steve Scheifler

Steve Scheifler

    member

  • Members
  • PipPipPipPipPip
  • 2,568 posts
  • Location:St. Louis
For the record, I’m not saying that tou can’t learn anything from temps, just that nothing definite could be said from your numbers and limited context. Once you know what works best and are confident in your setup they probably aren’t worth a lot of time and effort to monitor routinely, but until then I do find value in them when combined with other information, as I tried to outline above.
Bona fide - A bonafide Spec Miata driver

#12
LarryKing

LarryKing

    Veteran Member

  • Members
  • PipPipPipPipPip
  • 2,602 posts
Has anyone experimented with a tire pressure monitor system?
2017 - SMSE SEDiv ECR Champion
Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver

#13
bmarshall1

bmarshall1

    Member

  • Members
  • PipPipPip
  • 226 posts
  • Location:United States
  • Region:SW Florida
  • Car Year:1999
  • Car Number:23

Those pressures are too high. Hoosier may say that more is better but also more skittish, but your national champs are at about 34 +/- 1.5 hot under most circumstances. Lower them a few PSI and they may inspire more confidence. They will also be easier to get up to temp.

Pressure increase depends in part on the amount of moisture in the air (assuming plain air) which is why I mentioned humidity when they were filled. It’s not huge, but enough that I never had mine done on a rainy day and went so far as to let the air out and refill if one seemed to increase more than most. As Tom mentioned, it should be 6-9. We typically see about 6 when starting at around 70 F ambient. That same tire with the same amount of air will measure lower on a cold morning but if run hard will still end up at the same hot pressure, so of course you then see a larger apparent increase.

Good info - We live in SW Florida, it's always humid when we fill the tires.  Should we be running Toyos at roughly the same hot pressure of 34 +/-

 

I have experienced a morning run starting at 28 lbs, and afternoon run starting at 33 lbs and the hot temps always end up at 39+/-

 

Secondly, at this time the tires temps sounds like next level stuff that we're not able to utilize; but, as a baseline we should want to see @ 200 degrees more or less?



#14
EricJ

EricJ

    Member

  • Members
  • PipPipPip
  • 44 posts
  • Location:Flower Mound, TX
  • Region:Texas
  • Car Year:1999

Has anyone experimented with a tire pressure monitor system?

 

AiM just had a webinar on it. 

 

Matt sells the systems at https://trailbrake.com/



#15
LarryKing

LarryKing

    Veteran Member

  • Members
  • PipPipPipPipPip
  • 2,602 posts

So... are any of the 'top prep' SM teams using them and if so do TPMS provide beneficial data in SM?


2017 - SMSE SEDiv ECR Champion
Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver

#16
Jim Drago

Jim Drago

    East Street Racing / 2 Time National Champion

  • Administrators
  • 6,416 posts
  • Location:Memphis, Tn
  • Region:Mid South
  • Car Year:2005
  • Car Number:2

So... are any of the 'top prep' SM teams using them and if so do TPMS provide beneficial data in SM?

I use a tire gauge in the pits.. does that count :) would be nice though 


East Street Auto Parts
Jim@Eaststreet.com
800 700 9080

NASA Champs Winner - NASA Champs Winner Hoosier Super Tour points Champion - Hoosier Super Tour points Champion ARRC Champion - Won the ARRC Race in a Spec Miata Series Champ - Won a points based series in a Spec Miata BFG Supertour Winner - Majors Winner - Circuit of the Americas Winner - We have a Winnah! - Won their 1st race... Congratulations! June Sprints winner  - June Sprints winner June Sprints winner  - June Sprints winner June Sprints winner  - June Sprints winner June Sprints winner  - June Sprints winner SCCA National Champion - Won SCCA Runoffs at Road America SCCA National Champion - Won SCCA Runoffs at Road America

#17
Tom Sager

Tom Sager

    Veteran Member

  • Members
  • PipPipPipPipPip
  • 1,623 posts
  • Location:Chicago Suburbs
  • Region:Central
  • Car Year:1998
  • Car Number:94

Stopped looking at tire temps years ago.  With the camber we run the inside third of the tire generates heat just driving straight ahead.  Tread temps rise and fall more so than air pressure so that by the time you exit a track off pace, stop in pit lane and stick the probe in all 4 tires in 3 positions each and record the temps, they have changed from the track.   When we did this making modest camber/air pressure changes didn't seem to change the temps at all or only minimally.  No matter what we did the inside and outside third of the tread were the warmest with the middle third a bit cooler.  You can increase air pressure in the tires if you want "prettier" temp numbers but then you're probably above optimal pressures. 

 

I think your more sophisticated formula car teams use infrared temp sensors at each wheel and can read in corner temps and then attempt to set up the car for the most important corners. 

 

I could be dead wrong but I think other setup changes and data are more useful in improving lap times short of a full blown Miliken/Calspan tire test.

 

Edit:  Hopefully this comment ^^^ doesn't motivate anyone to spend the money to do this. 


  • lillyweld likes this
Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver We have a Winnah! - Won their 1st race... Congratulations! Make it Rain - Made Paypal donation of $100+

#18
JRHille

JRHille

    Member

  • Members
  • PipPipPip
  • 429 posts
  • Region:Great Lakes
  • Car Year:1999
  • Car Number:48

I have seen data from temp sensors on a spec miata.  They rise and fall so quickly that you'd HAVE to have these sensors to set camber based on the temp numbers.  Even stopping the car at corner exit to take temperatures wouldn't be very valuable based on what I saw in the data.


  • Tom Sager likes this

1999 Spec Miata
Hilltrux - Roush - V2 Motorsports - ESR
 

BFG Supertour Winner - SCCA National Champion - Won SCCA Runoffs at Road America Majors Winner - Series Champ - Won a points based series in a Spec Miata We have a Winnah! - Won their 1st race... Congratulations! Bona fide - A bonafide Spec Miata driver

#19
bmarshall1

bmarshall1

    Member

  • Members
  • PipPipPip
  • 226 posts
  • Location:United States
  • Region:SW Florida
  • Car Year:1999
  • Car Number:23

Stopped looking at tire temps years ago.  With the camber we run the inside third of the tire generates heat just driving straight ahead.  Tread temps rise and fall more so than air pressure so that by the time you exit a track off pace, stop in pit lane and stick the probe in all 4 tires in 3 positions each and record the temps, they have changed from the track.   When we did this making modest camber/air pressure changes didn't seem to change the temps at all or only minimally.  No matter what we did the inside and outside third of the tread were the warmest with the middle third a bit cooler.  You can increase air pressure in the tires if you want "prettier" temp numbers but then you're probably above optimal pressures. 

 

I think your more sophisticated formula car teams use infrared temp sensors at each wheel and can read in corner temps and then attempt to set up the car for the most important corners. 

 

I could be dead wrong but I think other setup changes and data are more useful in improving lap times short of a full blown Miliken/Calspan tire test.

 

Edit:  Hopefully this comment ^^^ doesn't motivate anyone to spend the money to do this. 

Tom - in follow up, what do you use to gauge set up and adjustment instead of temps? Pressure increase, wear patterns, lap times...



#20
Tom Hampton

Tom Hampton

    Egregious Member

  • SMembers
  • PipPipPipPipPip
  • 2,058 posts
  • Location:Mckinney, tx
  • Region:South west
  • Car Year:1992
  • Car Number:41

Tom - in follow up, what do you use to gauge set up and adjustment instead of temps? Pressure increase, wear patterns, lap times...


Grrr....most post didn't save.

My name is Tom, two (too).

All of the above. Pressure, pressure increase, wear patterns...especially differences between tires. Not that perfectly even pressure growth is NOT the goal, but if something is wildly different, and I had a handling problem that'd be where I'd start. Lap time rules, though. As Saul has said in other threads...."If flipping a brake pad backwards is faster, well....then do that!" So, faster is as faster does.

So, if you've got a corner that's growing 9psi, and everything else is +6....and you've got a handling problem that's related to that corner...then maybe a change is in order (cross or arb) to take some pressure off that tire.

I've taken to recording my tire pressures on my windshield through the day (hot and cold in different colors). I find it really handy to be able to just stare at the car, and see the patterns in pressures over a day's sessions while trying to decide what to do.
  • 915RACEFACTORY likes this

-tch
Build: www.tomhampton.info

video: vimeo.com/tomhampton

Support: X-Factor Racing

 

I didn't lose, I just got outspent!

Beta-Tester - Assisted us with beta testing the website. Donor - Made PayPal donation Bona fide - A bonafide Spec Miata driver




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users