Tire pressure for the Cup2 tire at the track??
06-09-2019, 03:57 PM
#31
Rennlist Member
06-09-2019, 04:13 PM
#33
Rennlist Member
Most here are pros and know their cars and as you can see are starting at 28 cold front and 31-32 rear. Then bleed off when they get warm. Different pavement temps determine how much psi you want. Hotter it gets greasy feeling. On the street too! I've noticed that once my PS2's have a few miles on them they will hold more psi then when new. I actually don't like the grip of these tires when they are brand new.
06-09-2019, 10:29 PM
#34
There is an entire thread on this, and the same questions raise the same issues. Tire temp and tire pressure are not equal to each other. IF you are getting greasy, non shedding tires, the temp is too hot! If you really want to get this simplified, get a set of chicken hawk tire warmers. put them on 175 degrees. Let the tires get all the way to temp prior to going out. set the corrected HOT tire recommendations and you should be fine. Continually lowering the pressure, increases heat, and bakes the tire. cold temps are inaccurate and have no bearing on the tire temp until the tire is totally at correct performance temp.
Example. cold tire, no laps, 28lbs, 75 degrees out, you go out for 20 min, you check the tire temp and pressure prior to the laps, then check asap when you get off track, if you are over the tire recommended hot temp, your pressure will be very high, ADD AIR, YES ADD AIR, if you are below the recommended temp of the tire, your pressure will be low, LOWER pressure a few lbs.
The tire warmers create the optimum tire temp, not pressure, temp, race temp! Set the temp and forget them. You will have minor adjustments, and usually as you get faster, you end up adding AIR, as you add air you keep the tire temp lower. Continually taking air out of the tire, increases temp and destroys the tire. It bakes it to death, then they are a greasy mess, it stops shedding and the compound of the tire is ruined, and you lose grip.
Example. cold tire, no laps, 28lbs, 75 degrees out, you go out for 20 min, you check the tire temp and pressure prior to the laps, then check asap when you get off track, if you are over the tire recommended hot temp, your pressure will be very high, ADD AIR, YES ADD AIR, if you are below the recommended temp of the tire, your pressure will be low, LOWER pressure a few lbs.
The tire warmers create the optimum tire temp, not pressure, temp, race temp! Set the temp and forget them. You will have minor adjustments, and usually as you get faster, you end up adding AIR, as you add air you keep the tire temp lower. Continually taking air out of the tire, increases temp and destroys the tire. It bakes it to death, then they are a greasy mess, it stops shedding and the compound of the tire is ruined, and you lose grip.
06-10-2019, 12:39 AM
#35
Nordschleife Master
Originally Posted by Dougr743
There is an entire thread on this, and the same questions raise the same issues. Tire temp and tire pressure are not equal to each other. IF you are getting greasy, non shedding tires, the temp is too hot! If you really want to get this simplified, get a set of chicken hawk tire warmers. put them on 175 degrees. Let the tires get all the way to temp prior to going out. set the corrected HOT tire recommendations and you should be fine. Continually lowering the pressure, increases heat, and bakes the tire. cold temps are inaccurate and have no bearing on the tire temp until the tire is totally at correct performance temp.
Example. cold tire, no laps, 28lbs, 75 degrees out, you go out for 20 min, you check the tire temp and pressure prior to the laps, then check asap when you get off track, if you are over the tire recommended hot temp, your pressure will be very high, ADD AIR, YES ADD AIR, if you are below the recommended temp of the tire, your pressure will be low, LOWER pressure a few lbs.
The tire warmers create the optimum tire temp, not pressure, temp, race temp! Set the temp and forget them. You will have minor adjustments, and usually as you get faster, you end up adding AIR, as you add air you keep the tire temp lower. Continually taking air out of the tire, increases temp and destroys the tire. It bakes it to death, then they are a greasy mess, it stops shedding and the compound of the tire is ruined, and you lose grip.
Example. cold tire, no laps, 28lbs, 75 degrees out, you go out for 20 min, you check the tire temp and pressure prior to the laps, then check asap when you get off track, if you are over the tire recommended hot temp, your pressure will be very high, ADD AIR, YES ADD AIR, if you are below the recommended temp of the tire, your pressure will be low, LOWER pressure a few lbs.
The tire warmers create the optimum tire temp, not pressure, temp, race temp! Set the temp and forget them. You will have minor adjustments, and usually as you get faster, you end up adding AIR, as you add air you keep the tire temp lower. Continually taking air out of the tire, increases temp and destroys the tire. It bakes it to death, then they are a greasy mess, it stops shedding and the compound of the tire is ruined, and you lose grip.
06-10-2019, 06:39 AM
#36
The strange thing is, if you look at what Michelin recommends, you can see that they have changed over the years. I have found three different documents. The first having the lowest pressures and the last the highest. I would guess that they have gone more and more conservative due to issues over the years?
First document I found (2015):
Cold tires
• Inflate the MICHELIN Pilot Sport Cup2 with a pressure between 1.7 bar (24 psi) and 1.8 bar (26 psi) front & rear
• Never allow the pressure to be below 1.5 bar (22 psi)
Hot tires
• The optimal operating pressure of the MICHELIN Pilot Sport Cup2 must be between 2.3 bar (33 psi) and 2.5 bar (36 psi) Front & Rear
• Never allow the tyres to run below 2,0 bar (29 psi) HOT
Last document (2016):
COLD TYRES
• Don’t ever use inflation pressure below 1.9 bar (28 psi) cold
• To optimize the track longevity of MICHELIN PILOT SPORT CUP 2, MICHELIN strongly recommends to use a minimum inflation pressure between 2.0 (29 psi) and 2.4 bar (35 psi)
HOT TYRES
• The best operating pressure of MICHELIN PILOT SPORT CUP 2 is between 2.3 bar (33 psi) and 2.7 bar (39 psi) hot, according vehicle model and track where used
• However, some vehicle models will need a higher inflating pressure than 2.7 bar (39 psi Hot)
If you look at the minimum recommended you can see that they went from 22 psi to 28 psi for cold tires. Quite a substantial difference.
First document I found (2015):
Cold tires
• Inflate the MICHELIN Pilot Sport Cup2 with a pressure between 1.7 bar (24 psi) and 1.8 bar (26 psi) front & rear
• Never allow the pressure to be below 1.5 bar (22 psi)
Hot tires
• The optimal operating pressure of the MICHELIN Pilot Sport Cup2 must be between 2.3 bar (33 psi) and 2.5 bar (36 psi) Front & Rear
• Never allow the tyres to run below 2,0 bar (29 psi) HOT
Last document (2016):
COLD TYRES
• Don’t ever use inflation pressure below 1.9 bar (28 psi) cold
• To optimize the track longevity of MICHELIN PILOT SPORT CUP 2, MICHELIN strongly recommends to use a minimum inflation pressure between 2.0 (29 psi) and 2.4 bar (35 psi)
HOT TYRES
• The best operating pressure of MICHELIN PILOT SPORT CUP 2 is between 2.3 bar (33 psi) and 2.7 bar (39 psi) hot, according vehicle model and track where used
• However, some vehicle models will need a higher inflating pressure than 2.7 bar (39 psi Hot)
If you look at the minimum recommended you can see that they went from 22 psi to 28 psi for cold tires. Quite a substantial difference.
06-10-2019, 08:49 AM
#37
Addict
Rennlist Member
Rennlist Member
Originally Posted by Dougr743
There is an entire thread on this, and the same questions raise the same issues.
06-10-2019, 08:59 AM
#38
Race Director
The strange thing is, if you look at what Michelin recommends, you can see that they have changed over the years. I have found three different documents. The first having the lowest pressures and the last the highest. I would guess that they have gone more and more conservative due to issues over the years?
.
.
That is because the MPSC2 tires have changed in construction....hence Michelin has changed recommendations.
06-10-2019, 12:11 PM
#39
Drifting
This past track weekend I found I liked 35psi, front and 38psi, rear (hot). Cold, I had tires at 28psi front and 32psi rear. After warm-up session, I reduced pressures to 35/38 and they pretty much stayed stable the rest of the day. It was about 90-100 degrees out. These tires currently have about 7K miles on them.
06-10-2019, 02:10 PM
#40
SO tires and recommendation. all are affected by car, driver, weight, tarmac surface etc etc. the reason I keep beating the drum on warmers, is the up front cost of 2500 is pennies if you keep delaminating tires. Put them on, turn them up. Wait until they register (most turn on and off keeping them stable) go out and rip it, come in, put them on and you never heat cycle the tire, they stay in their happy place. The tires will shed like mad, not greasy, you will benefit, save tires, run faster laps, get better feedback from the car, and have a simplified starting place for the next time you go to the track. IF you are having success, without warmers, it really luck! Its a combination of guessing what tire pressure to start with, and your averages, ex. laps, times, conditions of track etc. As the day go's on, more rubber is on the track, better traction and, usually, faster laps. hence, most are adding air.
If I came off the track higher than the tire temp going out, I am ADDING AIR! I want my tire to be with in a few degrees coming off the track, back on the warmers. IF they are really high, ADD MORE AIR!. If they are really low, take some out. If you go out hot at 35 and come in at 32, take 2 or 3lbs out, you will come back in at 35. If you are not getting enough heat into the tire, it will be slippery and tear, no Shed, Tear. Tearing looks like ripples of rubber pushed over. Like a paper cut on your finger. They are cold tears. The car will feel like it steps out, then usually catches. Contact temp is not internal temp. So you could go out and spin tires all day long, its not core tire temp. you need core tire temp to really manage this.
If you get a chance to borrow someones tire warmers ( i don't know if you can rent them ) Don't check your cold temp at all, put them on, set your hot temp. I bet 99% of the people killing tires are starting way too low. Never really giving the tire to get up to temp properly. Hope this helps Watch the F1 guys, they wrap the entire wheel before they even get the car into the paddock bay. Its literally one mans Job, just to wrap the freaking tire! Most important game to play.
I cringe when I think of all the Caster/camber threads, only because i think a lot of the management issues are tire temps, not set up. I think there are benefits to proper set up, but its impossible to set up any car or bike etc etc without tire temp control. how do you know what the car is doing when the car is responding to the tire, then all the NANNYS and electronics to help manage the mismanagement of the rubber?
If I came off the track higher than the tire temp going out, I am ADDING AIR! I want my tire to be with in a few degrees coming off the track, back on the warmers. IF they are really high, ADD MORE AIR!. If they are really low, take some out. If you go out hot at 35 and come in at 32, take 2 or 3lbs out, you will come back in at 35. If you are not getting enough heat into the tire, it will be slippery and tear, no Shed, Tear. Tearing looks like ripples of rubber pushed over. Like a paper cut on your finger. They are cold tears. The car will feel like it steps out, then usually catches. Contact temp is not internal temp. So you could go out and spin tires all day long, its not core tire temp. you need core tire temp to really manage this.
If you get a chance to borrow someones tire warmers ( i don't know if you can rent them ) Don't check your cold temp at all, put them on, set your hot temp. I bet 99% of the people killing tires are starting way too low. Never really giving the tire to get up to temp properly. Hope this helps Watch the F1 guys, they wrap the entire wheel before they even get the car into the paddock bay. Its literally one mans Job, just to wrap the freaking tire! Most important game to play.
I cringe when I think of all the Caster/camber threads, only because i think a lot of the management issues are tire temps, not set up. I think there are benefits to proper set up, but its impossible to set up any car or bike etc etc without tire temp control. how do you know what the car is doing when the car is responding to the tire, then all the NANNYS and electronics to help manage the mismanagement of the rubber?
06-10-2019, 02:18 PM
#41
Drifting
I have find that with the N2 version of Cup 2s I cant start off at quite as low pressures like I was running on the N0 and N1 versions; on my 991.1 RS would start out 24/25 psi and let them build up into low 32-34 range for ideal grip. However with the N2 if I go that low to start then then car is uncontrollable. Also, I have found N2 version likes mid 30s better for ideal grip with my 991.2 RS. Anyone else notice similar changes? I am also getting better wear with the N2s which has been a nice change!
06-10-2019, 02:46 PM
#42
Addict
Rennlist Member
Rennlist Member
SO tires and recommendation. all are affected by car, driver, weight, tarmac surface etc etc. the reason I keep beating the drum on warmers, is the up front cost of 2500 is pennies if you keep delaminating tires. Put them on, turn them up. Wait until they register (most turn on and off keeping them stable) go out and rip it, come in, put them on and you never heat cycle the tire, they stay in their happy place. The tires will shed like mad, not greasy, you will benefit, save tires, run faster laps, get better feedback from the car, and have a simplified starting place for the next time you go to the track. IF you are having success, without warmers, it really luck! Its a combination of guessing what tire pressure to start with, and your averages, ex. laps, times, conditions of track etc. As the day go's on, more rubber is on the track, better traction and, usually, faster laps. hence, most are adding air.
If I came off the track higher than the tire temp going out, I am ADDING AIR! I want my tire to be with in a few degrees coming off the track, back on the warmers. IF they are really high, ADD MORE AIR!. If they are really low, take some out. If you go out hot at 35 and come in at 32, take 2 or 3lbs out, you will come back in at 35. If you are not getting enough heat into the tire, it will be slippery and tear, no Shed, Tear. Tearing looks like ripples of rubber pushed over. Like a paper cut on your finger. They are cold tears. The car will feel like it steps out, then usually catches. Contact temp is not internal temp. So you could go out and spin tires all day long, its not core tire temp. you need core tire temp to really manage this.
If you get a chance to borrow someones tire warmers ( i don't know if you can rent them ) Don't check your cold temp at all, put them on, set your hot temp. I bet 99% of the people killing tires are starting way too low. Never really giving the tire to get up to temp properly. Hope this helps Watch the F1 guys, they wrap the entire wheel before they even get the car into the paddock bay. Its literally one mans Job, just to wrap the freaking tire! Most important game to play.
I cringe when I think of all the Caster/camber threads, only because i think a lot of the management issues are tire temps, not set up. I think there are benefits to proper set up, but its impossible to set up any car or bike etc etc without tire temp control. how do you know what the car is doing when the car is responding to the tire, then all the NANNYS and electronics to help manage the mismanagement of the rubber?
If I came off the track higher than the tire temp going out, I am ADDING AIR! I want my tire to be with in a few degrees coming off the track, back on the warmers. IF they are really high, ADD MORE AIR!. If they are really low, take some out. If you go out hot at 35 and come in at 32, take 2 or 3lbs out, you will come back in at 35. If you are not getting enough heat into the tire, it will be slippery and tear, no Shed, Tear. Tearing looks like ripples of rubber pushed over. Like a paper cut on your finger. They are cold tears. The car will feel like it steps out, then usually catches. Contact temp is not internal temp. So you could go out and spin tires all day long, its not core tire temp. you need core tire temp to really manage this.
If you get a chance to borrow someones tire warmers ( i don't know if you can rent them ) Don't check your cold temp at all, put them on, set your hot temp. I bet 99% of the people killing tires are starting way too low. Never really giving the tire to get up to temp properly. Hope this helps Watch the F1 guys, they wrap the entire wheel before they even get the car into the paddock bay. Its literally one mans Job, just to wrap the freaking tire! Most important game to play.
I cringe when I think of all the Caster/camber threads, only because i think a lot of the management issues are tire temps, not set up. I think there are benefits to proper set up, but its impossible to set up any car or bike etc etc without tire temp control. how do you know what the car is doing when the car is responding to the tire, then all the NANNYS and electronics to help manage the mismanagement of the rubber?
1. The need for 120V power to run the tire warmers (needs two separate 15 Amp circuits)
2. The need (strong preference, at least) to have the car in the air when applying the warmers, otherwise you don't heat the whole tire and not great for the warmers to have the weight of the car on them (and clearance is much better when the suspension is sagging when on stands).
I drive to the track and I don't have anywhere to put a generator to run the warmers (wouldn't be easy for me to arrange for 2 15A circuits at the track). I don't travel to the track with jacks and jack stands.
06-10-2019, 03:05 PM
#43
I found this idea of tire warmers interesting and compelling, however, there are two issues that I am struggling with:
1. The need for 120V power to run the tire warmers (needs two separate 15 Amp circuits)
2. The need (strong preference, at least) to have the car in the air when applying the warmers, otherwise you don't heat the whole tire and not great for the warmers to have the weight of the car on them (and clearance is much better when the suspension is sagging when on stands).
I drive to the track and I don't have anywhere to put a generator to run the warmers (wouldn't be easy for me to arrange for 2 15A circuits at the track). I don't travel to the track with jacks and jack stands.
1. The need for 120V power to run the tire warmers (needs two separate 15 Amp circuits)
2. The need (strong preference, at least) to have the car in the air when applying the warmers, otherwise you don't heat the whole tire and not great for the warmers to have the weight of the car on them (and clearance is much better when the suspension is sagging when on stands).
I drive to the track and I don't have anywhere to put a generator to run the warmers (wouldn't be easy for me to arrange for 2 15A circuits at the track). I don't travel to the track with jacks and jack stands.
So this is my suggestion
1. Set the tires at normal road pressure. Run your first 3 to 4 laps a moderate speeds, then gradually bring your speed up for your first session, check pressure and tire temp asap. Then make adjustments. I would bet that your ambient temp to "HOT" temp would be much closer to proper race temp without dropping a lot of pressure to start. You really want to get the correct temp, then adjust. I would bet the HOT temp is really way over the proper temp, when you go out on a 24lb tire. Its cooking that tire. Lower pressure heats the tire quickly, the heat continues to build, the heat is causing the increase in pressure. Higher pressure, slower heat exchange, but tire will react properly if you keep the heat within the operating ranges.
i know this is winded and I am rambling over this, but Its really the #1 problem if you plan on getting multiple days out of tires, and consistent tire performance. Also you cannot put warmers on tires sitting on the ground.
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ariotofcolor (11-25-2020)
06-10-2019, 03:06 PM
#44
Addict
Rennlist Member
Rennlist Member
Thanks!
06-10-2019, 03:19 PM
#45
I plan on getting a new trailer next year, and adding a lift inside the trailer. so I can come off the track, pull onto the trailer, hit the button, lift the car, wrap the tires, Or, make a side entry, 4 post jack, that you can lift the entire car enough to wrap the tires. If i dump 5k into a system that works, It will save me that 5k in the first year. I haven't had any time to put a plan together, I am finishing other Family projects and plan on a solution this winter, so I can get rocking next year. I promised the misses I would finish other things and ignore getting on the track this year. I am all in with coming up with some cool, simple solutions.
maybe thats a new thread we can start!
maybe thats a new thread we can start!