have R7's changed? disturbing grooving
#61
Sarcasm, quite like the ideal gas law escapes you.
Can't wait for this to go fifty plus pages with you presenting all manor of charts and graph about how you're correct and it's not real, even though ten people have told you it is and you're wrong. Can't you see the pattern in your behavior? When will you get the help you so desperately need?
Can't wait for this to go fifty plus pages with you presenting all manor of charts and graph about how you're correct and it's not real, even though ten people have told you it is and you're wrong. Can't you see the pattern in your behavior? When will you get the help you so desperately need?
Just a note for DE guys like you from someone with about 20 years of doing this (99% racing) . NOT MANY at the track, even with track temps of near 140 degrees, have ever seen pressure changes of 14psi its usually about 10 (generally).. do you disagree? and if you understand gas law and see when i come in from a 24psi set pressure and end up at 30psi, that can easily be used to show the temp change of the tire's air. i also added wheel temps and their source of heat driven by brake heat, beyond the tire. this is a factor too)
why are you being so argumentative? did your mommy not give you enough love? i think it is YOU that needs to see someone. I'm just asking a simple question and i think i got the answer anyway. ( he said he had tire air temp readings of over 220degrees, .. then what he saw would be correct) this is not complicated Mike.
#62
I won't get into an argument and several posts were TLDR, but I will verify that I regularly get OVER 10 psi hot pressure jumps. For example, I start at 26 psi then end up at 38 hot (too high for me). And that's just DE, not racing. Paul is a very fast driver so I do not doubt AT ALL that he's seeing 14 psi jumps.
#63
I won't get into an argument and several posts were TLDR, but I will verify that I regularly get OVER 10 psi hot pressure jumps. For example, I start at 26 psi then end up at 38 hot (too high for me). And that's just DE, not racing. Paul is a very fast driver so I do not doubt AT ALL that he's seeing 14 psi jumps.
#65
as a note, as you bring up a good point and is referenced to something i brought up earlier.... My rears and fronts have the near same pressure rise.. my fronts obviously have a LOT more braking heat, but the rears have acceleration loads too, and maybe more tire slip... in the end, they seem to be heated the same.. . One of the main reasons for this is much of the heat is dissipated by the rotor before it hits the hub, even more so with 2 piece rotors. (just a side note on that) by the time i get in the pits, the rotors hit max temps of near 1400degrees, but in the paddock, after a min or so, the rotors are 5-600F. with the rear rotors being in the 350F range... and the rims for both being in the 175 range.. showing a lot of that heat is dissipated by the rotors themselves. I also did a test of how long the pressure takes to go down IN the tire.. 15mins later, they only lost 1psi.....so its easy to measure and this shows what the temp decay is as well.
This reminds me of the " lighter car is easier on brakes with same power" discussion. lots of factors. again, i was just curious. we all know or have heard of gas law. if you are seeing 14psi pressure rise, there has to be the temps to match it... i was asking how that is possible since i haven't seen that on heavier more powerful cars like the Vet and my car that are using the sizes in the discussion from the beginning.
#66
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I haven't read all the other stuff here, but if you started at 75F ambient and ended up at 250F hot air, you would go from about 26 psi to 40 psi. That is certainly possible on a hot sunny day, hot track (I've never seen anywhere near 140F track temps Mark mentioned), heavy car, and certain tire constructions.All in my experience.
Not the same, but remember NASCAR short track cars can set the bead of a tire on fire.
Not the same, but remember NASCAR short track cars can set the bead of a tire on fire.
#67
From the Hoosier site, that Matt posted from, I just noticed this:
Banked Oval / Road Courses
"Hoosier DOT radials are not intended for high banked super speedway or high speed and banked tracks like Watkins Glen International, however on these type of course configurations with the proper settings the tires can be used. In these situations, the loaded side tires should be elevated five (5) psi cold and hot above the normal road course pressure recommendations. Camber settings should be reduced to or below -2.0 degrees."
Banked Oval / Road Courses
"Hoosier DOT radials are not intended for high banked super speedway or high speed and banked tracks like Watkins Glen International, however on these type of course configurations with the proper settings the tires can be used. In these situations, the loaded side tires should be elevated five (5) psi cold and hot above the normal road course pressure recommendations. Camber settings should be reduced to or below -2.0 degrees."
#68
From the Hoosier site, that Matt posted from, I just noticed this:
Banked Oval / Road Courses
"Hoosier DOT radials are not intended for high banked super speedway or high speed and banked tracks like Watkins Glen International, however on these type of course configurations with the proper settings the tires can be used. In these situations, the loaded side tires should be elevated five (5) psi cold and hot above the normal road course pressure recommendations. Camber settings should be reduced to or below -2.0 degrees."
Banked Oval / Road Courses
"Hoosier DOT radials are not intended for high banked super speedway or high speed and banked tracks like Watkins Glen International, however on these type of course configurations with the proper settings the tires can be used. In these situations, the loaded side tires should be elevated five (5) psi cold and hot above the normal road course pressure recommendations. Camber settings should be reduced to or below -2.0 degrees."
I haven't read all the other stuff here, but if you started at 75F ambient and ended up at 250F hot air, you would go from about 26 psi to 40 psi. That is certainly possible on a hot sunny day, hot track (I've never seen anywhere near 140F track temps Mark mentioned), heavy car, and certain tire constructions.All in my experience.
Not the same, but remember NASCAR short track cars can set the bead of a tire on fire.
Not the same, but remember NASCAR short track cars can set the bead of a tire on fire.
the fastest drivers out there in the very fastest cars are seeing around 10psi change. tread temps are in the 180 to 200 degrees regardless of ambient temps. (generally) if we started at 75 degrees, and ended up at over 220F, you would see about 10 psi of change. as a rule of thumb for each 10 degrees , its about 1psi. no one sees this kind of spread you mention 26psi to 40psi that i know of or ever heard of and im constantly polling folks in the paddock. we are all very close like that. like i said, most all the fast cars with the big power and weight in the 2800 to 3000lbs, start out at 22 to 24psi and end up at around 30psi.. i was only asking about the 14psi, because i have never seen or heard of that. I just got off the phone of one of the fastest guys in SCCA club in california... he runs slicks starts out at 19psi and ends up at 29psi. (this guy runs in the 1:27s at laguna and 1:39s at sears with a car weighing 3300lbs and near 1000 hp) The other top guys with 3000lb cars, National champions SCCA, NASA, or the equal to the fastest time in the same cars, run 22 psi to start and end up around 30psi... this is very common. you couldnt run those target pressures, of 30psi, if you had to start at 16psi on a Hoosier... that would be dangerous and tricky to get the tire warm without damaging it... so, i dont know how someone could see 14psi change, but thats why i asked and provided graphs to understand how its possible.
the question is really, how is one to measure tire internal air temps? is there a sensor in the rim that sits in the air and not getting a reading that is influenced by rim temps? curious. we are limited to surface temps with IR guns and penetrating temp gauges.
#69
Originally Posted by mark kibort
Dont be an idiot. learn to read and comprehend Mikey. Look, i was curious as to the reasons and temp readings of why/how someone saw 14psi. I know gas law well, and i dont think you do........because a simple chart like what i posted , even referencing a similar tire size, shouldn't confuse you . the only reason this part of the discussion will go on further , if more idiots join in , not understanding the question i asked. in other words, there is nothing to be "correct" about. i was stating clearly that 14psi would require more temp than most see. he responded with questions about how 30 degrees over road temps is odd. clearly it is HE that doesn't understand some basic laws of thermodynamics, BUT, clearly stated he saw very high temps in his tire, which would follow gas law and be a reason for his high pressure changes.
Just a note for DE guys like you from someone with about 20 years of doing this (99% racing) . NOT MANY at the track, even with track temps of near 140 degrees, have ever seen pressure changes of 14psi its usually about 10 (generally).. do you disagree? and if you understand gas law and see when i come in from a 24psi set pressure and end up at 30psi, that can easily be used to show the temp change of the tire's air. i also added wheel temps and their source of heat driven by brake heat, beyond the tire. this is a factor too)
why are you being so argumentative? did your mommy not give you enough love? i think it is YOU that needs to see someone. I'm just asking a simple question and i think i got the answer anyway. ( he said he had tire air temp readings of over 220degrees, .. then what he saw would be correct) this is not complicated Mike.
Just a note for DE guys like you from someone with about 20 years of doing this (99% racing) . NOT MANY at the track, even with track temps of near 140 degrees, have ever seen pressure changes of 14psi its usually about 10 (generally).. do you disagree? and if you understand gas law and see when i come in from a 24psi set pressure and end up at 30psi, that can easily be used to show the temp change of the tire's air. i also added wheel temps and their source of heat driven by brake heat, beyond the tire. this is a factor too)
why are you being so argumentative? did your mommy not give you enough love? i think it is YOU that needs to see someone. I'm just asking a simple question and i think i got the answer anyway. ( he said he had tire air temp readings of over 220degrees, .. then what he saw would be correct) this is not complicated Mike.
#70
Actually i do. I've seen you drive.... You think you are a racer? you get confused by a simple Gas Law chart, so i suspect you dont have much engineering education.. you being a scientist, (My wife was a scientist/ genetic engineer and didnt know much about tire pressures either, so dont feel bad ) You would think that this would be fairly straight forward for you . But one thing for sure, you dont have manners! maybe you should consider a finishing school.
Last edited by mark kibort; 09-19-2018 at 08:04 PM.
#74
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I get my measurements from TPMS. Most, if not all, motorsport grade TPMS transmit temp with the pressure. That is one of the great things about using them. As to the influence from rim temp, that depends on the sensor, type, insulation, car, etc. Sensors like the high end McLaren and BF1 system have pressure, temp, and internal tire IR sensors. The internal IR is pretty cool, but hard to make use of unless you have a tire deal and GREAT tire engineering support from a manufacturer. That level of help is only at the very highest levels where tire choice is wide open.
#75
I get my measurements from TPMS. Most, if not all, motorsport grade TPMS transmit temp with the pressure. That is one of the great things about using them. As to the influence from rim temp, that depends on the sensor, type, insulation, car, etc. Sensors like the high end McLaren and BF1 system have pressure, temp, and internal tire IR sensors. The internal IR is pretty cool, but hard to make use of unless you have a tire deal and GREAT tire engineering support from a manufacturer. That level of help is only at the very highest levels where tire choice is wide open.
I forgot to mention a clarification to your comment about never seeing a "140F " tracktemp.... I was talking about asphalt temps. (pointing the IR gun on the asphalt). usually when its about 100 to 110 degrees, you can see this kind of temps on the track. still , tire temps were (surface tread) were under 180-200F in the hot pit area.
anyway, here is a tire temp sensor, but its external. ive never heard of internal air temp sensor
Last edited by mark kibort; 09-19-2018 at 09:56 PM.