Real Road 2.0 and track temperatures on tyres problem (July RC)

Discussion in 'General Discussion' started by ilgrillo, Jul 16, 2022.

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  1. ilgrillo

    ilgrillo Registered

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    I suspect that for real road 2.0 they only simulated the tire surface based on the asphalt temperature and not based on the tire shell temperature which in turn is affected by the asphalt temperature.

    Otherwise, there is no explanation why tires temperatures and pressure do not change with 50°C difference between stints.
     
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  2. doddynco

    doddynco Registered

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    Because your considerate driving is compensating and keeping the tyres at a reasonable temperature, by not trying to overdrive them.

    The cooler, stiffer tyres build heat easily, the hotter tyres disintegrate and loose temperature in the form of lost rubber, they also require more and more energy to heat as they increase in temperature. therefore you reach a kind of equilibrium.

    Also you seem to be ignoring actual differences in your data - the temp is lower with a cooler track, the pressure is lower with cooler tyres surface temps. You're expecting massive differences but unless you drive with no brain you will drive the car differently for the varying grip. There's two seconds between your oven hot and normal race conditions - which is huge. You're therefore generating less friction energy in the oven hot conditions during cornering.
     
  3. mantasisg

    mantasisg Registered

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    Why do you decide so easily that there is no explanation ? I wrote bunch of reasonable stuff. Maybe too difficult to understand. But there could be more. For example, you could assume that rF2 spawns a car with tire that is already the temperature of ambient, which I don't if it is true, but would check now, it also makes difference for test result. There are lots of explanations, and the truth isn't necessarily black or white.

    I don't say you are wrong, I even haven't tested anything myself as well. But if I would, I'd drive for few laps several seconds off pace on purpose, to eliminate any abuse of tires. I'd check garage temps, I'd also check for core temps in garage menu.

    Try my mazda miata mx5 it is on steamworkshop downrated to three stars down into oblivion, I wonder how it would react lol
     
  4. doddynco

    doddynco Registered

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    If you want to prove something, you must minimise the amount of variables. How about keeping your lap times the same with varying track temperature? Then we can actually see something useful.

    1m 6.5 seconds * 8 = 8m52s

    So do 8 laps at 5 degreeC ambient in 8m52s

    Then do 8 laps at 45 degree ambient in 8m52s.

    Stay at a consistent 1m6.5 seconds per lap, or as close as possible..
    Record it using OBS and post it to youtube!
     
  5. ilgrillo

    ilgrillo Registered

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    Of course, for the two scenarios, I have also tried changing the tire pressures (especially the right tire pressures to equalize the left tire temperatures), but nothing changes, the temperatures remain the same whether I raise or lower the pressures.
    They always remain about 77°C on the left and about 65°C on the right.
     
  6. ilgrillo

    ilgrillo Registered

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    doddynco, again: there are 50°C difference between the two scenarios.

    It's impossible that I come out of the pits with the same pressures and not have consistent changes in tyres temperatures for laps that vary by at most one second between the two scenarios.

    I'm going to try the 1m 6 seconds pace, but if you try it you can tell right away that something is not working properly.

    The difference in grip, on the other hand, can be felt, and that one is nice.
     
  7. davehenrie

    davehenrie Registered

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    Would a ten mile straight be useful for testing? Seems that would eliminate the variances in left/right movements.(don't get any ideas, I DON"T have one)
     
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  8. mantasisg

    mantasisg Registered

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    TL;DR It could be that rF2 cars tires parameters stores too little heat at surface, or/and has too rapid conductivity. Thus fluctuates quickly to normal levels after finishing turns, and not staying long enough to significantly rise core temperatures, which would in chain reaction raise tire pressures more than it does now. Good thing is that it is adjustable in cars physics files. If it is needed to be adjusted, first of all.

    Lots of interesting tests to be done about this new feature. Would be interesting to see if it would be possible to overheat tire just on straight by making car very heavy, or by adding tons of downforce. But usually tires would mostly cool down by driving through straights by transfering heat into tarmac. Obviously, it should definitely do less so if tarmac is 50C cooler, or hotter.

    As I mentioned before as in pretty much every physics topic, not only sim physics should be a suspect, cars physics files are also always among usual suspects. So I mentioned ThermalDepthAtSurface parameter at my previous post, which nobody ever gonna read. This parameter has strong effects on tire temperatures fluctuation. Most cars in rF2 has very quick fluctuation due to thin depth setting.

    I don't know if it is correct, but to me intuitively it isn't. This parameter is also a player in this case, if surface thermal depth setting was thicker smply more heat would be stored.

    For example, I did set it a bit thicker for 1967 endurance cars, and I think most of my other cars. With original values such as found in ISI tires, they would always in any case get cool through Hunaudieres straight, even with GT40 MK4 going at 340km/h+. I don't remember exact numbers but I remember tire app color would get blue, and temps would drop under 30 IIRIC. I added bit thicker thermal depth parameter, and then they didn't get cooler than ~40degs, I don't remember exact numbers. Then you arrive to Mulsanne corner not with completely cooled off tires, and have little bit better braking at initial distance, assuming brakes aren't totally cold after the straight which also well simulatable in rF2.

    Slight play with thermal depth and conductivity parameters and you'd achieve anything you desire, but would it be realistic ? We need good references and data to know. It is reasonable to expect huge differences about everything in extreme range of 50C ambient, and even more of road temps. So far I have seen that there surely are noticeable instantaneous differences that gives different laptimes and wear, but such long lasting effects like adding up more pressure and building up more heat than it actually does could be definitely tied to low amount of thermal storage in a tire surface plus quick thermal conductivity. Thats my thought before testing or researching anything.
     
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  9. Raintyre

    Raintyre Registered

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    Oh, my...
    Why some of you make big efforts to deny the evidence that somebody is showing? It is a very important flaw and should be implemented correctly, not hidden under a carpet. Do you really want a complete simulation or a fantasy car game?
     
  10. mantasisg

    mantasisg Registered

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    Why not... should lead towards even better evidence and arguments. If something is wrong.

    Worst case, as some of us experienced, is when no one even cares.
     
    Last edited: Jul 17, 2022
  11. ebeninca

    ebeninca Registered

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    He did tests with different temperatures and it seems to be responding as expected.



    upload_2022-7-17_19-50-7.png

    upload_2022-7-17_19-51-0.png
     
    Last edited: Jul 17, 2022
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  12. ilgrillo

    ilgrillo Registered

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    Yes, I had seen that before.
    He did even more extreme tests: 0°C and 60°C.
    Higher tire temperatures of only 15°C without changes in pressures seems to me to be unacceptable values.

    Yesterday I tried again tests with more normal temperatures: 10°C and 30°C and with Heavy grip preset. Again with the CR.8 GTE with the new tire physics.
    I increased the pressure of the FR by 5 points and the RR by 3 points to have uniform pressures in both scenarios (since pressures at the moment are not related to asphalt temperature) and in fact after about 5 laps the pressures were aligned.
    I ran for 10 laps.
    Temperatures were similar in the middle of the Hangar Straight.
     
  13. mantasisg

    mantasisg Registered

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    Perhaps not the best comparison, but still something to start with instead of theorizing.

    Two 2013 F1 Thermal imaging onboards with hot and cool tracks. India Q2 ambient was about 30C and track was close to 40C. In Japan it was low 20C, I suppose track must have been close to 30C. I assume color coding for thermal imaging was same. Vettel lap seems not be quite on the limit. Also India track appears to have a lot faster and longer more intense turns, which definitely puts more stress on tires.

    https://en.wikipedia.org/wiki/2013_...ext=The session was held in,a lap of 1:24.119.
    https://f1madness.co.za/weather-forecast-2013-formula-1-japanese-grand-prix/




    Interestingly tire parts that stays on the tarmac doesn't cool down completely, even though it seems it would keep transferring heat to tarmac. Because deformations, camber thrust and rolling friction ? In Suzuka onboard at cooler track tires obviously heats up less, and cools down more and quicker, but it also is much less on the limit than in India onboard, while also India track is also obviously stressing tire more. Still, notice that after finishing the lap Alonso tires didn't cool down completely by the end of the straight, also notice how he purposely started the lap with cooled down tires, which remained stable heat through the straight on the inner edges.
     
  14. mantasisg

    mantasisg Registered

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    Discovering more interesting videos. Bit more suitable since this is not open wheeler (so is cooled less by wind) and also includes actual temperatures.



    Notice how in this case temps drops down exponentially fast once they are over 60C, and once under 60C the surface starts cooling down slowly. Obviously nothing surprising about it, but it is interesting to see how narrow the gap is between wild temp fluctuation and where it stops cooling rapidly.
     
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  15. ebeninca

    ebeninca Registered

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    So, I remind of testing this system when iRacing launch it some years ago... I don't have the data, but I found a video from the Simpit (Shawn Cole) doing it...



    upload_2022-7-18_10-41-25.png

    He's considering the tire with most load/wear during the tests (Right Front). I converted the values from Fahrenheit to Celsius:

    HOT AMBIENT 32,2º = TIRES 71,6º
    COLD AMBIENT 18,3º = TIRES 67,2º


    So, there you have it, for a 14º change in ambient temperature, the tires changed only 4º.

    If someone can take the same data from Assetto Corsa Competizione, it can be useful too.
     
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  16. Comante

    Comante Registered

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    Heat transfer rate is linked to temperature delta : more something is hot compared to the surrounding environment, faster it will try to cool down. I've read the thread only quickly, but other than remember everyone that this is the first iteration of a new feature (despite being one of those things that should have been in place since day 1) it is probable that a lot of thing should cascade updated to make all the wirings work properly.
    2) I think I've read that actually the feature work only within a temperature window, so trying to check if it work at extreme temperatures may not be the best course of action.
     
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  17. mantasisg

    mantasisg Registered

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    Yes, option for 40+ degrees of Celsius is already wild, let alone having 60. But it means simulation should still be capable to deal with it.

    Yes, something like that should be expected. Although there probably is a difference, those are likely core temperatures. So it would be interesting to check rF2 core temperatures too, as they are a lot more stable. As seen surface temps fluctuate rather quickly, especially if they have physics parameters that has set thermal depth very thin. Couple seconds of rolling in straight, and they eventually become even more similar despite ambient having extreme difference. But it is likely that they should be more different than they are as OP is trying to tell, although not really participating in discussing.
     
  18. ebeninca

    ebeninca Registered

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    I believe it's possible with DAMPlugin/Motec.

    upload_2022-7-18_12-33-14.png

    In my understanding the "Tyre Rubber Temp" is relative to a more internal band (core), and "Tyre Temp" to a more external part (same shown in the rFactor2 MFD HUD)

    If someone have the time to test and analyze the data.
     
    Last edited: Jul 18, 2022
  19. mantasisg

    mantasisg Registered

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    Yes, using this plugin would be definitely the choice. But core temps also should be displayed in garage menu.
     
  20. ebeninca

    ebeninca Registered

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    Unfortunately the temperatures that you see in garage are the same from MFD HUD (external band / "Tyre Temp"), so you'll need Motec for core temperatures.

    upload_2022-7-18_17-8-31.png


    upload_2022-7-18_17-9-21.png
     
    Last edited: Jul 18, 2022

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