• Blurring the line between real and virtual motorsports
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Tires pressure GT3

Discussion in 'Assetto Corsa' started by BhZ, May 27, 2016.

  1. BhZ

    Premium Member

    What pressure do you use in GT3 usually? Since Soft overheat easily, do you increase tire pressure? And what about mediums? Mediums don't overheat so do you usually decrease the pressure to have more grip?
  2. ideal pressure for tyres is 33psi when working. And dont increase the pressure if your tires overheat :)
  3. Glaurung

    Staff Member Premium Member

    Tyre compounds are dictated by track temperature and track's characteristics.
    If tyres overheat, apart a slight reduction softening springs, there's no other choice to go towards harder compounds.
    • Like Like x 2
  4. I usually set them at 24 psi in setup. I don't know what is their pressure after some laps. But with this value I am the fastest and car feels stable and great. I usually am in top 10 in rsr live time with gt3 cars, so I guess this speaks something. When I download some setups and psi is set to vaulues like 33, the cars are pretty much undrivable. So basicly... try out some vaules and find what works best for you, becasue it is different for everyone.
  5. you set them at 24 cold... 33 hot is optimal pressure, which you reach if you set your cold pressure at 25/24/23 psi, depending on the track (brands for example requires lower pressure, because of series of right handers)
    • Like Like x 1
  6. Yes I do. But some people do set their tires at 33-35 psi cold ! Undrivable no matter if it is the first lap or 10th.
  7. because they have the wrong idea.
  8. Alex Townsend

    Alex Townsend
    Premium Member

    Must admit I've not changed mine ever... what is the default?
  9. Qazdar Karim

    Qazdar Karim
    Premium Member

    This is one of AC's physics flawed aspects: the whole idea of "ideal pressure" is wrong, there isn't such thing in real life, at least not in the way described it in the physics files, ofcourse there is an ideal pressure for a track that is some kind of compromise between grip and low and high speed.
  10. Would you mind expanding on this? At first, you say that the idea of an ideal pressure is wrong. But then you say there IS an ideal pressure. I'm a bit confused. I'll admit that I am completely naive about this subject and I've tried different recommended air pressure values from conversations I've read on forums. I could tell the difference most of the time...
  11. Qazdar Karim

    Qazdar Karim
    Premium Member

    Yes, it's a bit confusing but i will try to make it clearer:

    the IDEAL_PRESSURE on the physics files is the one that doesn't exist in real life, because it tells you that no matter how the track is as long as you are around that pressure you are good, but it's wrong, because it depends on the tyre load, in high speed corners for example ,where the tyre load is big, you need a high pressure on your tyre (more stiffness), in slow corners (low loads), you 'd better have a low pressure for grip. Please note that i'm using high/low speed corners analogy just to help you visulaize the thing ... technically it's related to tyre loads, low pressure is good for low loads situations and high pressure is good for high loads situations.

    This said, for each track/car combination, there is an optimal static pressure that is some sort of compromise between high/low loads situations, in Monaco for example, i would most likely go for a low tyre pressure since there are a lot of slow corners/traction zones. On Silverstone, i would like a higher pressure because of the high speed sections.

    I hope @kunos will take a look into this.
    Last edited: Jun 6, 2016
    • Like Like x 2
  12. Thank you for explaining what you meant, more clearly, for me...
  13. I mean...yes you change the hot pressure per track, but at the same time, not really....there is most definitely an optimum pressure, and at the end of the day, changing a psi up or down isn't really going to make the tire compress all that much more (unless it's a very spongy tire with huge stiffness change per psi). If you inquire any tire manufacturer (race or road) about the optimum pressure that their tires perform at, they will give you a number (or a ~2 psi range). Tires are designed to perform at a certain pressure, if you're above or below that, you will run into issues (whether it's grip or structural integrity). For example, for Dunlop's LMP2 tires, they specifically state not to run the tires below 1.9 bar because the likelihood of them failing skyrockets. Their optimum pressure is 2.0 bar...not much room to play around with.
  14. Qazdar Karim

    Qazdar Karim
    Premium Member

    That is related to the tyre structure and the fact that it could fail at very low/high pressures, but if the only parameter is tyre load, more stiffness is good at high loads and less at low loads.
  15. Yes I agree with that part, but since the tire stiffness really doesn't change all that much with a 1.5 psi difference (the max allowable by the Dunlop P2 tires), there's no point in running outside of the optimum (you end up with a ~4% difference in stiffness, which isn't enough to make a proper difference).
  16. Qazdar Karim

    Qazdar Karim
    Premium Member

    I think that it would make a difference, especially on the "dynamic" hot pressure,10-12 N/mm/PSI is not negligible.

    Anyway, AC needs a proper grip/pressure/load implementation; the current IDEAL_PRESSURE doesn't make sense, probably road cars won't benefit from this change, but it will make a difference for racing cars.
  17. ouvert

    Premium Member

    relation between tyre pressure and temp doens`t seems to be working correctly (at least in openwheelers) ... literally no difference in temperatures with minumum and maximum possible tyre pressures so I would expect some update in next TM ..
  18. It is the same for other cars. All things equal (track, air and ground temps), tyre temps vary in accordance with the way you drive the car and how stiff you set the springs and dampers.