Tires inner and outer temperature

Discussion in 'General Discussion' started by Pablo11, Aug 8, 2015.

  1. Pablo11

    Pablo11 Registered

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    Ok so you all saying how good is rfactor 2 but i see this problem from the begining and it seems like nobody care anymore about it .
    How is this even possible that with such a low camber there is up to 30 celsius temp differents between inner and outer tire and that suppose to be no more than 10 if im right?
    How is that accurate in real racing and why there is no fix for it and ISI is doing nothing to change it?
    How do you set up the car then if those fundamental settings are showing wrong?
     
  2. Drathuu

    Drathuu Registered

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    Short version -

    Body roll in cornering will load up tyres, if you have nearly no camber, the car will roll in the corners on the suspension putting load on the tyres.. they tyres will deform and compress with the outer tyre carrying more load and hence heating up. You can offset this with camber, but that will effect steering and tyre wear / heat on straights as you dont have a full contact patch and braking. You can tweak with tyre pressure or change suspension settings to manage roll, but this will have positive and negative effects on other parts of handling heat and wear on the car.

    In short.. I havent seen much wrong at all with temps and tyre modelling.. if anything its improving every single build.

    Once you get a feel for car, tyre and suspension dynamics as the card rolles over the wheel base and they tyres deform, you will have a better understanding of how to tune the car to even out loads... That said, the car may then handle like crap, so its always a trade off one way or the other... the goal being to make the fastest car (for sprints) - or quite fast case for longer races depending on your stop strategies. Ive seen some run slower cars but tuned to conserve tyres and skip stops to win, depends on how you drive and the type of race your in.

    Note the tyre loads on the inside and outside.. (not much bodyroll on this car over the tyre (open wheeler) hence lower COG.
     
    Last edited by a moderator: Aug 8, 2015
  3. matf1

    matf1 Registered

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    I care :) It is good, but I don't believe anyone suggested it's perfect. You are asking questions here though instead of proclaiming, so let's see if we can help you with that.

    The difference between temperatures is simply an indicator of the suspension geometry configuration .
    Camber has the most obvious and direct influence on this indicator but all parts are important. No, there is no golden rule for temperature spread and in rF2 unlike other simulators it will change based on track conditions and tyre life.

    ISI have Released 3 vehicles with the new contact patch and assisted with the 3rd party Palatov.
    Is the problem with one of these cars?

    For the older cars, it is known they do not have the most up to date model and discrepancies are to be expected. My advice for that specific circumstance is to rely on feel rather than data.
    Yes that will be a problem for endurance races, but everyone is on an equal playing field.

    -ISI do not apply fixes, they model something correctly. If it is wrong then the model is incorrect, or unfinished. Both of these scenarios would be quite evident to them and a source of focus you can bet on.

    How do you setup the car.
    If the spread is 30 degrees, I'd suggest that we have too much load on the end or corner in question.
    Low tyre pressures and/or soft suspension allow the tyres tread and sidewall to move around much more. This movement will always generate heat which in turn reduces grip, which generates heat.
    What you can do is better balance the suspension geometry and the chassis and if it's still not enough then you must look deeply at your driving style.

    There is no doubt however there are some vehicles that exacerbate this symptom and it is clear nothing is to be done but wait for an update.
     
  4. David O'Reilly

    David O'Reilly Registered

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    My friend you have an unfortunate way of wording your question as a kind of accusation to "you all".
    However I will try to help you.

    I agree that the tyre temps across the tyre show a bigger delta than would be expected in real life.
    However try to focus a little more on the 3 mid depth "rubber temp" readings rather than the surface temp readings. The surface temps like IRL will fluctuate wildly (friction AND cooling from air). They move so much that it's hard to get a meaningful picture.
    In real life tyre pyrometers and are inserted deeper into a tyre to get this mid rubber temp. Over a lap the pattern is easier to follow.
    The core temperature is also very helpful. It will show you whether your front-rear grip balance is good. (too hot means too much sliding at that end, you want as even front-rear averages as you can get).

    Getting back to you main question. The temperature delta across the tyre is still a very good tool to look at camber but not at pressure in all the cars. The middle temp still reads too high in many cars in RF2. If you chase an even temperature spread with the middle of the 3 temps bang in the middle of the other two it won't work.

    In practice camber is a suck it and see approach. ##
    Less camber brakes and accellerates better, more camber might handle cornering loads and lean better.
    Move it one way and see if its better through the whole corner. (delta best plugin works well). If it's better , move it more till it isn't. Move back as required.
    Rear camber (in a rear wheel drive car) will be somewhere around half way between the front camber and zero due to the rears need to propel as well as corner the car. If you move camber too high (negative) you will get nice cornering but poor accelleration and braking.
    It will be (as always) very much track dependent. EG Spa with some long high G corners tends to rewards more camber than say Monza where accelleration and braking are more valued. (Longitudinal loads vs lateral loads).
    Rear camber is more sensitive.

    Pressures are still a bit of a mystery but they have an impact. The fronts will give you more feel due to pneumatic trail in FFB and work well with a little more pressure.
    I stumbled on the fact that in the ISI Masters a one step harder compound works better with 3 clicks more pressure.

    In my experience Camber and pressure dont take that long and have much less impact than that of slow bump dampers, springs and diff lock and getting a car set nicely.
    With the former look at the tyre temps in the car status monitor. The end thats getting hotter-lower the slow bump and or springs. (there are conseqeuences and limits but I wont spend 3000 words here). The end that's too cool do the reverse.
    If there is nice behaviour mid corner but unintended behaviour on entry or exit thats where the diff comes in,
    If it wont turn-in, lower diff on coast, if its snaky on exit increase diff on power side. The diff is the straight jacket within you will allow the suspension to do its job. If its mis- behaving you tighten the straight jacket.

    Have fun
    Signed
    "You all"

    ## We are not alone in this suck and see method, this in good reading...http://949racing.com/using-a-tire-pyrometer-949-Racing.aspx
    The central theme of the above article is that we should find what works really well and then make a note of what the data said rather than expect the data to lea us to what will work.
     
    Last edited by a moderator: Aug 8, 2015
  5. Ozzy

    Ozzy Registered

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    Also remind, the temps in garage screen are temps at the moment you hit escape. This usually happens after rolling on the straight or something like that.
    The temps you are interested in is at the time the tire is loaded in the corner. So keep an eye on the outside tire temps while cornering. If you want to know it exactly, use telemetry analysis to get the whole picture.
     
  6. David O'Reilly

    David O'Reilly Registered

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    and its only the surface temp....:)
     
  7. marvelharvey

    marvelharvey Registered

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    Very off topic, but it seems that you guys might know the answer: do the brake discs dissipate heat into the tyres?
     
  8. WiZPER

    WiZPER Registered

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    Right, RF2 has several levels of tyre temps - only surface temps are shown ingame, use motec or other tools to observe rubber and carcass temps.

    As for surface temps, just drag a piece of rubber fast across a surface while forcing load on it - and you'll notice how quickly temperature will develop, locally.
     
  9. boblevieux

    boblevieux Registered

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    I don't think the disc heat the tyres through the rims.
     
  10. TJones

    TJones Registered

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    Hi, dev team is very aware about the capabilities of the new CPM tyres.
    What Tim wrote at 04-06-15:
    (Source)

    There is no "fast fix" posssible. Instead it's just continuous hard work, it's a very complicatet and time consuming process.
     
  11. WiZPER

    WiZPER Registered

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    I'm particulary puzzled by the temperature rise on a sliding tyre with close to zero load - but I think that is what's being mentioned by Tim. So yes it's not perfect, but still the best damn tyre model on the (low budget) market! :)
     
  12. David O'Reilly

    David O'Reilly Registered

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    Looks like you missed my post above.
     
  13. Lazza

    Lazza Registered

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    Agree. The clue is there are no parameters defining the heat transfer, which you'd logically need in order to model different vehicles. ISI very occasionally puts in a hard coded magic number but generally if there's a calculation modelling something, there'll be parameters governing it.
     
  14. WiZPER

    WiZPER Registered

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    No, not at all, we were just both replying to Pablo's comment I think :) I very much agree with you... (hence the "right")
     
  15. Pablo11

    Pablo11 Registered

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    Thank you to all for the answers. Its very interesting read.
    Sorry for the way i was asking. I did not really want to accuse anybody here just point the problem that still exist in my opinion.
    I do believe everybody has a different driving style and if you constantly over driving the car in corners the tires read will not be accurate.
    But i also believe i have a smooth driving style and no matter if i push in corners or not and whatever setup im running the temp spread is always too big and im using motec to read that as well .
    I mostly play EGT . Nissan GTR , EVE SPark series and im always confused how to set up the car because of the tire temperature spread:)
     
  16. Korva7

    Korva7 Registered

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    I remember someones here talking how it takes something like 10 laps before temperatures stabilize.
     
  17. Lgel

    Lgel Registered

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    I said that for pressures in the new DW12 thread.

    Cheers
     
  18. Korva7

    Korva7 Registered

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    :D Okay. That wasn't quite right then.
     
  19. patsax95

    patsax95 Registered

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    off topic, but which cars currently have the new CPM?
     
  20. Korva7

    Korva7 Registered

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    karts, ac cobra, palatov and Dallara DW12
     

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