Rear tire patch contact area and grip

Discussion in 'General Discussion' started by Joe, Sep 11, 2015.

  1. Joe

    Joe Registered

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    I agree, after spent a little time on the Nissan GTR CPM car. Big time for rF2 with CPM.
     
  2. Joe

    Joe Registered

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    In the past, they have tyre model, but not contact patch "model". Or they might have, but so simplicity they might not refer to being "modeling".
    CPM could be biggest forward step in terms of their tyre modeling. I never felt rF2 cars rear tire realistic. this is why many do not bother rF2 sim. With CPM, there is a hope.
     
  3. WiZPER

    WiZPER Registered

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    I really can't take you serious... there has been no competitor close to rf2 on this front, neither before or after CPM-updated cars - "Many" :rolleyes:
     
  4. stonec

    stonec Registered

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    rF2 tires, no matter CPM or not, are miles ahead of competition, excluding perhaps iRacing. Since day one, there is no car that feels rF1 for me in rF2. Many of the historic cars are still at their initial version and they are still miles ahead of rF1 cars imo.
     
  5. Joe

    Joe Registered

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    Read my quote carefully before heating up: "I never felt rF2 cars rear tire realistic. this is why many do not bother rF2 sim. With CPM, there is a hope. "
    Is rFactor 2 the best Sim around? Yes, I think so IMHO.
    Does rFactor 2 non-CPM rear tire feel realistic? No, NOT at all, IMHO.
     
  6. msportdan

    msportdan Banned

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    I agree joe. pre-cpm, I prefer gsc handling and tyres.
     
  7. stonec

    stonec Registered

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    Read the quotes above. If you don't deal with big changes of tire load, CPM is likely not going to make a huge difference. That is probably why it wasn't modelled in first place. The big step was to move from mathematical tire model (rF1/GSCE) into first-principles model of real tire (rF2), everything above that is refinement of existing model. For me, latest Brabham feels fantastic and it doesn't have CPM. Some other updates over the years have made a bigger change imo.
     
  8. msportdan

    msportdan Banned

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    maybe by the numbers yeah there was more authenticity going on, but by feel.. well that's a different thing. We expect different things. lets just leae it to personal taste.,:)
     
  9. Spinelli

    Spinelli Banned

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    Can't go by "feel" if you're talking about the physical feel from FFB. E.g., I can change 20 lines of FFB settings (RealFeel.ini and/or Controller.ini) and have (e.g.) 5 different "versions" of FFB which won't change a thing when it comes to vehicle dynamics; it just changes what you feel and/or how little/much you feel of those. Physics behaviour is still the same, just like how physics are the same if you play with a keyboard, or no FFB, or watching a video, or playing with a joystick, a gamepad, etc.
     
  10. yusupov

    yusupov Registered

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    latest brabham does have CPM, doesnt it??

    msportdan....not going to comment...:p
     
  11. Minibull

    Minibull Member

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    Yeah, the Brabham does have the updated CPM iirc.
    The whole CPM thing is just us users latching onto that term and using it to describe the change. They had a contact patch model before, you can see it working with the TGM display. This is just updated, like any of the other aspects of the sim.
     
  12. WiZPER

    WiZPER Registered

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    Yup on all accounts...
     
  13. msportdan

    msportdan Banned

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    nope still will stand by by original comment..

    For example, i know the pre cpm cars have far more numbers pumped into them, than the GSC cars, but for me those cars feel better, i dont know why they are just more believable for me, from my real world experiences, which does include a single seater, rf cars feel like theres no grip on offer at low speed and theres no confidence to place in these.

    The cpm cars however, i feel much more confident in... tyres feel like rubber not just hard bits of wood.

    Im sure the BT doesnt have cpm as it was before the april cpm insertion date.

    but thats just good ol msportdan opinion!
     
    Last edited by a moderator: Sep 18, 2015
  14. mrsmr2

    mrsmr2 Registered

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    BT20 doesn't have CPM.
     
  15. Minibull

    Minibull Member

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    Yep, my mistake there eh. They did something with the tyres though, I'm sure.

    Dan, yeah they do feel very slightly different to me, but it's not a day and night change. Just very minor changes, but I can see bigger changes with the way the patch is working now.
    I was mainly referring to the way people seem to be thinking this is a whole new thing, and there was no contact patch before lol
     
  16. msportdan

    msportdan Banned

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    yeah i understand minibull, i know theres lots of placebo effect in sim racing. But i wont lie i really like where rf2 has gotten lately. Ive had my issues with rf2 as many will know. but for some reason i thinks its finally all coming together and people can maybe take rf2 as a full assed racing sim, with complete features!
     
  17. Alesi

    Alesi Registered

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    "real road" in iracing is very very advanced and very interesting. ISi should implement something like that to their real road - it would be great. cause no track not alive in rf2 (temperature of the track on sun, under the trees...).. just grip become better the more laps u go but no influence on grip by the temperature
     
  18. Joe

    Joe Registered

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    If this is true, then why did they call "Contract Patch Model --- CPM" this time, why not before?
    If this is true, then Why did they state in the new NGTR: "Brand new Tyre (CPM)...", instead of saying "Tyre update or such..."?

    the ttool shown no way to illustrate if they had a CPM before or not. It shows tyre model with some nodes in the cross section and some variation. CP could be treated in a very simple approach without any true dynamic modeling. Detail of CP model is not visible in the ttool (no CP variables to be displayed). CPM is intrinsic in this regard.

    --------------

    Anyhow, takeaway from this thread as we have learned that rF2 offered NEW Tyre from their "New" CPM going forward (from Apr 1, 2015). Now I will spend more seat time on those new cars instead.....
     
    Last edited by a moderator: Sep 18, 2015
  19. Ronnie

    Ronnie Registered

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    Yup. "Wet" code implemented. So they are first tyres IRC that had some parameters for cooling, grip, adhesion etc for wet conditions. That's what they did with the tyres. ;)

    Still waiting for my beloved Speed 8 and GT500 GTR. Stock cars will be fascinating for me. I will sink into them deeply just to see how different approaches and solutions influence these cars. Can't wait.
     
  20. Minibull

    Minibull Member

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    If there was no contact patch model before, you wouldn't be driving on anything.

    If you open up the TGM display, on the old cars and go driving, you can see the four contact patches. Shrinking and growing under different loads, changing as the tyre rolls over in a corner. It just doesn't behave as good as the updated model
     

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