Flat-spotting: S397 please include option to disable this!

Discussion in 'General Discussion' started by Rapala, Jan 23, 2017.

  1. TJones

    TJones Registered

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    Yes, my post might not be very useful for the OP, in this short form and of course its very subjective.
    My statement above is based on impressions i've got, only by watching races. I have (almost) no real live driving experience, only some Kart racing (hobby) back in the 90th. But when you've seen that many practice sessions, qualifyings and races over the last years. You should estimate pretty well, if some who had a spun or lock up while braking, is forced to enter the box to change tyres.

    I think this particullar feature is almost perfectly implemented in rF2. In AC it's defiantely to weak, automobilista not bad but not completely on the level of rF2 and in Iracing there are no flatspots at all to my knowledge.
    ISI devs spend many hours to develop this feature to this level of realism, IMO it would be almost absurd to bring in another function to tone it down or switch it of. Besides that it would be unfair advantige over others in MP, in SP you get used of a more rough, arcade-like driving/braking style that has not much to do with RL.

    I can only can give the OP the advice to try following:
    - train to drive/brake properly.
    - if you flatsopt tyres, drive instantly and slow back to box and change tyres, just like in RL.
    - increase FF-damping, which mean of course a less senstive FF.
    - use a brake pedal with a loadcell sensor.
     
  2. Will Mazeo

    Will Mazeo Registered

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    I believe in rF2 this is built in the tire what makes it more advanced, well rF2 tire model itself is far more advanced, while in AMS it's not at all, look for mods that have it implemented you can easily modify this, ofc I could be mistaken :D
     
    Last edited: Jan 28, 2017
  3. PLAYLIFE

    PLAYLIFE Member

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    I've been watching motor-racing since the early 1980s, everything from F1 to MotoGP to rally. I too think that I've got a reasonable idea, however, my point was that observation is no replacement for actual evidence and by that I mean real tangible data. I don't think it will be possible so we will have to be happy with 'reasonable guesses' which is good enough for me. My only point is that there is no way of knowing what is more or less realistic that is backed by hard data.

    My general feeling is that flat-spotting is poorly understood in real motor-racing and therefore it will be less understood in any simulation, especially when the average Joe such as myself can create mods without a full compliment of real data.
     
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  4. rhamm

    rhamm Registered

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    I wouldn't mind if they added this feature for offline but only if it was something they could do in a day, including testing, simply because only a few clients have asked for it so there are more important things to work on.
     
  5. patchedupdemon

    patchedupdemon Registered

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    I've only been on iracing just over a year but requests for flatspotring are nearly a monthly occurrence.not wanting it is just an excuse for not putting the effort into being able to avoid them
     
  6. Emery

    Emery Registered

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    Why? Flatspotting is caused by brake lockup which is the result of the wheel not having enough downforce to create enough friction between the tire & pavement to overcome the braking torque. It also happens when the car is sliding sideways and the tires aren't spinning fast enough to rotate the tire's footprint.

    rF2's tire model includes the base friction, the hysteresis & tearing of the rubber, the sidewall stiffness, the tread stiffness, the abrasiveness of the track, polygons placed around the tire for measurement (horizontal & circumferential), and a bunch of other things that I can't even think of off the top of my head. The rF2 model is certainly adequate for simulating flatspots. rF1 model lacks many of these features, but particularly the circumferential polygons which is essential.

    If you want to know how well tire behavior in general is understood, I suggest you read Tire & Vehicle Dynamics by Pacejka(https://www.amazon.com/dp/0080970168).
     
  7. DavidG

    DavidG Registered

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    I’m all in favour of this suggestion. I have RSI problems with both arms and cannot cope with the juddering flat-spot vibration at all. In fact, as soon as I flat-spot a tyre, I have to immediately terminate the session (or at least go back to the pits to change tyres, when appropriate). This can be very annoying when it happens near the end of a race. Turning off tyre wear, or deadening the force-feedback, are poor solutions. In fact, as I tend to run short races, I would prefer to have tyre wear accelerated, which only exacerbates the problem. An option to have a different, softer, type of effect, or to turn down the severity of the vibration, would be most welcome, if this is possible. I would also like to see less severe flat spots wear down over time, which, if it is happening already, doesn’t seem that obvious to me (but then I've only ever been able to run for a limited time after any flat-spot has occurred).
     
  8. Lazza

    Lazza Registered

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    Please guys, read more than the first post. The wear that causes flatspots, and the subsequent vibrations, are simply part of the tyre model. They aren't separate and can't be switched off.
     
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  9. Euskotracks

    Euskotracks Registered

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    Maybe a special filter to better avoid rattling could be introduced. I am not sure what kind of post processing is performed with actual smoothing but maybe a more effective one could be achieved.

    I have a few experience with signal treatment and would love to do some trials with lazza's DAM plugin to see the results. While I think that it will be possible to understand the behaviour by making dome tests it would be nice to know if this sounds interesting to the devs and would like to provide some info about it.
     
  10. Thepharcyde

    Thepharcyde Registered

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