Logitech G27 high speed odd FFB vibration

Discussion in 'Bug Reports' started by Spitfire1, Oct 16, 2020.

  1. Spitfire1

    Spitfire1 Registered

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    Is this a bug in the tire model or do i have too low or too high air pressure in the tires? Or maybe the tgm is resized wrong? Which one is it most likely?

    To give a better idea of this then it is like if your tire is very low on air and you try driving it at higher speeds than is good for it and the steering wheel will vibrate like crazy and give these knocks to your hands.
     
    Last edited: Oct 16, 2020
  2. davehenrie

    davehenrie Registered

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    could be clipping of the ffb forces. try reducing the individual ffb number. If it is tire construction, that would be an indication of too soft of a sidewall. Now remember, rF2 has a flat spotting computation. If you flat spot your tire while braking, it will shake the fingernails off yer hands!
     
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  3. qusimano

    qusimano Registered

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    i remember massive vibration and rattling with logitech wheels, when you flatspotting tyres under braking.. if this is the problem, the only solution was to use a value of 9 (cant remember exactly) for the smoothing filter, wich as the name suggest, smooth the ffb (not the best solution)
     
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  4. Spitfire1

    Spitfire1 Registered

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    Thanks guys i will have to find a solution or leave it like it is.
     
  5. davehenrie

    davehenrie Registered

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    one way to test if you are flat spotting the tires while braking is to put the tire on a car with ABS brakes. It is darn hard to flat spot a tire when the abs is on full. Then run some laps trying to duplicate your original shaking laps. If the shakes do not appear, then it's a flat spot. If the tire shakes on the ABS car, then it's another issue.... double check your suspension is all tidy and connected maybe?
     
  6. Lazza

    Lazza Registered

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    Or just turn off tyre wear, then you get no flatspots. Any strange speed related effects of the tyres spinning will still show up.
     
  7. Spitfire1

    Spitfire1 Registered

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    It is almost like the tire has maybe 60-70% of the air volume it should have and then when you drive quickly lets say 250 kmh then it all starts to vibrate and kick back at your hands randomly. I don't get this in rf1 with same radius of tire and same rim radius.
     
  8. Lazza

    Lazza Registered

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    rF1 relies on the spring rate you give in the .tbc. rF2 generates the spring rate based on the tyre geometry. That's just one example. It's not a simple comparison between the two.

    That spring rate in rF1 also doesn't depend at all on the tyre or rim radius - it's a standalone figure. Again - rF1 isn't a physical model.

    Your suspension damping obviously needs to be tuned somewhat to what the tyre is doing, or you'll get oscillations. It's possible the tyre isn't as suitable for your geometry and rates as the .tbc is, or the geometry itself isn't as good.

    Might be something totally unrelated. I don't know.
     
  9. Spitfire1

    Spitfire1 Registered

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    Yes i get it it's not a physical model in rf1 but slip curve tables and is a physical model in rf2 with no slip tables.

    It is highly likely the tgm is simply an odd shape and not quite in shape of a tire more like closer to egg?(overinflated) or even underinflated or simply i have some settings wrong in the ffb or the g27 profiler or the last option which i hope not and that is a bug in the game.
     
  10. Lazza

    Lazza Registered

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    If this vibration shows in telemetry from the game then you can rule out your G27 settings.

    The tyre you've resized would be best suited to some range of loads and pressures, but rF2 is fairly forgiving across wide ranges. I feel like insufficient fast damping would be your most likely issue, but that's just a guess.

    I wouldn't expect it to be a bug.
     

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