Understanding rear wheels slip influence on steering torque

Discussion in 'General Discussion' started by mantasisg, Dec 30, 2018.

  1. Jihemme

    Jihemme Registered

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    Hey all,

    Actually, the steering wheel shouldn't be the cue you trust when you are over / under steering. Wheels sound shouldn't neither...

    At best, those 2 cues are confirming factors (and FFB should help you to correct it).

    The only cue you should trust 100% of the time is your sight.
     
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  2. mantasisg

    mantasisg Registered

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    I have exact same opinion, it is not too easy to explain it.

    As always most knowledge is in aircraft world:
     
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  3. mantasisg

    mantasisg Registered

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    I wonder about wheelbase length now, am I right to assume that shorter wheelbase will give better/faster oversteer response through the wheel ? As much as it seems it does work like that in rF2. It makes sense because for longer wheel base for same slip angle rear end will be able to step out greater distance. And steering wheel is slower to start spinning into a slide. When you drive cobra, which is shorter you can pretty much let steering wheel lead you when oversteering, Howston G4 for example feels like it needs more of your own initiative.

    In conclusion, seems to me that faster FFB/steering torque response makes it tougher to be smooth and precise, with longer wheelbase it is easier to be smooth responses are slower, but you also have to steer wheel more yourself, rather than expecting commands from FFB. Basically I think that longer wheelbase will require slower reaction than short wheelbase, but also will be less suggestive.

    Maybe thats one of the reasons why modern F1 and FE cars are as long as football field, in addition to trying to imitate jet fighter aircrafts.

    Also I wonder if it is right to assume that the "seat feel" would be more important for short wheelbases, and less important for long wheelbases ? It is tricky to say, in short wheelbase you'd move out in lesser distance when oversteering, but the yaw rotation would be quicker ?

    Also I suppose seat position is also very important, I remember reading or from some documentary that Autounion Type C drivers had a lot of difficulties with controlling oversteer, as they had seats at the very front, and the car was long. That would be totally true for visual cues, and probably the seat feel as well.
     
    Last edited: Jan 14, 2019
  4. Korva7

    Korva7 Registered

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    I think that effect on ffb is mostly caused by different suspension/steering geometries. Higher caster for examble makes the car correct it self more strongly.

    Quote from some random website:
    "Caster really helps a drift car by making it self-steer better. When you start to drift, you can simply let go of the wheel and let if feed through your fingers, and the car will counter faster than if you were steering it yourself. "
    http://www.superstreetonline.com/how-to/chassis-suspension/modp-1201-basic-drift-chassis-setup/
     
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  5. mantasisg

    mantasisg Registered

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    Hmm.. that page is for some reason unavailable for "some EU countries".

    Yes indeed it has to do a lot. It would be interesting to try exactly same vehicle just with different wheelbase lengths. There are multiple reasons for self aligning, seems like it isn't fully understood, as for example from this video



    Of course there is no oversteer there, but just caster stuff.

    Interesting thing is also that caster angle alone is not the whole thing, it also is important where the axis goes in relation to the wheel, as in this video.

     
  6. Nitrometh

    Nitrometh Registered

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    Car dynamic is really interesting. I had some lectures years ago about all that stuff.
    We went to Boxberg to drive on the different test tracks. It was fun as hell :)
     
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  7. Korva7

    Korva7 Registered

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    Wheelbase for sure have somekind of effect on the oversteer behavior of a car.
    But if you imagine two versions of the same car, other with longer wheel base and other with shorter, making the same angular movement (rear end stepping out in same way), i don't think there would be much difference in what you feel in the steering of the car.
     
  8. mantasisg

    mantasisg Registered

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    Maybe... I'm basing my assumption mostly on the logic that for the same angle longer wheelbase will be able to slide bigger difference, thus more time, thus more time to react. On the other hand I speculate that it might not give such obvious response through steering.

    But it might not be more important as tire and geometry properties of steering.

    I had an idea, I don't know if I shared it already, positive mechanical trail for wheel could be something similar like wheelbase is to whole car.
     
    Last edited: Feb 9, 2019
  9. mantasisg

    mantasisg Registered

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    *I have decided to share these thoughts there, I was replying in other thread, and realised that it is major offtopic there.

    -In reply about synchronization of FFB with car.-

    To me it is a shame that the very first release of ACC was labeled as wrong handling, as in my opinion it was very right. My perception is either worse than most, or better lol

    I wish the right path of simulation will win.

    After playing a lot of rF2 and a lot of first build of ACC (I spent 40 hours with lambo in Nurburgring) nor AMS, nor AC doesn't feel right to me. Not bad, but not right.

    I would describe two different typical sensations/handling types of simulation:

    -1st. Don't interfere with FFB too much and just guide the steering. Thats how AC and AMS feels to me.
    -2nd. Don't rely on FFB too much and just let it guide you while you do the steering.

    Probably most effect on that has output time on FFB, naturally faster output requires less input for a driver. It has advantages and disadvantages, it wrecks you if you are not aware to catch the steering in time and countersteer, but it helps to initiate many many corrections if you only don't fight the wheel when it is helping.

    It is difficult to say whats wrong, and what is right, because both could be right or wrong to certain degree, cars have different steering mechanics.

    *Thats where it comes to this topic. Cars have differences. To be completely fair, thats why I like rF2. Cars have bold differences. Sometimes people dislike them, and thinks it is an issue. Like for example understeer feel of Mercedes GT3 car, or torque steer like sensation with Honda Civic. Some cars in rF2 feels more like the type which handling depends more on driver inputs and less on steering outputs, and vice versa.

    Right now I am playing about equal amount rF2 and AC. It is always strange to get from one to other for a couple of laps before getting used. AC is fine if you realize that you simply shouldn't interfere FFB too much, and rF2 is fine if you realize that you have to be more active with a steering.
     
  10. mantasisg

    mantasisg Registered

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    Scratch that, AMS feels very good. I had a problem with settings. For some reason "Auto steering" was enabled. It ruined everything. Also interesting was that with different cars it had different level of "damage", it didn't change Puma road car very much, but completely ruined V8 supercar.
     

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