Flatspots

Discussion in 'General Discussion' started by PLAYLIFE, Jun 17, 2013.

  1. PLAYLIFE

    PLAYLIFE Member

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    Ran a few online races before in the historic F3 mod, having a play with a few various things.

    The flatspots work and after abusing the tyres over a 20 minute race, they were cactus by the end. Quite happy with how the tyre wear is working, thumbs up .

    What I found most impressive was the FFB vibration becoming worse as the tyre became more and more 'flatspotted'.
    I seriously abused the tyres (accelerating with locked brakes, slamming on brakes at speed etc.).
    Through the corners whilst loading up the tyres, the FFB of my steering wheel was oscillating in what I would consider a very realistic manner. Very cool.


    (Edit: I am using a Logitech G27)

    However a few observations I noticed:
    1. The vibration from badly flatspotted tyres does not occur when driving in a straight line.
    I believe this to be incorrect. If you imagine a flatspot on a tyre like being a 50c/p piece, the vibration should be felt regardless of the tyre being loaded laterally through a corner or longitudinally on a straight.
    I can only assume that the vibration is only felt in the corners because that's when the FFB is being applied to the steering wheel. On a straight, there is very minimal FFB being applied hence the vibration is masked as nothing by the low FFB effects.
    Not sure how you could get around that?

    2. (This is a nice to have). After a tyre has been flatspotted, the next time you lock up the tyre will tend to find the flatspot and lock at this point again, making the flatspot worse. It tends not to create another flatspot elsewhere on the tyre (it happens but is less likely).
    Realistically, if you had 3 flatspots (small, medium, large), the largest flatspot will get increasingly get worse at a higher rate than the middle and similarly both at higher rates than the smallest.
    Not sure how possible this is to model in the game, and like I said, it's purely a nice to have.

    Ultimately, even if the above two points are not possible, from what I tested tonight, I'm quite happy with how rF2 treats flatspots. Definitely have to watch those lock-ups in a race!
     
    Last edited by a moderator: Jun 17, 2013
  2. Minibull

    Minibull Member

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    Are you using a G25 or G27? I remember reading things about how they can't produce very good effects when the steering is straight, which is why everything goes mostly smooth and plain going down straights. Maybe it has something to do with it, I dunno.
     
  3. tjc

    tjc Member

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    Firstly, the flatspotting is pretty cool, I agree. A nice feature to have in the sim.

    I`ve noticed your first point too PLAYLIFE, where the vibration is only felt when cornering and I also believe this to be incorrect.

    The vibration from a flatspot would most definitely be felt when travelling in a straight line (imo) and it just is`nt in rf2 atm...

    Hopefully this will get the attention it deserves. :)
     
  4. MarcG

    MarcG Registered

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    I've often thought about point 2, generally wondered whether the current tire model allows for finding the same flat spot or not.

    on a G25 myself with filtering set to 4, pretty sure I also don't feel them on the straights.
     
  5. PLAYLIFE

    PLAYLIFE Member

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    Minibull, thanks for the reminder, I've edited my original post and added the wheel I was using.
     
  6. speed1

    speed1 Banned

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    The flatspot effects are awesome and i'm pretty sure to feel the unbalance on the straight as well with the t500rs but I will check it again later.

    This effect is also one of the commendable and impressive effects of the tire model with very realistic feeling. :)
     
  7. Guy Moulton

    Guy Moulton Registered

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    When you flat spot one part of your tire, it DOES have a tendency to flat spot that same part of the tire each time you brake, however, it is possible to lock up on another part of the tire too. Different tires have different characteristics in regards to flat spotting. Try the Corvette and the Formula 2 cars- the very different tires in these series (different from the hard compound WCR60's tires) flat spot differently.

    With my T500 RS I feel a really bad flat spot in a straight line (it's like driving on a dirt road) with certain tires, however, WCR60's tires, especially the low power F3, are difficult to flat spot that badly. You will and can get a flat spot, but not as bad as the Vette or modern F2 tires. However, in a straight line, the effect of the rumble int he wheel is nowhere near as bad as it is in corners in any case.
     
  8. tjc

    tjc Member

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    Yeh, I`ve heard real racing drivers say (on TV) once a flat spot has happened it does indeed have a tendency to find that flat spot again...

    Btw, G25 here and as I`ve already said, don`t really feel the vibration of the flat spot(s) when on the straights.
     
  9. speed1

    speed1 Banned

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    I'm honestly not gone into the detail at the testdrive. However this effect appeared very plausible to me, at least with the ISI formula 2012. If it have the tendency to flat spot the same part of the tire or further shapes it, i really don't know, but you guys could be right because there was only one part of the tire visual affected. And yes the cornering vibe is much more brutal.
     
  10. PLAYLIFE

    PLAYLIFE Member

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  11. speed1

    speed1 Banned

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    I'm curious if a flat spot on the rear will be transfere the unbalance to the steering wheel as well. Btw the vid shows off how strong the vibe on the steering is while cornering. Looks more brutal as on straight like it is with the ISI Formula 2012. However i really don't know the degree of realism because i don't know those cars and tires but i like it and the dynamics of the tire model already.
     
  12. raekwon

    raekwon Registered

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    flatspot its at good stage!!! i can feel them well also in straights...i'm useing a GT3 rs v2.
    logitech g25 an 27 may suffer for the center deadzone...
     
  13. MarcG

    MarcG Registered

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    what Filter setting are you using? whack it right down to 0 and give it a try, I'll do the same later (G25 also) just to see if it is noticeable on straights.
     
  14. BlaringFiddle5

    BlaringFiddle5 Registered

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    Not sure if this is flat spotting or just in general overheating of the tires, but I was running the new ISI Formula masters 1.47 over the weekend at Malaysia. I could drive way faster than the AI during the race but was mid pack on qualify (AI set to 100% / 25% aggression). However, about 5 laps in my tires would have almost no grip! I'd have to pit. So I had to drive more reasonably and then could finish the race with no problem. Interesting! I've not seen this be the case in any sim I've driven or at least not enough to be a problem. Great STUFF!
     
  15. tjc

    tjc Member

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    I`m on 4... I`ll try it at 0 later though and report back.
     
  16. speed1

    speed1 Banned

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    Has nothing to do with the flatspot but also worth mentioning and wonderful perceptible during the ride over curbs is the deflection in the tire and not only on the patch area, also above under lateral load. As these forces act dynamically on the whole tire and even are above visible is impressive as well. Nice to catch with the open wheeler if you pay attention to the lettering on the tire.
     
  17. rhamm

    rhamm Registered

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    I'd forgotten about flatspotting until I was practicing at Heartland Park Topeka and suddenly had a vibration in the steering wheel after locking them up. It vibrated all the way around the circuit and not just in the turns. This is with a Fanatec CSR Elite.
     
  18. kaptainkremmen

    kaptainkremmen Registered

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    You'll suddenly notice how even the small lockups wreck your tyres. :) Your wheel will start to feel like it's full of sand in the corners after a few sloppy corners/laps
     
  19. MarcG

    MarcG Registered

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    OK quick test at Brianza, default Controller.ini with regards to FFB, G25:

    Filtering 4 = pre-lock ups no noticeable FFB in the wheel in a straight line apart from undulations in the surface. Post locks, good sense of flat spot FFB in turns as expected (and already known) and also the start of FFB in a straight line!
    I can hear (whatevers inside the G25!) rattling lightly and can just about feel it through the wheel, bearing in mind this was just one laps worth of lock ups (4/5) with Normal tire wear I can therefore imagine it would get worse over time with more lock ups so definatley there in a straight line for me.

    Filtering 0 = pre-lock ups no noticeable FFB in the wheel in a straight line apart from undulations in the surface which are certainly a bit more prominent than level 4. Post Locks, immense FFB in turns and much more noticeable in a straight line :) felt like the wheel was gonna explode so filtering reverted back to level 4 :p

    So yeah...conclusion is I do feel FFB in a straight line with flat spots, also noticed that when braking heavily you can feel the flat spots on the FFB begin to get slower (as the car slows) until there is a definate lock up and possibility that the same flat spot is found, but it's hard to actually tell 100%. But to me it does feel like the flat spots find themselves, which is nice but confirmation needed really.
     
  20. MarcG

    MarcG Registered

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    yeah I've noticed that before but when I saw this thread at work I questioned the Straight Line flat spot FFB, but now happy that's there too :)

    Also (and I've discussed this elsewhere) is there Sound to the flat spot? I can sweear I can hear differences from a clean tire to a flat spotted one...or am I hearing things?!? ;)
     

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