The reason we need the new tire improvements in GT cars

Discussion in 'General Discussion' started by Nieubermesch, Aug 1, 2021.

  1. green serpent

    green serpent Registered

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    I'm going to refrain from making conclusive judgements about what is realistic and what is not because I've long since realised I'm no expert!

    I just find when driving and especially racing in rF2, I find it immensely difficult to resist the temptation to drive in what might considered a fake or at the very least unconventional manner.

    I know when heading into a corner I can brake later than the ai and rotate the car on a dime to make the apex (exaggerated trail brake). The car doesn't just slightly yaw like an RL trail brake, it rotates like absolute crazy just breathing on the brake and a slight amount of steering.

    Mid corner, I know that if I load up just a bit too much steering input, then upon applying throttle the car will rotate out of the exit of a corner so hard it's like it's defying the laws of physics like some warp drive UFO.

    To drive at 99.99% pace in a smooth fluid manner in rF2, it takes immense talent, you need to have inputs that are God like, like doing surgery with a scalpel at 200km/h. But to drive at 99.50 pace, you can drive in a way that requires minimal precision, not a hell of a lot of skill, just aggression and good car control.

    I don't believe it's faster, but 99.50% is often good enough, and as mentioned I don't even need to bother about good lines, being smooth or much else. Just pure aggression and there you go, you're just a fraction off alien pace.

    Do I like it? No, as I stated it's just tempting to drive in this unconventional way.

    I notice in RL driving, RL drivers seem to correct even the slightest rotation IMMEDIATELY like split second. In rF2, I tend to let the rotation run it's course and let the car right itself naturally. Perhaps this is why I feel rF2 rotates too much, RL perhaps rotates just as much, but the RL drivers keep it on track like laser beam not letting it get away even for a fraction of a second, wheres I let the car yaw and don't fight it as much.

    I think this was a habit I picked up from when I would play back in the day and I simply could not control the straighten up of the car. The car would go in the direction of my countersteer (over correction) every single time. So I got in the habit of countersteering way less aggressively and sometimes not at all, and realised that the car would usually right itself naturally, not loose much time, and in some circumstances actually be beneficial.

    Edit: I'm not saying I'm a fraction off alien times, just trying to illustrate the point.
     
    Last edited: Aug 2, 2021
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  2. Nieubermesch

    Nieubermesch Registered

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    Nice lap too.
     
  3. Nieubermesch

    Nieubermesch Registered

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    Can you back any of this up in some way? Doesn't need to be conclusive, but at least suggest that what you are saying comes from substanciated evidence - not that I don't believe you, because it's either tires or aero that is definetly not right in some cars (maybe all (???) from what you are saying.

    Have to be honest that hearing about this leaves me more boomed than about tires, wich for me is quite more tricky to get right. When parameters so fundamental like that are missing in RF2 when it comes to aero then thats a real problem - bigger then tires, wich might actually not be having much of a problem if it's aero that's allwoing some of the driving styles...
     
  4. Nieubermesch

    Nieubermesch Registered

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    Those are the insane slip angles situations I was refering to also. The back of the car in those instances seem to be way to allowable with how much it can rotate without suffering the consequences of grip falling off enough. The car probably can rotate as much, but then it should be such a fast rotation that the rear, coupled with the aero plataform disturbance of such a fast maneuver, that the back should snap more out of stability. GT3 cars actually seem to have been made harder in this regard though, wich I like.

    What I also see in RL videos is that when the back is getting lost or some oversteer, it looks way to instable to not correct it and let this fix itself out like you mention in RF2. I think this is one of the allowences of RF2 in some cars that aren't realistic.

    It seems that sliding doesn't have to be the fastest driving manner, but pricesly the point that in some cars at least (with some bit of aero dependence mind you) it seems to easy to tweak some settings in setup and make the car so easy on the rear that you can throw it around like crazy that in the next lap after propper driving you are getting close to alien times and people instead of focusing on that are porpusedly focusing on that not being the fastest or not having been proven... It's not just about if it's the fastest, it's that it's an issue that extends to driving in any manner because it's allowable to let you be less focused and skilled then you should be in a crazy hotlap.
     
  5. Nieubermesch

    Nieubermesch Registered

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    Definetly all looked inside the realm of reality with some nice on the edge driving. Even if outside of realism in some instances, this I don't mind as it's too subtle. What one can see on other cars is a completly different story and why I want those tires implemented fast - implemented is adapted, of course.
     
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  6. leseb64

    leseb64 Registered

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    anyway there is no point in debating here if no physics dev comes to debate and no one has ever come to debate or clarify the subject of physics on the forum it's a shame...
     
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  7. Nieubermesch

    Nieubermesch Registered

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    Thats true :(
     
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  8. Sim_Player

    Sim_Player Registered

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    Gt aero problems specifically are well known in top level folks, and ofcourse devs know it as well.
    I have seen it in telemetry...doesn't take much effort tbh.

    The missing aero characteristics for body roll other hand....have good chances of being provable purely based on lack of hdv parameters plus on telemetry.
    I'm actually lossing df compared at rear only with both max arbs(very very minuscule number like under 20kg from memory depends on speed and car). looking at number alone probably it wouldn't look like as high priority case BUT the effect is wrong....aero roll sensitivity is real thing it is talked about in many articles (like fsae studies you find on google).
    Kunos dev Aris mentioned it couple of times infact he even made a video in past how stiffer arb might actually make cars stable.
    there are yt channel named kyle engineering he worked with mercedes F1 aero department, and he very very briefly mentioned it in some videos.

    The effects on body roll so far i gathered from all the above are

    1.Loss of Df on both axle due to loss of efficiency (sort of like how you lose df with more the yaw , maybe not on same level but it is noticeable to warrant such stiff arb rates , springs etc)

    2.something called Centre of pressure migration, which i don't fully get but probably CoP shifting back and forth making car unstable

    3.stalling underbody aero...which is very simple, you die :)

    and could be more problems with not have "flat" floor......which i'm not aware of.

    it is extremely hard to find study done specifically for this effect, people don't easily reveal their data hence i don't know how much actual DF should be gained or lost, but i do know i should gain it with less rolll and loss it with more roll.
    AND to be fair with stiffer arb i DO get tiny amount more at front axle bumping total df levels by whopping 5-10kgs lol but this is most probably indirect effect of less roll, as less roll car generally is kept lower at front and more slightly more raked.
    on other hand detach both arbs Lost me those impressive 5-10kg DF while gaining back slightly at rear....so in a way i can get maximum mechanical grip ,more rear wards DF and in my testing case despite detached ARB on both axle it gives rear easier time by putting more load on front outside tyre.(in max arb at both axle cases rear outside gets worked harder further worsening the effect) .. hence can run a click less wing.... this effect is wrong IMHO.
     
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  9. pilAUTO

    pilAUTO Registered

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    This post is sane.

    Frankly it's tiring to debate between users, without the intervention of physics developers.

    Tiring to see that 5 years after the arrival of S397, physics still has little interest, whereas it should be the number one priority.

    On the other hand, when it comes to talking about PIZZA on Discord, no problem, is not it !!!!!!!
     
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  10. Nieubermesch

    Nieubermesch Registered

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    That would extend to all cars then... I don't know how well many other sims deal with this, but it's disappointing to hear this, to say the least.

    I looked at the HDV entries and I didn't find anything on that and since you confirm it with the telemetry... If I reduce the rear wing to 1 in ACC and soften the ARB I end up with just a very difficult car to not simply snap oversteer on me and it happens precisely when the car is in body roll on a tight or fast turn. GT3 cars I think now have more sensitivity. Have you tested that? The reason why I ask real proof is because people here are always doubting such claims, even if something seems fishy in the handling that might suggest something is off with tires or whatever it might impacting grip dynamics.
     
  11. Sim_Player

    Sim_Player Registered

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    Yes i checked telemetry.
     
  12. Lazza

    Lazza Registered

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    Ultimately vehicle dynamics is very complex, and handling is a result of many, many factors.

    No doubt the HDV doesn't have explicit roll parameters, but roll isn't isolated - it's a result of the cornering condition, and at that point you have many other factors influencing grip, perhaps chiefly load transfer.

    There's also the question of design - you want downforce when cornering, and when cornering you have roll, so you're likely to try and maximise downforce with some expected roll rather than the perfectly flat condition. (it may not mean you don't still have peak downforce when flat, but its advantage may be reduced). The chart he-whose-name-often-changes posted earlier showed about 1.25%/deg lift loss, so it's not huge in what may be a relatively simple application (FSAE).

    I suspect roll parameters are a 'nice to have' that may ultimately have only very subtle effects on grip and handling, and would be dwarfed by any issues we currently see in tyre behaviour (hopefully less so with recent tyres) and aero height sensitivity - which itself could use better parameters.

    Finally, we need to bear in mind this all comes as a package. If you implemented perfect real life aero behaviour tomorrow in rF2, the simplified suspension system (in terms of modern cars and their attitude control systems) would probably lead to less realistic handling. Everything needs to work together, and sometimes if you concentrate too much in one area you lose the overall picture. I think we've seen that with some car releases, where presumably a number of tests looked good, but some overall effects (or edge cases) appear, at least from the outside, to be far from reality.
     
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  13. Binny

    Binny Registered

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    Do any sim devs listen to users and implement the fixes ASAP ? just look at iracing v8s loose rear wing boot or bonnet no difference in any aero nothing still drive as fast, they update every month but still no FIX. I get the impression they don't listen enough to the users, they have a yearly plan set out and probably a five yr plan as well.
     
  14. davehenrie

    davehenrie Registered

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    The general explanation is they catalog all issues, then sort by current priorities then file under categories like NOW, NEXT WEEK, NEXT YEAR. So if your simple hood issue affects the rF2 User Interface or Competition System or eSports...then expect a quick fix. If the hood issue only affects solo-offline users...then expect to wait...a long long time.
     
  15. green serpent

    green serpent Registered

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    It seems that IRL, they are correcting the slide like their life depends on it, that's the level of speed and urgency. In rF2, it's sometimes a case of I simply can't be bothered to correct in such a fast way because the reward seemingly isn't there (I think I would correct in such a way though if I was in an online race).

    I find that even without any setup tweaks I can still drive in a drifty way - the pedals almost steer the car better than the steering does. It's funny becuase this is the actual reason i started driving rF2, because it was the only sim that I felt trail braked correctly. But maybe it goes too far.

    As I said I don't want to make too many judgments on realism anymore for obvious reasons. I think people who drive their road car fast do have knowledge, but driving on a track with semi slicks feels different, then I'm sure slicks feel different again, and so on.

    I feel like though (subjective fantasy) that if you gave me the keys to a gt3 race car (do they even have keys?), in a couple of laps i could tell you if rF2 was at least ball park realistic (assumeing the setups where similar). I would go into a corner at moderate speed, apply just a bit of steering input and brake. Does the car rotate hard towards the apex? In slow corners (heck even coming out of my pit stall), does the car rotate like buggery on partial throttle with no wheelspin? Can I reliably mat the throttle mid corner and just control the beast through corner exit, or does it spin violently like a top? I'm sure there would be many grey areas, but I've driven rF2 so much I think I could tell pretty fast.

    I am always pretty dissapointed at the response from RL drivers when they compare it to the sim, their analysis is not very detailed. It's often "yes the sim is fantastic for keeping me sharp and learning my line, all the braking points are the same" or some such thing which is totally fine because they are in an interview or something. But it's never "In RL going into this corner If I downshift at this point and turn the wheel thirty degrees and brake at 50%, the car rotates this much." Eg specifics of the actual handling traits.
     
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  16. Nieubermesch

    Nieubermesch Registered

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    Everything you are saying seems to make sense to me, but I am no expert and prone to get things wrong. I've been hearing about wrong things with aero on S397 cars, but not quite extensively explained - even if it could be even more extensive... @Lazza confirmed that those effects on aero are not present so thats something out of the way. How negligent they can be or not as he says would remain for me to be seen. He gave numbers looking at the chart wich I didn't really look so well at since I am lazy and not really trained :D.

    I mean, it's a very complex system of interactions, cars that is. You also mentiom effects of wing degrees and what not and seemingly displaying wrong behavior. I want to take your word for it as there is something not quite right when driving and looking at some driving, but I would need to really be sure about aero behavior to say more. It's something more elusive to me then tires to be honest, although it might not be...

    The end result of seemingly softer ARBs for great mechanical grip and also lowering rear wing does seem like an OP combination if not being punished by the consequences that would have in reality. I can sort of imagine and have an educated guess at it, but I should refrain from stating squarly how I feel and think it should be.
     
  17. Nieubermesch

    Nieubermesch Registered

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    Yeah, it's frustating Sim Racing. It's very complex and all sims have problems. One sometimes gets too passionate about it - with good intentions though. Sometimes things just go a little to ridicullous in terms of the plausible handling of something and can't quite get ignored, be it to make cars easier of harder to drive. Not sure wich is worse. Will depend on the person I guess.

    You mean @Sim_Player ? Can we change our name in the forum? Is that a thing? I don't like mine so much anymore...

    You counter balance some of the detracting we see on the forums, with myself included, so do you have something you could say about aero effects of the cars @Sim_Player says are wrong in the things RF2 is controlling? He mentions more then just the influence of a missing aero rolling sensitivity, so I would like to hear a different view.

    Thanks and sorry if I get under your skin sometimes... :D:D
     
  18. Nieubermesch

    Nieubermesch Registered

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    Can't quite be sure one could really test the handling quite extensively to see if RF2 is realistic all the way, as we would probably crash the cars trying some of those feats... Some would be safer to try I guess :D:D.

    Yeah, ACC is known to have a slow slide that can get impossible to save, but slow. RF2 seems to have faster ones in most situations, but I feel they are a bit on the safe side, not quite accelarating as much the rotation of the car on a oversteet moment as I would think it should - on certain cars, mind you (GT or even some prototypes or cars with slicks by S397).

    They do seem to allow some bug slip angles that feel like drifting the rear around. Is this what you feel too? It bothers me more then certain easy slides too catch. Makes it a bit lazy and I don't have to be so sharp with my driving.

    Normally those real life pilots really do some general statement wich might be true or not, unfortunately :(.
     
  19. green serpent

    green serpent Registered

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    Speak for yourself, I wouldn't crash :p

    Simply put if I was tasked with giving S397 subjective real world feedback regarding handling, the first thing I'd do is go to a skid pan and test out how much 'brake vectoring' i.e how much rotation occurs during braking at various phases of the cars limit, below the limit, at the limit, slightly over the limit.

    You could be a bit more objective and collect data that measures the yaw, then compare with the sim.
     
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  20. Sim_Player

    Sim_Player Registered

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    This is also nice idea for name :)
    Surely i don't expect significant df gains or losses.Also this was a fsae chart these cars are small and not as restricted rule wise, on bigger gt cars and f1 these effects would be scaled bumping those numbers even more, probably 4-5% per degree which again not alot but atleast you won't get stupid results like when car is only caring about avg ride height and losing df on both axle despite having LESS roll.
    it is just looks ridiculous and unrealistic.
    You also have to remember not only df loss occurs with more roll, you get changes to CoP as well , can causing stalling etc etc could be more side effects.

    I do agree that engineering would make design with all the car conditions in mind.

    My point is simple we need aero physics updates (not just this specifically) otherwise it is not "fit" to simulate aero cars, which is majority of them are.
    ACC had to make completely new aero physics to simulate gt cars...which tells the gravity of situation.
     
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