RELEASED-wip Mercedes-Benz W125 0.79

1937 grandprix car

  1. righi78

    righi78 New Member

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    First, of course, a great job. Only the rolling moment when accelerating is far too exaggerated. The default values are by far wrong. That's not how it really is. Even at the slightest acceleration, the car drifts away. In real life, nobody could drive this car. Please adjust this.

    Here it is fine:
    (this is the Pay Mod you know it i guess) These physics are good!
     
    Last edited: Jun 4, 2019
  2. mantasisg

    mantasisg Active Member

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    I don't even...

    How do you know if the default values are wrong ? And what values exactly are you talking about ?

    I suppose you drive the real car on pace, if you claim that the car is not how it really is. May you elaborate how do you assume that ? Have you done any specific observations, that we have failed to ? Or is it simply because you failed to master the car in three minutes ?

    Also what is the slightest acceleration ? Define me that.

    IRL some great men was able to drive the car perfectly fine, even in rain.

    If you prefer that cheap conversion, then it is ok with me, use that. I guess if you have pay for then it is automatically better. P.S. that one looks quite throttle sensitive too.
     
    Last edited: Jun 4, 2019
    shivo, ltcars and luchian like this.
  3. luchian

    luchian Administrator Staff Member Pilot RLR

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    Regardless of you being right or wrong, this kind of "feedback" is useless.

    Speak with data, give examples instead of general remarks. IF you give general remarks, then you need to argument/demonstrate somehow (real life experience, real measurements, feedback from people that actually drove the car, etc). Without these, no matter how willing a modder is to listen to you, it's impossible to modify something for the better.
     
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  4. mantasisg

    mantasisg Active Member

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    I have also forgotten that I never updated the car. I just never found myself working further on the model...

    But I have tweaked it slightly, after the feedback from Gary, which was on point. It does give the car a bit more grip.
     
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  5. mantasisg

    mantasisg Active Member

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    mantasisg updated Mercedes-Benz W125 with a new update entry:

    Version 2019

    Read the rest of this update entry...
     
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  6. luchian

    luchian Administrator Staff Member Pilot RLR

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    Totally true :lol::banghead:
     
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  7. Vintagedriver1

    Vintagedriver1 New Member

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    I do have two free versions of this W125, maybe the other version is more of your taste, found it simple by Google and/or Youtube. I never drive such a car, but I have seen lots of Youtube documentaries about pre-war racing and you see that these drivers are constantly correcting the car and drifting the car into the corner. Bad road surface, small & primitive tyres and bad suspension, in combination to high power output, I suspect a deadly combination to your road handling.

    Would like to ask the designer on what he did exactly, change in the update?
     
  8. mantasisg

    mantasisg Active Member

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    Most recent changes were making tires a bit less like a marshmallows.

    I keep trying to make the car less floaty, but so that it wouldn't be too grippy at the same time (because I'd like laptimes to be realistic). There is nice recent video with few episodes of Valtteri Bottas getting it on the limit. Although it likely drives on better rubber than there was actually in 1937, it still should be relatively similar, because most likely grip is similar, but the difference is at wear. You can see the car doesn't drive at an excessive angle constantly when abusing the throttle, but it does seem to have relatively good grip. I don't mind to take a big banked turn at Deutschland Ring with relatively straight steering and doing part of the steering with throttle, but at some point I can even calmly add more throttle and start kinda drifting it. It feels wrong and it looks wrong in replay. It was an issue since the beginning of this mod. I think it got greatly reduced since then, but it still happens. I don't know how much of this is a result of some wrong tire modeling from my side, and how much is from hardcoded side of Assetto Corsa. Something feels off about combination of driving force slip ratio and slip angle at the rear, feels like if I could have great deal of both at the same time...
     
  9. fughettaboutit

    fughettaboutit Moderator

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    great stuff
     
    Last edited: Oct 18, 2019
  10. mantasisg

    mantasisg Active Member

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    mantasisg updated Mercedes-Benz W125 with a new update entry:

    Car handling update

    Read the rest of this update entry...
     
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  11. Vintagedriver1

    Vintagedriver1 New Member

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    Sorry but my content manager can not load this car.

    Untitled.jpg
     
  12. mantasisg

    mantasisg Active Member

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    Have you tried to redownload and reinstall ? Delete what you have now at first, so you'll not get somehow confused. I don't think that these files are missing from what I have uploaded.
     
  13. Vintagedriver1

    Vintagedriver1 New Member

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    I will redownloaded again and before install delete the old one, strange but the old version was without problem.

    Edit, it is working, now after an redownload.
     
    Last edited: Oct 27, 2019
  14. Rodolfo

    Rodolfo New Member

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    I had the great luck to download this mod, many, many thanks for your work. Now I can't wait to see his opponent from AutoUnion
     
  15. Vintagedriver1

    Vintagedriver1 New Member

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    There is an D and C version, maybe not perfect but good as an AI opponent. While at Racedepartment forum a member is trying to design a real beauty.
     
  16. mantasisg

    mantasisg Active Member

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    Yes, Gary has pushed Type C model to a very high level. Miles ahead comparing to mine W125 how it is currently. Worth to mention, that he did animations for W125. Also before him I also received help from @Tibor Solyom. I always had some weird fear of animations :D

    I wonder how the Type C will handle. Those pre war gp tires actually had grip that was ok, maybe not as good as post war tires (like the ones on maserati 250f), but they were ok. Their main issue was that they didn't last. Actually I suppose majority of their grip did come from wear, as it is one of the source for grip, besides adhesion and mechanical keying. Going for such old, and completely different tire and car, must be great source to uncover some unknown variables in terms of how tires work.
     
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  17. Kondor999

    Kondor999 New Member

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    I really enjoyed the challenge of the 0.5 version, but 0.777 seems to be a (large) step backwards in terms of the tire modeling. The tires are now much less progressive and there's a near-instant drop-off of grip at the limit. As a result, the 0.777 W125 is much harder to control than the Auto Union Type C, and that simply cannot be correct.

    The problem is that once the tires start to slip, they lose grip very suddenly, leading to a driving style that doesn't really match the historical record. In-period, you can see the drivers power-sliding out of low-speed corners with little difficulty. With 0.5, this was challenging to do, but achievable. With 0.777, you have to adopt the same driving style as you would use while driving on ice: Never, ever induce any wheelspin early or mid-corner. That may be the style of driving you're seeing in modern videos (where the driver is being extremely cautious in their priceless museum piece), but that's not how these cars were driven in-period (judging by the limited video evidence we have).

    One advantage of these old tires should be that the grip drop-off is fairly gentle (tall compliant sidewalls, narrow width tires should have relatively gentle breakaway characteristics, although low maximum grip). I'm curious why you thought making these tires intolerant of slip angle was the right way to go. I know nothing about the tires of the era, but I do know that, in general, narrow tires with tall/soft sidewalls tend to lose grip much more gradually than wide tires with short, stiff sidewalls. That's certainly been my experience IRL.

    Thanks for all your hard work.
     
    Tibor Solyom likes this.
  18. mantasisg

    mantasisg Active Member

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    One of the problems with slow grip drop-off is that it induces sliding super early and then half of driving with this car is almost constant diagonal sliding, which if not feels that much wrong from cockpit due to not knowing how it should be, it looks absolutely off from replays. One of the goals were to put car in good grip for broader range of performance. And as much as I have seen footage from the time, they do not drive these cars diagonaly the whole time, they look driven like you expect from a car, with occasional gentle powerslides, which also fits into logic that tire performs better up to higher peak, and then peak is just sharper.

    I understand that it is unpopular choice by me, but I believe it is right. Interestingly tire should feel more controlable, untill it is not, and require some anticipation and reaction to maintain it in its operational slip and temperature. But I guess the concentration part is the one which is unpopular in simracing. It is non modern low sidewall super wide tire, but it is also not that sharp IMO

    I did not very much driving of these both when Autounion was released, but 3/4 laps with W125 were clean, and none with AutoUnion. So I am not entirely sure if Autounion is that much easier, but if it had same tire logic then it would be even more so, surely. To me this sharp tire logic is not a big trouble, I just have anticipation for it, and now that I shouldn't be drifting it and bring it back sooner than later, and thats it. One thing that helps AutoUnion is that it has more load on rear tires, and also a bit less power, naturally it has better traction than W125.

    I disagree that current tire doesn't match the behaviour as seen in footage from 30s. I also disagree with comparison to driving on ice. Ice is like the opposite of sharp, and previous tire was much more like ice - start sliding early, and slide a lot more. Current tire simply has MORE GRIP and then more sudden loss of it (which you don't like), thats all to it. It generally has more grip. You can induce wheelspin, anywhere, but just have to be more careful with it.

    I agree about the logic that tire with tall sidewalls and narrow tread should be more gradual to loose grip. But it is not everything. We don't have wide 30s tire example as comparison. And the tire had grip then, I think it is general misconseption that these old tires were super slippery, their worst property was their durability. I think with a grip that is not "nothing" a tire is logical to have higher grip peak, but then it of course needs faster fall-off to maintain the net total of grip, otherwise it becomes unrealistically too quick. And to repeat... these properties I find to match old footage of these cars. Finally speaking of being gradual, I think we forget how non gradual is the torque of this car, being over 900Nm, well unless you have rather gradual foot. I would agree about increasing slip angle slightly, I have reduced the slip angle indeed, but I did it so to battle ice skating of the car, Ironically you call out this tire to be icy, even though it is completely different story. I would agree with a bit more slip angle, but I don't want to allow it to skate everywhere unrealistically. I would give the tire few degs of slip peak angle back, if I could somehow avoid it becoming a fairy tale super high degree drifter at high speeds. The car will have the grip, as a result it will have drop - off. You ask me to remove grip, and remove drop-off. In my perception older tire is ice, not the new. Our perceptions are so different.

    Overall it is interesting to do such tire, because it is exploring some piece of tire puzzle, that was never done by Kunos. But I am sure they would have made a tire to be very gradual.
     
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  19. garyjpaterson

    garyjpaterson Member

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    Just a quick thing to add - do not assume the Auto Union is correct - the physics were developed independently and I didn't do much or any testing to check for balance between them (as I didn't have time).

    Personally I think the AU is a little on the 'easy' side of where it should be, though that is a suspension thing not tyres, simply by being more aggressive with the rear roll centre will make it harder.
     
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  20. mantasisg

    mantasisg Active Member

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    I also didn't drive a lot, I was quite busy with some other projects and stuff. But when I checked in Deutschland Ring they were within a second of pace, I also saw few videos on youtube where a guy did a lap with each at Classic Spa and there it also was within a second. So I suppose they quite match already. But needs more testing, I believe AutoUnion could be overdriven more and would be bit faster, even though the rear end geometry is not forgiving.

    I am looking forward to get more fun with those cars in AC. I would also revisit few tire parameters, but I am sure that I would stick to the logic that tires shouldn't skate all the time, but rather drop-off later and harder.
     
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