Some people say that the devs make LFS tyre model in this way (especially in Patch Y/Z) so that there will be fewer drifters. Is that true ?
I can only think that tyres in LFS are preheated because Scawen is not confident about the effect on grip once the temperature gets for from the optimum.
Indeed it's not right. The closest real world example I can give you was during an endurance go kart race. I was flying before a fuel stop, it was a night stint, and after the fuel stop I belted out the pits and into the first turn and almost understeered straight off the track, the tyres had completely cooled and the lines and braking points I took before the stop no longer applied and it felt like driving on ice, literally I turned the wheel and nothing happened. By the end of the lap things where almost back to normal.
In LFS the surface tyre temperature raises and falls too slowly, you should be able to cool your tyres right off with 3-4 laps of easy driving, and currently that cant be done. Also, you should be able to get heat into your tyres in a lap or so of hard driving, and right now that isnt so.
My experience of tyre temperatures in karting seems consistent with observations of big car motorsports, slick tyre technology is afterall the same regardless of wheel size.
Naturally a smaller tyre will have less heat capacity, so will heat and cool more rapidly than a larger tyre, but then seeing as a kart weighs so much less, I'd imagine that would go some way to cancelling out the heating side of things, and the reduced surface area will do the same for the cooling. That said, the general consensus is still that tyres heat and cool too slowly.
That wasn't the point I was getting at though. I was thinking more about how much grip is affected, and how optimum slip changes with it (as I'd expect temperature to have at least a little effect on cornering stiffness).
That wasn't the point I was getting at though. I was thinking more about how much grip is affected, and how optimum slip changes with it (as I'd expect temperature to have at least a little effect on cornering stiffness).
I wonder if the heating up and cooling down is symmetrical? I dont know how accurate is calculation and what factors are taken in. But if devs made it longer to heat up but also slower to cool down to make cars drivable - then it is in fact drivable but the balance between is I think very important to weight it.
maybe off topic, but i wonder if they made some things the way they did, so the cars would be drivable, and easy. (not for realism)
in a sim you always do - some things have to be assumed as approximation to get wanted effect.
im saying they make it un-realistic in some way on purpose to make it either funner, or easier to play.
well, it is not about being unrealistic, it about not taking into account all the aspect that should be calculated - for optimalization reasons. So if not all the factors in tire temperature changes are calculated (rubbing, tire pressure, air temp, heat capacity) some of them have to be approximated
Surprisingly, this is also [post=1218025]discussed here[/post]
Surprisingly, this is also [post=1218025]discussed here[/post]
Frankly speaking I am curious if devs took mass of air into account in thermodynamical formulas, and in fact that is another thing that gives a lot of possibilities to set - but in the same time time-consuming thing to check. That is the amount of air flow under the fenders.
It is obviously possible to simulate the airflow and some kind of effect of that airflow on tire cooling.
But, the airflow on each car is going to be different based of the geometries and the aerodynamic features of each car. That's a lot of stuff to deal with. I would guess that some general formula could be used.
There is always going to be compromises in how things are done in the sim. Some stuff will be modeled dynamically, and others will probably use a general formula... a one size fits all kind of thing. I would think that airflow cooling of the tires would be one of those kinds of things.
kg/s per car or axis?
(logitekg25)
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Plus speed factor, angle factor, susp travel factor, draging, .................
consider pipe in airflow (where stream is Q=V/t - capacity per time - and speed of fluid is U= 4Q/pi*d^2 where d is diameter) - it is the same situation (compression level could be a kind of coefficient - the goal is not to simulate brake discs airflow intake cooling system but to simulate brake disc cooling effect), at least this representation is sufficient - angle factor could be easily taken into acount, susp travel could be probably neglected.
Some roumors say the next patch will bring rotating brake discs - I hope brake disc temps also (and brake fading) - the model is the same so I hope we'll get proper tyre temp changes also.
If we do get advanced brake simulation (like what I discussed here) then not only would air cooling effect brake temperatures but there could even be water cooling on the GTRs.
settle down with your complex math, and your rock and roll music:geezer::gandalf:
Well, I think it isnt complex math - it is few quite simple formulas that will result with mass of air per second taken from speed and some assumed coeficient for air intake property. And I reckon it as piece of cake comparing to physics problems Scawen did sorted out. 
What could be quite complex is a model for heat transfers in segmented tyre. Every segment transfers heat with every 5 to 8 neighbouring segments plus air inside and outside the tyre
And the calculations for heat balance could be quite resource consuming so I think some simplistic model would be welcomed. 
What could be quite complex is a model for heat transfers in segmented tyre. Every segment transfers heat with every 5 to 8 neighbouring segments plus air inside and outside the tyre
And the calculations for heat balance could be quite resource consuming so I think some simplistic model would be welcomed. which is why i think scawen needs an assistant or two, of people who are just as smart as he is (if possible) to help him out...he must be stressed!
short reconsideration - there is no need to simulate heat transfer between the neighbouring segments. They are too small comparing to contact patch. Second - there is no need to simulate heat transfer between each segment and air inside the tyre - it is better to get global factor for every segment. Third - the same applies for heat transfer between segments and outer environment. It will just look cool when with car standing still couple of minutes the contact patch (on i.e. hot tarmac) would be warmer than the rest of the tyre. But with expense of CPU usage 
edit: frankly speaking I didnt notice how does heat transfer between tyre and inside tube air work now - but I think the transfer between neighbouring segments could be done that way around: the whole tyre trades heat with air inside tube, thus each segment is affected.
edit: this latest idea would give strange effect - one flatspot could for a moment cool down the rest of the tyre till it settles in balance with air inside the tyre so it is not the bestest idea
and what I can think about is that every sector transfers heat with 3 environments: inner-tube air, outer air and average heat of the tyre thus the heat would be distributed to all the segments.
edit: frankly speaking I didnt notice how does heat transfer between tyre and inside tube air work now - but I think the transfer between neighbouring segments could be done that way around: the whole tyre trades heat with air inside tube, thus each segment is affected.edit: this latest idea would give strange effect - one flatspot could for a moment cool down the rest of the tyre till it settles in balance with air inside the tyre
so it is not the bestest idea and what I can think about is that every sector transfers heat with 3 environments: inner-tube air, outer air and average heat of the tyre thus the heat would be distributed to all the segments.
well, Im pretty sure devs will still make one of the best physics-best optimized sim out there. And brake fade would change a lot - especially at those long-straight-hairpin tracks where you will not smell the brakes but the next corner could be bit scary plus different characteristics and tricks for steel, ceramic and carbon discs.
where you will not smell the brakes but the next corner could be bit scary plus different characteristics and tricks for steel, ceramic and carbon discs.Wow, I had never noticed those teeny weeny blips in the corners of the tyre-temp pic.
How do you know for sure it's the rim and that it's modelled? Did you find it mentioned in docs somewhere? Does the whole wheel get modelled (heat reservoir with hugely more mass than the air in the tyre)?
Two things to add to this:
1) I'm interested in the tyre-wear vs. grip (and temperature) effect. LFS doesn't provide a wear-level indicator but wear does seem to influence the grip. I recently saw a guy do a spectacular lap (and some WR HLs do the same) after about fifteen minutes of abusing his tyres and then letting them cool down. And in a recent long race I clearly saw my tyres cooling down (with wear I guess) so I could abuse them more and not have them go red (wasn't 100% sure I had more grip though). [This, despite the fact that slicks have no tread pattern to move around less as the tread-depth drops. But OK, I guess less tyre-thickness might also provide less mechanical deformation and thus less heating.]
SO, I really want to understand how LFS models this tyre-wear effect. Anybody know? Does a high-wear tyre really give more grip? I've searched the forum and found little on this.
2) Tyre cooling: I have sometimes wondered if a car driven slowly (in LFS) cools its tyres more quickly than one left stopped on the track (and if the piece touching the track for the stopped car cools more quickly still
). Some half-hearted checks I made suggested that it made no difference (of course it should, as forced air cooling should be massively more effective at removing heat, no?). This point has come up already in this thread, but it's not clear if people are sure about it being absent. Anyone know for sure if this effect is modelled in LFS?1. a worn down tyre, does not produce more grip, BUT it will loose/gain temperature quicker as with the correct driving and can keep it in the max grip temp range for longer.
2. not sure had a few beers
2. not sure had a few beers
I know this mainly by messing around with Tweak and the tyre sizes. With a different rim size you see different parts of the tyre in the F9 view and it becomes more apparent. Also driving around in a high HP & several ton car heats the tyres just by driving (especially the sidewalls) which made me first notice that there's a rim down there on the F9 view. Seeing that a bit later the rim suddenly had the same colour as the sidewall made it clear that its heating is modelled.
As far as I know tyre wear does not affect grip at all. It does, however, affect the weight of the tyre (relatively sure) and the heat capacity (100% sure), the former meaning that with worn tyres you drive a lighter car which goes faster through corners, the latter allowing you to punish the tyres more since they can't hold heat as well and therefore won't overheat as readily.
The temperature however does have an affect on grip (duh), though the graphs are most likely outdated by now.
It does (click the picture on the right). Just not a numerical one.
dammit, i thought i forgot something, the tyre get lighter doh
I'm not sure if it gets lighter but it should get smaller.
Technical queries on tires
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