no u didnt. since the thread started.
no u didnt. since the thread started.
hmmm you really pinpointed something there that always struck me as odd in screenshots but i couldnt lay my finger on it ... it really looks like the sidewalls are streching out instead of merely deplacing whic i assume would be the correct behaviour with all the reinforcments in them
inner part when cornering in a way that loads the inner or lifts load from the inner part ?
i assume you mean lifting load from it ... but either way i think your wrong about the cetral part being the least deformable ... imho its the most deformable with the sidewalls and the sidewall/inner/outer transition being the stiffest parts of a tyre
dont forget that with high neg camber the insides heat up considerably under acell and braking
imho the effect of pressure on deformation under centrifugal forces should be rather slim
not sure if i i fully understand you but in case i do i dont think the model is necessarily wrong as such but its an effect caused by the simplification of using only 3 sections across, two of which are more or less directly connected to the sidewall which should cause the sidewalls to have much more effect on contact patch deformation than it has irl
i know but you can tell the exact amount of momentary camber (at least if shift-l does what is think it does) which leads to an assumption of loads on a rigid tyre (which i called geometric loads) ie loads without taking deformations into account which we can then use to analize how those loads changes under tyre deformation
not sure i get what youre saying there ... do you mean that the rubber also gets compressed and streched causing it to get thinner or thicker ?
Just to fan the flames, the readings you get via F9, they're pressures right?
Pressure being the force per unit area.
LFS gives three 'areas' in F9 view, left sidewall/edge(I presume) flat middle bit of tyre(I presume), right sidewall/edge (I presume).
Would it not be feasible that the pressure is so much higher on the sidewall reading because the sidewall area is so much smaller?
Surely the 'flat' udnerside area of the tyre that we're expecting to have more pressure on it does have the necessary forces applied to it, but because it has a much larger area (5x?) the 'pressure' displayed, is lower.
It's just a thought. I just don't think that we know the exact measurements for the three areas provided, and as they're giving pressure readings, that's some pretty important information we're missing.
Honey's results do seem a bit odd, but it's not enough of an issue to me for me to really look into it. Those car shaped graphics that I'm controlling, mimic the feeling of driving cars, and they're a great deal of fun to wrestle around 'tracks' against other people in similar blocks of pixels, so I'm happy. Best £24 I've spent.
Pressure being the force per unit area.
LFS gives three 'areas' in F9 view, left sidewall/edge(I presume) flat middle bit of tyre(I presume), right sidewall/edge (I presume).
Would it not be feasible that the pressure is so much higher on the sidewall reading because the sidewall area is so much smaller?
Surely the 'flat' udnerside area of the tyre that we're expecting to have more pressure on it does have the necessary forces applied to it, but because it has a much larger area (5x?) the 'pressure' displayed, is lower.
It's just a thought. I just don't think that we know the exact measurements for the three areas provided, and as they're giving pressure readings, that's some pretty important information we're missing.
Honey's results do seem a bit odd, but it's not enough of an issue to me for me to really look into it. Those car shaped graphics that I'm controlling, mimic the feeling of driving cars, and they're a great deal of fun to wrestle around 'tracks' against other people in similar blocks of pixels, so I'm happy. Best £24 I've spent.
i mean that from graphics it seems to me (i can be plain wrong) that the contact part is stratching, like if the outer part disappears
i meant: outer load > central load >> innner load (considering high deformation/displacement)
if you ever "played" with a tire out of its rim you could have experienced that the contact part is very hard to deform, the sidewall is very easy
yes, i considered, but i think i should repeat tests being sure to avoid these effects to have a more objective result
actually it is, but could also be easy modeled with a fictional incremental tire pressure that varies with speed...imho its irrelevant to our discussion
having only 3 sections is not an issue to me, more will only mean more accuracy,what i say is taht it seems to me that the functions behind the three sections are wrong or wrongly tuned.
about sidewall effect on tire load, that is what it is wrong, it's definately excessive, especially for a wheel with small rims like the xfg
I've probably lost track of what the discussion is about, all I really want to know is that with a stiff suspension, about 31 PSI pressure and -2.5 camber for the left front, in normal race driving, is it usual (read: possible) for the camber (or w/e it is in F9) to be as it is (more on the sides than middle) and should the tire temps be as they are (more on the sides than middle)
I'd have to disagree with that, for a few months, I worked as a Marshall at the Bedford Autodrome, and had a good days hands on experience with used slicks from the Formula Palmer Audis.
I'd say the opposite is very much true in those cases, the sidewalls were very very stiff, and the actual flat slick bit was much softer in comparison.
As for road tyres however, the difference doesn't seem quite as severe, however I don't have the same amount of experience handling un-rimmed road tyres as I've had with those slicks.
the images in this page http://www.rsracing.com/tech-tire.htm
show why i think the current lfs model is very wrong
show why i think the current lfs model is very wrong
slick/race tires are a whole different thing and i specified few times that for what i saw until now slicks are much better modeled into lfs
in real life it's definately not possible...and that's all the dicussion about
Ah so I'm still more or less with the convo then
Thanks 
hmm cant get my head aroungd the whole bias ply vs radial thing atm (im totally concentrating on group theory and channel coding atm ... got an exam tomorrow)
but just a quick observation for now ... its probably related to the general consensus that lfs tyres feel somewhat like bias plys
but just a quick observation for now ... its probably related to the general consensus that lfs tyres feel somewhat like bias plys
Before I even read further: that is very correct, and could be a very explanation of why this happens. There is a compression force across the width of the tire, which may be modelled now and wasn't before.
think to your exam is much more important
btw with the previous images at linked page i meant that either way lfs model is incorrect
You can't really compare these pics with LFS BF1. The tyres on the pics have a higher pressure (long race), and are still cold.
Darkone55 & Honey,
I only wanted to bring across that it is very hard to judge from visual observations if the tyre model of LFS is visualy spot on or not, let alone that is very hard if not imposible to determine from visual cues if the tyre physics are acurate. Most of the remarks in this thread indicate the same (slip angle, tyre pressure, weight, power/ throttle imposed on the tire, radius of the corner and cornering speed, grip level of the road surface, ...). The second thing is that while driving you usualy don't (at least I don't) look at the tyre touching the tarmac. If it feels right it usualy is modelled right. That reminds me of a mathematicaly correct moddeled car sim that felt insanely wrong, forgot the name.
I only wanted to bring across that it is very hard to judge from visual observations if the tyre model of LFS is visualy spot on or not, let alone that is very hard if not imposible to determine from visual cues if the tyre physics are acurate. Most of the remarks in this thread indicate the same (slip angle, tyre pressure, weight, power/ throttle imposed on the tire, radius of the corner and cornering speed, grip level of the road surface, ...). The second thing is that while driving you usualy don't (at least I don't) look at the tyre touching the tarmac. If it feels right it usualy is modelled right. That reminds me of a mathematicaly correct moddeled car sim that felt insanely wrong, forgot the name.
Luckily, we're not using visual observations, but instead are relying on LFS's built-in tire analyzing tools and data.
Unfortunately, that's not true. At least, it isn't when you're dealing with mutiple cars, of multiple sizes, weights, drivetrain layouts, and multiple setups. If the tires are not behaving according to real world physics then setups become guesswork rather than relying on real world data and adjustments that are known to work in reality. "feels right = modeled right" might work good enough for a game like GPL where the cars are all of similar size, power, and tire size. But in a game like LFS it doesn't work.
Luckily, the tire model in LFS is good enough that it seems to mask most of these problems. However; that doesn't mean that it shouldn't be looked at and addressed, if possible.
I saw some insane tires deformations while racing online with the LX6 yesterday. But I don't know how realistic it is. I remember when I had my crazy driving period at 18, a friend tried to follow me on a curvy downhill but told me later he slowed down because he was scared how my tires were deforming. I had cheap and narrow tires.
Nobody had any thoughts on my point about the fact the F9 readings display pressure?
Pressure being the force per unit area.
LFS gives three 'areas' in F9 view, left edge, flat middle bit of tyre, right edge.
Would it not be feasible that the pressure is so much higher on the sidewall reading because the sidewall area is so much smaller? So even if say the force was the same on the middle and the left edge of the tyre, the left edge would be experiencing a muc higher presure.
Pressure being the force per unit area.
LFS gives three 'areas' in F9 view, left edge, flat middle bit of tyre, right edge.
Would it not be feasible that the pressure is so much higher on the sidewall reading because the sidewall area is so much smaller? So even if say the force was the same on the middle and the left edge of the tyre, the left edge would be experiencing a muc higher presure.
Cue-Ball,
Quote:
"However; that doesn't mean that it shouldn't be looked at and addressed, if possible."
Unquote
Agree and point taken.
Quote:
"However; that doesn't mean that it shouldn't be looked at and addressed, if possible."
Unquote
Agree and point taken.
sorry i wanted to reply but forgot...
pressure is uniform, F9 readings should be the mechanical load against the tarmac
Pressure is uniform? Even if you model it over different areas??
You do realise he's talking about the pressure of the tyre on the track, not the internal pressure?
You do realise he's talking about the pressure of the tyre on the track, not the internal pressure?
pressure is by definition a gas/fluid thing, on tarmac there is "force" not pressure...well there is the pressure of air, but i don't think that's what he intended
EDIT: he inverted the force and pressure concepts (using force for internal air, pressure for tire against tarmac), so the reasoning should be the exact opposite as he did
OK, what I was trying to get across was:
If those graphs are showing the 'pressure' on the tyre. As in, they're displaying the force per unit area being applied to each part of the tyre by the road.
I didn't mean anything to do with the pressure inside the tyre.
Hope that helps a bit.
If those graphs are showing the 'pressure' on the tyre. As in, they're displaying the force per unit area being applied to each part of the tyre by the road.
I didn't mean anything to do with the pressure inside the tyre.
Hope that helps a bit.
I can apply pressure with my hands on my desk
*demonstates*
It is a force over an area. Just like a gas exerts a force over an area due to the pressure...
*demonstates*
It is a force over an area. Just like a gas exerts a force over an area due to the pressure...
Wow, I can do that to!
*acquiesces*
But what do the F9 graphs display? Is it the pressure from the force of the air inside the tyre, or from the force of the road pushing on the outside of the tyre?
If it was that inside the tyre, then when you parked on the roof, the bar wouldn't go to zero, as there'd still be force on the inside of the tyre from the air? Or so I think
You could argue that we don't know the scale of the axis of the bars, so although they appear to go to zero, they could just be below the lower limit of what is displayed, and as such, we can't really make any guesses as to what they mean... They could be inverted and spread across 0.0001 units for all we know
Tyre deformation a bit severe?
(165 posts, started )
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