Another video which shows tyre deformation in action.
This time throughout a whole lap onboard with Szabolcs Róbert (LFS name:ProexRobi, who is Norbi's team chief btw) in a Renault Clio racing car, where one of the 4 cams facing backwards shows the right front tyre and suspension as the car goes into corners and riding on kerbs at the Hungaroring.
According to Norbi they used to set 2.1-2.2 bar in the Pirelli 195/45 R16 tyres which goes up to some 2.7 during a race.

http://rapidshare.de/files/18757613/1lap.avi.html

Quote from Marki :

Another video which shows tyre deformation in action.
This time throughout a whole lap onboard with Szabolcs Róbert (LFS name:ProexRobi, who is Norbi's team chief btw) in a Renault Clio racing car, where one of the 4 cams facing backwards shows the right front tyre and suspension as the car goes into corners and riding on kerbs at the Hungaroring.
According to Norbi they used to set 2.1-2.2 bar in the Pirelli 195/45 R16 tyres which goes up to some 2.7 during a race.

http://rapidshare.de/files/18757613/1lap.avi.html

can somebody upload this file to another site? i used up my limit..

Quote from Ball Bearing Turbo :

Honey, the phenomenon you describe about the middle part of the tire is attainable even in a straight line on a real car - with too low a tire pressure. I don't know if it happens for the same reason during cornering, but that shows that it's not physically impossible for your "vacuum" (although it's not) effect to occur IRL.

it happens at very low pressures when pressure is comparable with other forces and the tire model is much more complex and as i said that's not the case i'm talikng about, even at slighly low presures it must not happen

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Casual drag racers often lay a patch just for the purpose of observing the said patch, looking for the phenomenon you desribe, or the reverse (for over inflated tires). I don't know if LFS models (nonexistant) centrifugal force on the tires, I thought in a thread somewhere that it did, but I was informed that it does not. That may account for something.

i'm talking about road tires not slicks, i precised it from the beginning

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We also do not know if the visual representation in LFS is precisely what the physics model is generating... What I mean is that the graphics engine may or may not relate to the physics with 100% accuracy. In terms of the "amount" of deformation, I realise it has too, but I mean in terms of the structure of the tire.

infact i repeated many times that my guesses came from the F9 info wich are representation of the dynamic tire phisic model of lfs

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Pictures from RL don't show much for either side without the appropriate information unfortunately, and we can find pictures that seem to prove either side but they prove nothing really.

from the inclination of cars on screenshots it seems that they were taken at high lateral G

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And honey, driving at 50km/h is not relevant. You can still generate massive forces at 50k, 100k, whatever. I'm tempted to mount a camera on my car and find an empty parking lot hehe

i believe that when you drive into traffic you and other people are not driving at maximum G, compare your usual driving with a similar riding into lfs and watch replay with F9 info

Quote from NotAnIllusion :

The point is that it happens even at 2.2 bar which according to Honey (I don't know, don't blaim me if it's not right ) is the max recommended pressure for that type of car & tires.

It does happen at 2.2 bar, I know because I tried it in LFS. I went all the way to 2.8 bar when it stopped happening but the result was that even with optimal temps and -2.5 camber for the fronts and -4.1 for the rears in every single corner at Blackwood GP, and even if just gently swinging left and right on a straight the slope of the live camber inverted and a huge amount of understeer one doesn't get with lower pressures.

I don't know enough about tires to draw realistic conclusions, but what I do know after trying out with road_normals and slick2s is that there is no advantage to running with higher (realistic?) pressures, in fact I still did significantly better with low pressures one would have used in the P/Q patch.

Oh and found an interesting link
http://www.toyo.com.au/Pit%20Lane.htm

thank you for taking the time to actual test it and answer honestly.
actually recommended pressure for an xfg like car is 2.0 bars, 2.2 is the maximum recommended.

this patch feel much more unrealistic on road tires because this huge problem with the new deformation model joint with previous problems (unrealistic maximum grip at very low pressures + unrealistic temperature/grip model for road tires) make this patch very weird and this only problem of deformation cancels the others huge improvements of this patch.

i really hope scawen talks a bit more about the tire model, so that feedbacks can be more precise and constructive and better let's all hope that the recent agreement with intel/sauber/bmw/michelin opens the doors of more technical data to lfs also for road tires.

Quote from Honey :

i'm talking about road tires not slicks, i precised it from the beginning

So was I, hence the term "casual" drag racers. Infact that test works with street tires.

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from the inclination of cars on screenshots it seems that they were taken at high lateral G

You still don't know all you need to know about the situation, no matter what.

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i believe that when you drive into traffic you and other people are not driving at maximum G, compare your usual driving with a similar riding into lfs and watch replay with F9 info

Alright I will.

Can someone though please explain exactly what Honey is saying? I may be misunderstanding what he's trying to say and I want to be sure so I know what I am testing.

Thank you.

hes saying that it stikes him as peculiar that the middle of the tyre gets less load than the outside and the inside

That's what I thought, thanks Shotglass.

I don't think at first thought that such a thing is totally peculiar, however I will oblige him and test it.

Quote from Honey :

i invite everyone that sys it is right, to take the xfg put tire pressure at 2.2 bars (the maximum recommended for car like xfg), put 3.5 live camber (that's huge!), hit F9 and drive slowly around blackwood you will be driving all time on sidewall (and this is wrong) but what is impossible is that the outer side of tire has 90% of the weight and center part has the less amount wich is against any phisic law!!!

would people do a test before speaking?

things start to behave normally only at maximum tire pressure and maximum camber.

on cars with wider tires this abnormal situation is much less evident.

i think that slick tires are simulated quite well (i guess it's because of bf1) but road tires are unnatural! not to mention that the longitudinal grip is much much more than RL (while the lateral grip is too low imho).

i understand people are happy because formula car are now easy to drive, but if someone take the time to test the xfg, would see it too.

greets, u just wasted me 2 minutes of testing.
i saw nothing un natural. the loaded part of tyre was the correct one.
i tried both with positive and negative cambers at the pressure u told us to test. i saw nothing unusual except lfs own unique innovative and cutting edge tyre code, but i knew that well before.
it is not complete, but it is complete enuff to refute such basic claims as i've seen written here. seems fab at this stage to me.
if u wanna help and be constructive so be it,but please, with facts, figures (not invented) and reference material to compare.
even being so lowpoly it translates a very nice feeling of bendin rubber and will continue to improve (lfs is a w.i.p. product).
formula1 "seems easy" to drive mostly at hi speed due to incomplete aero. its not complete. its not really tyre related, and u can try have a go with just undertray to see its not the tyres giving too wide grip angles...
it is very real for such a fast implementation from start to finish, imho.
atm its mostly the unfinished aero making the tyres look too good (but they are not as good as lfs aero makes them look )
even with aero simplified (for lfs aimed standards) i still dont see the few people that complain about it "being easy", being competitive in the charts...

the burnouts issue is mostly a lowspeed lowload prob and has been reported to death (fortunately better) and somewhere in the future i suspect will be tweaked (would look good along false starts).

tyrecode featurewise, other stuff in the pipeline aswell but none are as basic or crude as some ppl suggest (not to say shout). its mostly subtle stuff planned (from what i know) that i doubt much ppl would even notice the difference in a blind test...

I think I've been able to replicate Honey's results. Here's what I'm seeing:

Using Bob's old "Road Going" setup on the XFG the car has 34.1 psi front, 32 psi rear, +1.4* camber front, +1.0* camber rear. At these settings the front tires are loading the sidewalls more than the center section (you can see this from the grey bars above the temp reading. The center line is shorter). The center of the tire doesn't seem to get even pressure until about 42psi or higher, give or take. This seems to be the crux of the matter.

However; I was NOT able to replicate the camber/loading problem that he's talking about. But, I think I may have figured out why he's seeing it. When you first change settings, then hit OK to enter the pits/race/track/whatever the car is first set down and the camber is all wacky. According to F9 the outside of the tire is loaded the most, even with positive camber. This is because the springs haven't yet been compressed for the first time (the car just "appeared" on the track). You have to drive a few feet for them to settle. Once you do this, the "problem" goes away.

In the end, I think Honey has a point. You shouldn't need 42+ psi of pressure to make a normal road tire give an even footprint across the tread. I know that I run about 32-34 psi in my car on street tires. Running 42 psi would definitely be overinflated and would cause the center to wear faster than the edges, if not cause a blowout. The question is, how does this actually affect tire temps and wear? I think we'd need a long section of freeway in the game to really know for sure, but perhaps Scawen can at least look into this.

i can second the little oddity in the loads you see on usual road pressures too ... hard to say whats wrong in the model though ... maybe its just the lack of balloning from rotation ... maybe something else

Quote from KiDCoDEa :

even with aero simplified (for lfs aimed standards) i still dont see the few people that complain about it "being easy", being competitive in the charts...

"interesting" that you say i'm wrong about lfs tire phisics because i'm not in the top charts of formula cars...moreover, fast has nothing to do with phisic knowledge (strange that nobody asked me to prove i'm fast when i graduated as engineer or when i passed the exams for inscription at the professional engineer's book...), moreover "easy" not = "fast", moreover i'm talking about xfg, moreover if you see my old stats, you will see that 50% of races i was on the podium...i think it's not that bad for a girl like me who spend only few hours per week at lfs...
if you can prove that i'm wrong please humor me...

Quote from Honey :

a girl like me

big mistake posting that info openly round here

Quote from Shotglass :

i can second the little oddity in the loads you see on usual road pressures too ... hard to say whats wrong in the model though ... maybe its just the lack of balloning from rotation ... maybe something else

it's "just" (mainly) the biasing of the function that relates pressure to tire load; in previous patch was almost correct, now it's always working as the tire had a very very very low pressure.
what makes it really odd is that the function grip/pressure has totally opposite bias comparing to reality, so basically it is no longer possible to find even fictional settings in lfs to make the car behave like in real life

the point is that when cornering even at quite low pressures (let's say 1.6 bar) the normal situation is (A) with the new patch at almost every tire pressure the tire load while cornering is (B), which is phisically impossible.
and please consider that (B) into lfs is much more exaggerated, here i made it small for clear purposes.

also if you put much negative camber and do some fast laps you will see that is not the left part that heats up but only the right one and that's another very odd thing because of a bad discrepancy inside the lfs tire model (that wasn't so with the previous patch)

its really hard to say where exatly the problem arises ... maybe its just some parameter (like cetrifugal forces ... yeah i know it a virtual force yadda yadda) missing and the models works better than wed expect right now hard to tell when going just by looks without any hard data on how the tyre deforms

when said behaviour happens its usually with positive momentary camber (check shift-l to see live camber) (main "geometric" load on the ourside) and significant outer-sidewall deformation
now if we assume that the inside sidewall deforms less than the outside the contact patch has do fold somewhere which happens to be towards the axle most of the time

Quote from Honey :

also if you put much negative camber and do some fast laps you will see that is not the left part that heats up but only the right one and that's another very odd thing because of a bad discrepancy inside the lfs tire model (that wasn't so with the previous patch)

left/right being inside or outside of the tyre ?

shotglass and cue-ball:

lack of balloning effect per pressure? yes i agree. Maybe its lacking a bit (just a tad, but it is). i did the tests and usually am very picky about that on previous patch. i know it was spot on then, coz i recall doing many many tests.
For the Formula1 patch i didnt test for balloning/loads vs pressure.
But wtf does that got to do with the dreadful english long rant posts that honey does?
live camber 3.5?!? wtf does camber help in seeing this?
quite the oposite.
flat terrain like autoX, and 0 live camber is what anyone needs to test balloning profile.
tx for pinpointing this small subtlety that can surely be improved in future patches (as the past can prove).
cya


ps: calling outer and inner parts of the rolling tyre surface, "sidewalls", doesnt help anyone...

Quote from KiDCoDEa :

lack of balloning effect per pressure?

nope im talking about balloning from high rotational speeds ie centrifugal forces streching the tyres outwards

Quote :

ps: calling outer and inner parts of a tyre, sidewalls, doesnt help anyone...

the idea is that the loads on the inner and outer parts of the tyres are to a large degree influenced by sidewall rigidity whereas the load in the middle is mostly influenced by pressure

Quote from Honey :

not that bad for a girl like me

girl, boy, or something inbetween, you'll get exact same treatment from me in a forum, dont worry.
I dont do positive-discrimination due to gender in a game, so please dont do it for yourself either. No need, and tbh my comment about competitiveness was a bit more broad than your person.

Quote from Shotglass :

its really hard to say where exatly the problem arises ... maybe its just some parameter (like cetrifugal forces ... yeah i know it a virtual force yadda yadda) missing and the models works better than wed expect right now hard to tell when going just by looks without any hard data on how the tyre deforms

when said behaviour happens its usually with positive momentary camber (check shift-l to see live camber) (main "geometric" load on the ourside) and significant outer-sidewall deformation
now if we assume that the inside sidewall deforms less than the outside the contact patch has do fold somewhere which happens to be towards the axle most of the time

your considerations about shift-l data and guesses, seem to confirm a graphical thing: the tire seems not to displace, but rather stretch...if it really so (in lfs) then the problem could be that the inner part is not deforming, while in RL the displacement of inner part makes the inner part "lift" even at very low pressures...considering that the central part of a real tire is the biggest and the least deformable, it always have much more load than the inner part (let's remeber -> when cornering...)

The inner part surely do deform. Have a look in 'wheels' view and you see it very clearly.

Edit: reread your post. Disregard this post, as it's nonsense...

Quote from Shotglass :

left/right being inside or outside of the tyre ?

left is outside right inside considering the left tire while cornering right...hope i made myself clear...sorry

Quote from Shotglass :

nope im talking about balloning from high rotational speeds ie centrifugal forces streching the tyres outwards



the idea is that the loads on the inner and outer parts of the tyres are to a large degree influenced by sidewall rigidity whereas the load in the middle is mostly influenced by pressure

1) there is no centrifugal code per wheel yet on lfs (been requested many times). according to feedback, thats planned for future. the effect that force produces on tyre profile should be linked to pressure, but tbh i dont see modern tyres turning to jelly bags at normal range pressures. i recall a sim that tried to fudge this effect with dreadful results for the old ferrari gto from the early 60s.
Nowadays tyres are a bit dif

Quote from Shotglass :

...
the idea is that the loads on the inner and outer parts of the tyres are to a large degree influenced by sidewall rigidity whereas the load in the middle is mostly influenced by pressure

my concerns are that if this is true int lfs tire model (as it seems to be) its sadly wrong, because even at very low pressures (let's say 1.6 or 1.7 bars) those effects, must not show at all, but it must rather be "simply" pressure/compression problem

Quote from Shotglass :

when said behaviour happens its usually with positive momentary camber (check shift-l to see live camber) (main "geometric" load on the ourside) and significant outer-sidewall deformation
now if we assume that the inside sidewall deforms less than the outside the contact patch has do fold somewhere which happens to be towards the axle most of the time

shift L is a very simplified schematic representation. it is not the whole story of whats happening.
about "it has to hide somewhere" comment, i understand what u are saying, but u should also blend that comment of yours, with another, "rubber has some elastic properties", so the "fabric on one side" doesnt necessarily has to be exact same amount as on "the other side" in order for center to remain flat. much less on a material that doesnt have same properties on traction vs compression. try it on ya cotton tshirt, for a not-so-great example .