Tyre deformation a bit severe?

[danowat]

Trying to get used to the new physics on the FXO this morning, and I notice the amount of tyre deformation I am getting.

I would assume that the tyres fitted to a car like the FXO would be low-profile high performance tyres, if that is the case, I certainly wouldnt imagine that you would get this much deformation IRL, heck I am riding on the sidewalls round most of the corners.

The pressures are high enough, I suppose my main question is, this deformation, is it just a visual effect, or are the tyre physics deforming that much?.

(loving the patch BTW)

Dan,

[Tweaker]

Yeah it might be a bit too extreme, just to show off that feature.

People are suprised by the feature, and like to see it. I guess if it wasn't so extreme looking, it wouldn't be noticeable. But for the sake of making things a bit more realisitc, this could be toned down a bit.

I have seen pictures where the tires look like they are falling off like that, where the rim's edge is visible, but it wasn't so extreme like in this pic, since the actual tire's structure was still intact, just squashed down. This however is flexing and pulling.

[danowat]

Yeah, thats basically what I thought, it is accenuated to show the effect, rather than the actual tyre physics deforming that much, so visual rather than physical?.

Dan,

[Scawen]

The pressures are high enoughHow high? Default?

[danowat]

2psi down on default RACE_S set, which is 32psi, mine are at 30psi.

Dan,

[sgt.flippy]

I first thought the same thing, it was too severe, so I tried to look at real cars racing and driving, and I noticed it isn't that far away from the real thing. I don't know about pressure and stuff, but I notice the tyre "falls of" the rim in real life too sometimes.

[Scawen]

Default is 31.9, Race_S is 31.2 in fact.

So you're about 2 psi below recommended pressure. Also we can't see from your screenshot what you are doing, is the front right wheel heavily loaded, do you have a stiff front anti roll bar, etc.

I don't think the deflection is far from correct, I see extreme tyre deflection on road tests on Top Gear, Fifth Gear, etc. And in real life when I've watched road cars take a corner very hard, same thing.

F1 tyres do some big deflection as well, watch the GP this weekend, I seem to remember the Italians like to do a lot of slowmotion shots and you see the tyres moving all over the place on the chicanes.

[viper-gt]

Greetings scawen:thumb:


I've noticed that the logo's don't deform with the tyres, not much a bug, but it's there:) I sometimes use a custom view that's just outside the drivers side window, where you can see the dash still(guages etc) and the font wheel, that's where I most noticed it, as you are basically looking at the tyre in a profile view.

[Funnybear]

S'true. Tyres deform a hell of a lot IRL. F1 tyres are all over the shop. When I saw the screen shots for the patch buildup I was actually suprised to see tyre deformation there at all. I think the fact that we have it all is a testament to Scawens programming and considerations. I think the tyre modelling (Unless you want to get into minutia) is actually quite adequate for LFS's needs atm . . .

[Tweaker]

I think the amount of deformation is ok, but the profile of the LFS tires is rather round. Most tires that you see being nearly pulled off the rim are low profile tires and ones that have a 'sharp' edge where the sidewall and tread meet.

I know one car for example that has those kinds of tires and ALWAYS has this tire deformation, the EVO VII, and Skyline GTR too actually.

[Tweaker]

So basically what I am saying is, the tire doesn't have a long and broad round curve when the tire flexes, it needs to have a FLAT contact patch on the ground as if it were gripping, but also be pulling to make a sideways deformation.

EDIT: Well these aren't flexing much
http://members.cox.net/jeggert4/images/Focus_chase_2.jpg
http://www.tyrolsport.com/midohiopics/MKS_5830.JPG
http://img.photobucket.com/albums/v317/6cylVWguy/Hyperfest/IMG_0287.jpg
http://img.photobucket.com/albums/v317/6cylVWguy/Hyperfest/IMG_0510.jpg

Cannot find a great picture, but see here:

[danowat]

Fair play, if the general concensus is the deflection is correct, then I am happy with that, my ARB is quite stiff, I am pulling maybe 1.4G around the corners, they are high speed corners, but it just looks odd, the tyres look like blu-tac.

I run 40 profile tyres on my road car, and if they deformed any where near this much i'd be on the rims :thumb:, mind you they are reinforced sidewall tyres.

Will this new tyre model put an end to the setups with extremely low tyre pressures?, if I am getting this much deformation with 30psi, I would how it would work with some of the 16psi setups I have seen

Dan,

[JeeP]

i remember some footage of a f1 michelin tire that just moves left /right all the time on the rim while its in the air, or under heavy load!!

maybe you can see it in the GP this weekend !

adios JeeP

[Madman_CZ]

heres a little vid of tyres deforming, its not very gd quality but you can make out especially on the front wheels of the two white cars LINK (http://uk.wrs.yahoo.com/_ylt=A9ibyj6rEkpExz0B9uB1BQx./SIG=13268mvk2/EXP=1145791531/**http%3a//gtr.com.au/Videos/Japanese%2520Import%2520Cornering%2520Comparison.m peg)

[KTy]

So basically what I am saying is, the tire doesn't have a long and broad round curve when the tire flexes, it needs to have a FLAT contact patch on the ground as if it were gripping, but also be pulling to make a sideways deformation.

EDIT: Well these aren't flexing much
http://members.cox.net/jeggert4/images/Focus_chase_2.jpg
http://www.tyrolsport.com/midohiopics/MKS_5830.JPG
http://img.photobucket.com/albums/v317/6cylVWguy/Hyperfest/IMG_0287.jpg
http://img.photobucket.com/albums/v317/6cylVWguy/Hyperfest/IMG_0510.jpg

Cannot find a great picture, but see here:

I couldn't find any pictures, but something like 10 years ago when the Citroen Xantia with active suspension came out, they were a lot of picture of the car cornering like mad with no roll at all; You could see tires almost jumping out of the rims, *very* impressive !:scratchch

[Honey]

my impression is that for slick tires it seemsquite real but not for road normal/super tires.

i mean, i suppose normal tires are on "standard" rims and road super on a bit bigger rims and what it feels very wrong to me is the relation pressure/grip, in real life when "road normal" tires have low pressure they deform a lot, but still much less than in lfs (visually speaking), in RL when tire pressure is under the optimal, grip is much less, while in lfs grip is MUCH MORE! so people tend to use low pressure tires...my first impressions are that with new patch slick tires seems much more realistic (but i dont have much experience with RL slicks), but road tires fells much worse, but the point to me is only due to pressure/grip relation.

using F9 it clearly shows that even with exaggerated negative cambers we are always driving on sidewalls if we dont put extremely high pressures, so im pretty sure something has to be tuned.

i also think that the pressure/grip was wrong in patch Q but never showed up so clearly because of lesser realistic tire simulation, now that tire simulation is much improved, it feels much evident IMO.

[Ramses]

On school we used to have Michelin days where they would give information about their tires. They showed footage from a camera mounted below a 205/16 in action. It looked pritty much like those screenshots above. It looked just like a giant hand was constantly trying to pop the heel over the rim. It took us a while to actually accept that that was a tubeless tire :)

But I don't know if modernday tires still bend that much.

[Honey]

On school we used to have Michelin days where they would give information about their tires. They showed footage from a camera mounted below a 205/16 in action. It looked pritty much like those screenshots above. It looked just like a giant hand was constantly trying to pop the heel over the rim. It took us a while to actually accept that that was a tubeless tire :)

But I don't know if modernday tires still bend that much.

we are not talkin only about graphic effect BUT phisic effect: if u try lapping with F9 info u see that while cornering the wheight is all on the very edge of the tire while the 66% of tire surface is "lifting" from tarmac...and this cannot be right/real

[col]

I think the reason some people have a problem with the deformation in LFS is because visually it 'doesn't look quite right'.

I think that this is because under severe deformation, the tyres in LFS don't move laterally on the rim (at least visually they don't), whereas in real life they would, this means that they look more 'stretched' than in real life.

I couldn't care less about this - it's not noticable when racing, and I doubt that it has any impact on the accuracy of the algorithm in terms of feel. Just be aware that it makes things look a little odd in close-up stills of the effect.

cheers

col.

[KiDCoDEa]

those are road tyres under gp conditions.
how often do u see that?

people tend to forget they are using normal everyday cars with normal everyday tyres on grandprix circuits, causing huge Gs...


lfs will also improve in future where diferent brands will cause dif tyre natures...

[ajp71]

Rememember the cars in LFS are being setup with full adjustable full race suspension to be very stiff. Add to that the lack of body flex simulation and low tire pressures and stupid amounts of tire deformations are bound to happen until the sets get adjusted to the new physics.

[Honey]

those are road tyres under gp conditions.
how often do u see that?

people tend to forget they are using normal everyday cars with normal everyday tyres on grandprix circuits, causing huge Gs...


lfs will also improve in future where diferent brands will cause dif tyre natures...

infact i consider because i drive my car (xfg like) at its very grip edge even while braking and even while cornering, so while i specified i do not have experience with slicks and not said it about road tires, i tought it was clear i think to be enoughly objective and see if someone else have the same feelings.
a firend of mine with a similar car but with slightly better tires (17 inches rims and litle wider tires), has very little deformation.

as i said my point is not merely on graphical effect wich is much less important, but quite on phisic effect. as tweaker said, the flat part of tire is "hardly" deforming in RL but on lfs is the opposite...anyway, screenshots previously posted show powerful cars at very limit race conditions and u can see yourself the amount of deformation.

[colcob]

I think everybody should just stop anally examining every little bit of physics/simulation and just go and bloody well race. Have fun, its this kind of constant second guessing and speculation about whether something is right or not that is sucking the joy out of the sim racing community.

No offense to you personally Dan :)

[Honey]

Rememember the cars in LFS are being setup with full adjustable full race suspension to be very stiff. Add to that the lack of body flex simulation and low tire pressures and stupid amounts of tire deformations are bound to happen until the sets get adjusted to the new physics.
well before starting to speak i've done some tests changing settings...and it seems i was quite in touch with the new patch since with xfg i've managed to be 1 or 2 seconds fater than other online and even more fast offline.

also i have more than enough phisic knowledge to know that what F9 shows you with road tires is very far from reality.

you talk as you would have tested lot, but you clearly didn't even a little, please do some test to see what im talking about

[danowat]

I never said whats right and whats wrong, just wanted some opinion on it TBH :)

I have been racing, a lot, and I was analizing why the FXO didnt lap aswell as it did, and why the other cars were better, now I have made a list of the car changes I can see why.

Sorry for over-analizing it, its just it feels so new and alien ATM.

Dan,

[JTbo]

Tires bending under wheel, this happens with road tires, does not happen so much with skicks as those are more rigid/stronger.

When I took my car first time to track I had just normal road pressures and my alloys got scratched, that is how much rubbers bend when taking those corners hard enough.

http://www.janiervast.com/gallery/d/61-2/IMG_3378.JPG (http://www.janiervast.com/gallery/v/volvo/syksy/renkaat/IMG_3378.JPG.html)
You can see here how edge of tire has been melting even I had that 3 bar pressure! 185/60-14 is size...
Also sidwalls have always shown some scrubbing against tarmac.

Scawen has made this special detail very close to perfection, imo.

[Scoop]

it's all about presure presure presure, those pic that Tweak posted are normal road cars so i'm expecting them to have normal road presure, and that's high compared to what we use in game for our race set, that's why the tyres flex a lot, i wouldn't recomend it but u could go and inflate the tyres on youre car to the presure u have them (say on the FXO) in game and see if they flex as much
(AGAIN I WOULDN'T RECOMEND IT, i don't want anyone coming here saying Scoop i wrecked my car)

[Breizh]

Anyone remember that red Porsche slomo vid, riding a curb?
I have it, if anyone can host it. It's 35 megs.

[JTbo]

it's all about presure presure presure, those pic that Tweak posted are normal road cars so i'm expecting them to have normal road presure, and that's high compared to what we use in game for our race set, that's why the tyres flex a lot, i wouldn't recomend it but u could go and inflate the tyres on youre car to the presure u have them (say on the FXO) in game and see if they flex as much
(AGAIN I WOULDN'T RECOMEND IT, i don't want anyone coming here saying Scoop i wrecked my car)

Pressures of tires depends lot from what kind of tires are. Normal pressure to my tires is 2bar, if you put 3bar to lfs tires it flexes less than my tires in reallife...

[cannonfodder]

In the BF1 with wheels only view and the default setup, there's visible deformation on high speed corners like after the long straight on AS Nat. Is the amount about right or should the pressures be higher?

[wheel4hummer]

http://www.gom.com/En/Applications/Deformation/lsc/tire.html

we also should have body deformation
http://www.gom.com/En/Applications/Deformation/lsc/car.html

[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.

PS again some posts above there are some RL screenshots of cars racing that shows how much tire deforms, if you don't believe me that watch those screenshots to face the reality: the tire deformation IS wrong!

[ElfjeTwaalfje]

First the images (Google'd):

Normal road cars (huge deformation)
http://toyotaownersclub.com/forums/lofiversion/index.php/t47764.html
MRT type car (no deformation)
http://sae.secsme.org.au/home.htm
http://fsae.utoronto.ca/2002/videopr.html
Rally cars (some deformation)
http://www.2.justbajan.com/cars/motorsports/2004/042804_mcbiral/2.htm
http://www.2.justbajan.com/cars/motorsports/2004/042804_mcbiral/4.htm
F1 (slow corner @ Sepang, no deformation)
http://img39.photobucket.com/albums/v119/reversemode/F1-Sepang/malaysia_1st_corner.jpg
Some more F1 (little deformation)
http://autosport.sbs.nl/modules/sbsautosport_home/galleryframe.php?site=sbsautosport&section=gallery&image=2526
http://autosport.sbs.nl/modules/sbsautosport_home/galleryframe.php?site=sbsautosport&section=gallery&image=2484
http://autosport.sbs.nl/modules/sbsautosport_home/galleryframe.php?site=sbsautosport&section=gallery&image=2536

This should be enough. Note that F1 tyres are very flexy and balloonish and are an integral part of the suspension.

All in all I would say, to many variables at play here to say LFS is right or wrong. And frankly I don't look at my tyres touching the road when driving. I only want a good road feel when I am driving.:eclipsee_

[Honey]

First the images (Google'd):

Normal road cars (huge deformation)
http://toyotaownersclub.com/forums/lofiversion/index.php/t47764.html
MRT type car (no deformation)
http://sae.secsme.org.au/home.htm
http://fsae.utoronto.ca/2002/videopr.html
Rally cars (some deformation)
http://www.2.justbajan.com/cars/motorsports/2004/042804_mcbiral/2.htm
http://www.2.justbajan.com/cars/motorsports/2004/042804_mcbiral/4.htm
F1 (slow corner @ Sepang, no deformation)
http://img39.photobucket.com/albums/v119/reversemode/F1-Sepang/malaysia_1st_corner.jpg
Some more F1 (little deformation)
http://autosport.sbs.nl/modules/sbsautosport_home/galleryframe.php?site=sbsautosport&section=gallery&image=2526
http://autosport.sbs.nl/modules/sbsautosport_home/galleryframe.php?site=sbsautosport&section=gallery&image=2484
http://autosport.sbs.nl/modules/sbsautosport_home/galleryframe.php?site=sbsautosport&section=gallery&image=2536

This should be enough. Note that F1 tyres are very flexy and balloonish and are an integral part of the suspension.

All in all I would say, to many variables at play here to say LFS is right or wrong. And frankly I don't look at my tyres touching the road when driving. I only want a good road feel when I am driving.:eclipsee_

so "except" the first 2 screenshots you are cleary saying that lfs deformation is way too exaggerated...

also in the first 2 screenshots, tires are smaller than xfg and still they deform way much less than lfs -> the xfg at slow speed deform much more than the extreme situation of the citroen in the screenshot.

what everyone do not want to hear is teh artifacts:
1 - lfs tires do not deform by "displacement", but they "stretch" reducing the contact surface...that's impossible! on the contrary in real life in very infinitesimal amount the tire surface tend to "enlarge"

2 - in lfs tires the central part seems to have some sort of vacuum having the less pressure, meaning that the center part of the tire lift from road having some misterious force that attracts toward the rims...obviously this is absurd

3 - lfs deformation (eg xfg) at slow speeds (like driving in real life into traffic) is much more than the most extreme situation in the real life (eg the citroen in the previous post)...i don't know you, but when i drive at 50kmh into traffic i don't see any deformation at all...

i stop talking other things, because if you people cannot see those 3 evident absurd things, you are clearly blinded by the pleasure of handling formula cars and gtr like if they was 900cc/50bhp cars...

[Scawen]

2 - in lfs tires the central part seems to have some sort of vacuum having the less pressure, meaning that the center part of the tire lift from road having some misterious force that attracts toward the rims...obviously this is absurdWhat's this? :shrug:

3 - lfs deformation (eg xfg) at slow speeds (like driving in real life into traffic) is much more than the most extreme situation in the real life (eg the citroen in the previous post)...i don't know you, but when i drive at 50kmh into traffic i don't see any deformation at all...You hang out of your car looking at the tyres, while cornering at the limit of grip, at around 1g? You are very brave! :D But that may be a bit dangerous.

[Honey]

What's this? :shrug:

You hang out of your car looking at the tyres, while cornering at the limit of grip, at around 1g? You are very brave! :D But that may be a bit dangerous.
the first point is: with F9 info even at slow speeds (50kmh eg) the center pressure is the less, while the gradient should not change sign, wich means that if at the outer side there is the maximum pressure, in the center it should be between the outer and the inners pressure...how it is now, it means that the central part of tire is "lifting from tarmac" and the tire is bending inside toward the rim (only the central part)

the second point i mean: at 50kmh into traffic tires "are not deforming", while in lfs they are much

[Honey]

just to be clear i dont want to say this patch is ugly, ideed at most is a huge improvement, but to me: tire deformation on road tires and pressure/grip relationship are a bit too wrong and may feel thing lot bad, i hope that after the "bf1 fever" more people speking english better than me, can do the same tests and give more feedback.

edit: PS scawen from your reply you clearly didn't read what i wrote, reading again i think i explained clearly what i meant, but i could be wrong obviously :D

[Vain]

2 - in lfs tires the central part seems to have some sort of vacuum having the less pressure, meaning that the center part of the tire lift from road having some misterious force that attracts toward the rims...obviously this is absurdIn driving school I was told that this is the reason why you shouldn't use too low pressures on your tyres. The outer sides will get used up too fast because the inner part slightly lifts from the tarmac.
So you're driving under-pressured tyres and that is propably the reason why you also see big tyre deformation.

Vain

[Honey]

In driving school I was told that this is the reason why you shouldn't use too low pressures on your tyres. The outer sides will get used up too fast because the inner part slightly lifts from the tarmac.
So you're driving under-pressured tyres and that is propably the reason why you also see big tyre deformation.

Vain
that's because with low pressure, the tire "displace" a lot having to drive only on outer edge...since you "averagly" turn 50% left and 50% right you consume only the both edge of a tire and not the center.

and with low pressure "the center tend to lift" but "the inner part tend more" and that's natural, what it's absurd is center "lifting" more than "inner"

PS i did a lot of semplifications in terms hoping to be more clear, i hope you get it right ;)

EDIT: about low pressure: as i did before i did tests very different settings and at 2.2 bar (the max recommended for an xfg like car) this is still ugly, only at max lfs tire pressure and maximum negative camber things START to be normal

[Funnybear]

If you are using old setup tyre pressures with the new patch physics then I think you will get anomalous readings. With the new 'grip' factor I think you will find that the setups will adjust to a more realistic setting with stiffer suspension, higher tyre pressures and less camber. This will lesson the immeadiate effect of how you see tyre deformation now. Of course a low pressure tyre will defrom to large degrees, it's got nothing to hold it up.

I think a discussion of this nature needs a few more weeks of 'gametime' maturity before exhaustive critism can take place effectivly.

[Honey]

If you are using old setup tyre pressures with the new patch physics then I think you will get anomalous readings. With the new 'grip' factor I think you will find that the setups will adjust to a more realistic setting with stiffer suspension, higher tyre pressures and less camber. This will lesson the immeadiate effect of how you see tyre deformation now. Of course a low pressure tyre will defrom to large degrees, it's got nothing to hold it up.

I think a discussion of this nature needs a few more weeks of 'gametime' maturity before exhaustive critism can take place effectivly.
if you read my posts or even just one of them you will see that i already doen the tests you suggest, how funny that everyone's says i'm wrong but nobody dare to take some test and discuss about the results, moreover none seems to take care of the real screenshots posted above, all real picture show evidently even at the most first view, how the lfs deformation is wrong -> causing huge phisic unrealism.

[varjsa-9]

nobody dare to take some test and discuss about the results

Did. Found nothing funny :D

[Blackout]

Did. Found nothing funny :D

In LFS or with real car? :scratchch

[Stregone]

if you read my posts or even just one of them you will see that i already doen the tests you suggest, how funny that everyone's says i'm wrong but nobody dare to take some test and discuss about the results, moreover none seems to take care of the real screenshots posted above, all real picture show evidently even at the most first view, how the lfs deformation is wrong -> causing huge phisic unrealism.

The thing is, all these pretty pictures do not tell you how much air pressure the tires have, how fast the car is going, how many G's it is pulling, and etc. There just isn't enough information in them to say one way or the other.

[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.

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.

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.

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.

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

[SlamDunk]

Anyone remember that red Porsche slomo vid, riding a curb?
I have it, if anyone can host it. It's 35 megs.
http://www.rapidshare.de

[NotAnIllusion]

http://www.sendspace.com/

I can't use RS ;)

[RevMonkey]

What's this? :shrug:

You hang out of your car looking at the tyres, while cornering at the limit of grip, at around 1g? You are very brave! :D But that may be a bit dangerous.
lmao at the second part ^_^

hehe that was funny :D

[deggis]

Here's the Porsche clip: http://rapidshare.de/files/18017543/tyre.avi.html (didn't upload this again, just had the link on my memo.txt :D)

And some "comparison"... don't know what pressures the BF1 had because it was a wr hotlap from lfsworld.net. Though the rims were still "misplaced", they just don't show up in the screens.

[NotAnIllusion]

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.
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 :p) 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

[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

[qrac]

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..

[Honey]

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

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

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

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

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

[Honey]

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 :p) 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.

[Ball Bearing Turbo]

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.


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.

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.

[Shotglass]

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

[Ball Bearing Turbo]

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.

[KiDCoDEa]

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...

[Cue-Ball]

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.

[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

[Honey]

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... ;)

[Shotglass]

a girl like me

big mistake posting that info openly round here

[Honey]

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

[Honey]

___ ___
---___ ___---

A B

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)

[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

[Shotglass]

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 ?

[KiDCoDEa]

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...

[Shotglass]

lack of balloning effect per pressure?

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

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

[KiDCoDEa]

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.

[Honey]

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...)

[atledreier]

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...

[Honey]

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 :shy:

[KiDCoDEa]

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 :)

[Honey]

...
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

[KiDCoDEa]

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 :) .

[KiDCoDEa]

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

no u didnt. since the thread started.

[Shotglass]

your considerations about shift-l data and guesses, seem to confirm a graphical thing: the tire seems not to displace, but rather stretch...

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

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...)

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

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

dont forget that with high neg camber the insides heat up considerably under acell and braking

but tbh i dont see modern tyres turning to jelly bags at normal range pressures.

imho the effect of pressure on deformation under centrifugal forces should be rather slim

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

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

shift L is a very simplified schematic representation. it is not the whole story of whats happening.

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

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 :) .

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 ?

[letdown427]

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.

[Honey]

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
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

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
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

dont forget that with high neg camber the insides heat up considerably under acell and braking
yes, i considered, but i think i should repeat tests being sure to avoid these effects to have a more objective result

imho the effect of pressure on deformation under centrifugal forces should be rather slim
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

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
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

[NotAnIllusion]

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)

http://img206.imageshack.us/img206/5523/livecamber6ba.th.jpg (http://img206.imageshack.us/my.php?image=livecamber6ba.jpg)

[letdown427]

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


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.

[Honey]

the images in this page http://www.rsracing.com/tech-tire.htm
show why i think the current lfs model is very wrong

[Honey]

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.
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

[Honey]

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)

http://img206.imageshack.us/img206/5523/livecamber6ba.th.jpg (http://img206.imageshack.us/my.php?image=livecamber6ba.jpg)

in real life it's definately not possible...and that's all the dicussion about

[NotAnIllusion]

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 :p Thanks ;)

[Shotglass]

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

[Ball Bearing Turbo]

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

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.

[Honey]

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
think to your exam is much more important :thumb:

btw with the previous images at linked page i meant that either way lfs model is incorrect

[Darkone55]

First the images (Google'd):
F1 (slow corner @ Sepang, no deformation)
http://img39.photobucket.com/albums/v119/reversemode/F1-Sepang/malaysia_1st_corner.jpg
Some more F1 (little deformation)
http://autosport.sbs.nl/modules/sbsautosport_home/galleryframe.php?site=sbsautosport&section=gallery&image=2526
http://autosport.sbs.nl/modules/sbsautosport_home/galleryframe.php?site=sbsautosport&section=gallery&image=2484
http://autosport.sbs.nl/modules/sbsautosport_home/galleryframe.php?site=sbsautosport&section=gallery&image=2536


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.

[ElfjeTwaalfje]

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.

[Cue-Ball]

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.Luckily, we're not using visual observations, but instead are relying on LFS's built-in tire analyzing tools and data.
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.
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.

[Tomi]

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.

[letdown427]

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.

[ElfjeTwaalfje]

Cue-Ball,
Quote:
"However; that doesn't mean that it shouldn't be looked at and addressed, if possible."
Unquote

Agree and point taken.

[Honey]

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.
sorry i wanted to reply but forgot... :shy:

pressure is uniform, F9 readings should be the mechanical load against the tarmac

[tristancliffe]

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?

[Honey]

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?
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 ;) :D

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

[letdown427]

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.

[tristancliffe]

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...

[letdown427]

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...

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 :scratchch

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 :x

[Honey]

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.
maybe now i understand your whole question...well the F9 readings i think are the contact area of the tire, in the entire discussion we used those readings to see how the weight (load) of the car distibutes over the tire regions

[Honey]

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...

in phisics by definition pressure is only for gases/fluids it has the metric of force/area but its measured in pascal (and it is defined as "the air pressure at sea level"), for gases has no meaning talking about force, only pressure.
about your hands you simply apply a "force per area" (that is also not uniform), but that cannot be called pressure by definition

[DEVIL 007]

Hi all,

Flame me if you want after my post but Scawen is just a human after this all GREAT work he made and the only one who work on the game code.
I sometimes dont understand people who say like "it was requested many times but its still not included".
There are other simulation made in past or around the date of LFS and guess how big the development team was and how far the simulation went comparing to LFS...see it?!!
And to be honest there could be programmed thousands of tiny details to the LFS but you would need Super Computer to get decent frame rate.
During the time of LFS development the PC computing power is growing so you can get decent frame rate with every upgrade to the phisic code.

Just see what happend after latest update to the phisic code.The actual frame rate had dropped a bit as some people complained.I guess its for 99percent due to update to the phisic code.

And I understand your pointsabout the issues and missing things but please try to consider more the situation in which is LFS developed.

[Honey]

Hi all,

Flame me if you want after my post but Scawen is just a human after this all GREAT work he made and the only one who work on the game code.
I sometimes dont understand people who say like "it was requested many times but its still not included".
There are other simulation made in past or around the date of LFS and guess how big the development team was and how far the simulation went comparing to LFS...see it?!!
And to be honest there could be programmed thousands of tiny details to the LFS but you would need Super Computer to get decent frame rate.
During the time of LFS development the PC computing power is growing so you can get decent frame rate with every upgrade to the phisic code.

Just see what happend after latest update to the phisic code.The actual frame rate had dropped a bit as some people complained.I guess its for 99percent due to update to the phisic code.

And I understand your pointsabout the issues and missing things but please try to consider more the situation in which is LFS developed.
hi, oviously we all thank scawen, eric and victor for their daily hard work that had and will give us much fun.
scawen told months ago that this patch would have fixed tires and aerodynamic...period! we are all happy for the big surprise of a new real car (BF1) wich is more that he promised...i would love much things inside lfs, but i didn't blame the devs for not including anything, since the announcement was clear -> tire and aero.

what we are trying to understand and put attention on, is that even if (probably because of michelin data) slick tires seems much more realistic (even if it's hard for me to judge since i'm not a slick expert), something with road tires has gone too much unrealistic and smaller cars like xfg make it really evident.

we are not complaining, asking or pretending anything...we are only try to find out the most effective and clear feedback as possible to see if:
1 - there is effectively a big issue in the new tire phisic (i think it's quite evident)
2 - what is actually wrong (to me is only wrong some paramenters of some phisic functions)
3 - summarize and clarify things as much as possible so that in the future if and when the devs think that this have to be fixed they have enough information to know where to start diggin into...

if you read the thread more carefully you will see that we are not blaming devs for anything (except for scawen's bad sarchams :D ), only trying to do the previously mentioned things.

cheers ;)

[KiDCoDEa]

1 - there is effectively a big issue in the new tire phisic (i think it's quite evident

after 4 pages of your rants, im still waiting, in proper english and in one sentence if you dont mind, for you to tell us all what the problem is.

due to my own male limitations please consider in your reply that left is left and that right is right.

anxiously waiting.

[tristancliffe]

No left is up and right is rear left.

[letdown427]

I was just hoping to continue the discussion with a little input as regards a possible explanation for the seemingly odd results Honey is seeing.

Personally, I'm extremely happy with the game, the patch, and everything about it, and I don't feel it's my place to criticise the game's code, as I for one could not hope to reproduce it or create something better.

On that note, I'm out of this discussion, hope you reach a conclusion! :)

[DEVIL 007]

something with road tires has gone too much unrealistic and smaller cars like xfg make it really evident.

1 - there is effectively a big issue in the new tire phisic (i think it's quite evident)
3 - summarize and clarify things as much as possible so that in the future if and when the devs think that this have to be fixed they have enough information to know where to start diggin into...

if you read the thread more carefully you will see that we are not blaming devs for anything (except for scawen's bad sarchams :D ), only trying to do the previously mentioned things.

cheers ;)

I am just really curious what is so unrealistic.After so many years spend with LFS since very early 0.1demo the handling of XFG(most closest to the real car everybody use) I feel it so realistic in most situations.Its really like I was feeling that I am actually driving something...some mass,I feel the tyres.


Dont get it wrong but actually how much driving experiencies you have?

1-you dont see much into the system of the code so you might reading somne values wrong.I dont say the issue doesnt have to be there.
3-there is always good to get a point for devs.I made the same too but they are also smart people enough.

I didnt not say that anybody was flaming devs but I noticed already by some people even in this thread they said "It was asked and its still not there" .You just cant snap with your fingers and its done.everything need a time.

[Honey]

after 4 pages of your rants, im still waiting, in proper english and in one sentence if you dont mind, for you to tell us all what the problem is.

due to my own male limitations please consider in your reply that left is left and that right is right.

anxiously waiting.
i'm not ranting, i'm always calm ;)

left and right were referred to the sketches in the post were "left" and "right" were written, otherwise i've referred to outer or inner part of the tire while cornering, that seemed clear ofr everyone except you, i'm sorry if i cannot halde the english language to explain you better, if you have some hint...you're welcome!

the issue is:

1-a car with road tires (xfg more than others) is always cornering on sidewalls no matter how much pressure you inflate and/or how much negative camber you set

2-a car with road tires (xfg more than others) when cornering tend to lift the central and the inner part of the tire, having the central part lift much more even than the inner part (see my ugly "sketches" on a previous post) and that is "against any phisic law"

[Shotglass]

kid could you just for once stop flying in other peoples faces just because they critisize lfs ... be my guest and have a go at the guy who started the fubar thread but stop it with people who try to point out flaws and make constructive critisism instead of bashing the sim
and just in case ... this is not my male protection mode your protective behaviour towards lfs annoys me since quite a while

back on topic

so an exam and a bit of thinking about tyres later ive come to believe that my idea of the contact patch folding a little might be correct and that the same thing happens in real life too to some extend not as much as in lfs though (might point to too little stiffness in the contact patch of the tyres)
take this pic for example: http://www.liveforspeed.net/page_images/aprilupdate/tires1.jpg looks like the outside sidewall deforms more than the inside which would mean that the contact patch has to either squeeze or fold

looking at pics of tyres deforming in lfs (eg this one: http://www.liveforspeed.net/page_images/aprilupdate/tires4.jpg ) one thing that strikes me as odd is that the sidewalls seem to deform in two ways that arent necessarily correct:
1) they appear to tilt to the side instead of deforming and bulging a little which might be caused by the sidewall being modelled as a single straight line (ie two sample points) the effect of which could be that the sidewall is generally too stiff
2) the sidewalls appear to strech out a lot which imho is incorrect or at least too much for rubber with kevlar inlays

[colcob]

in phisics by definition pressure is only for gases/fluids it has the metric of force/area but its measured in pascal (and it is defined as "the air pressure at sea level"), for gases has no meaning talking about force, only pressure.
about your hands you simply apply a "force per area" (that is also not uniform), but that cannot be called pressure by definition

I'm sorry, I'm not sure what your physics background is, but pressure is simply a force divided by the area over which it is applied. There is nothing in physics which states it applied only to gases and fluids, that is simply nonsense.

http://en.wikipedia.org/wiki/Pressure have a read here to get yourself up to speed.

Also, just to be really anal, a pascal is not atmospheric pressure at sea level, that is a Bar*. A pascal is an SI unit and is therefore 1N/m2. Which is actually really quite a small unit, hence a typical tyre pressure is measured in hundreds of kPa.

While I welcome anyone getting involved in physics debates, I would recommend doing a bit of basic checking with google and wikipedia before attempting to state facts, just to stop yourself looking a bit silly.

*To be even more anal, technically an Atmosphere is atmospheric pressure, but a Bar is a convenient rounding to 100,000 pa, and is only a bit off an Atmosphere.

[danowat]

I think you might be on to something there Shotglass, it does indeed seem that it could be the sidewall stretching.

I made a video of the FXO tyre deformation here > http://video.google.com/videoplay?docid=5501806063980312193&q=Tyre+deformation+in+Live+for+speed&pl=true

Google video made the quality poor, but you can see the deformation "in action".

Dan,

[tristancliffe]

With a 'standard atmosphere' being 101325Pa, or 1.01325Bar ;)

Shotglass - I agree the sidewalls shouldn't stretch so much, though the actual deformation (bending) appears to be about right. Perhaps it's relatively simple to change the code so that the amount of bend remains the same but the stretch is reduced to, say, 5% which is closer to what a tyre would actually acheive. As to whether the rubber folds or squashes on the contact patch I'd tend to have said squashing occurs. But honeys pics of the center of the contact patch having less pressure on them (from the road) may mean that Scawen has indeed modelled the folding/curvature that would occur.

[Galthar]

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?




force of ther road pushing on the outside for sure

[Honey]

I'm sorry, I'm not sure what your physics background is, but pressure is simply a force divided by the area over which it is applied. There is nothing in physics which states it applied only to gases and fluids, that is simply nonsense.

http://en.wikipedia.org/wiki/Pressure have a read here to get yourself up to speed.

Also, just to be really anal, a pascal is not atmospheric pressure at sea level, that is a Bar*. A pascal is an SI unit and is therefore 1N/m2. Which is actually really quite a small unit, hence a typical tyre pressure is measured in hundreds of kPa.

While I welcome anyone getting involved in physics debates, I would recommend doing a bit of basic checking with google and wikipedia before attempting to state facts, just to stop yourself looking a bit silly.

*To be even more anal, technically an Atmosphere is atmospheric pressure, but a Bar is a convenient rounding to 100,000 pa, and is only a bit off an Atmosphere.
wikipedia is wrong, pressure is a measurement only for gasses/fuilds (in phisics), it may be popular to call a force/area pressure but this by any meaning wrong, as i said pascals have intrinsecally the "metric" (dunno the correct english word for this) of a force per area, but by definition it will never really counted like that (except for special purposes) but rather by pascals which is by definition a fraction of bar wich is by definition the air pressure at sea level (as i said in a previous post).
as you asked: i'm an engineer and i worked bla, bla...that realy doesn't matter since there are enginners, phisicist, etc. that sometimes are damn wrong etc. you don't have to believe me that wikipedia is wrong, but if you have a chance to open a real phisic book you know (after studying a bit :) ) what pressure is

[tristancliffe]

LOL

I think there's a good chance you, being one of the few people to think pressure only applied to fluids, is wrong. Perhaps you should read up on it ;)

[Honey]

kid could you just for once stop flying in other peoples faces just because they critisize lfs ... be my guest and have a go at the guy who started the fubar thread but stop it with people who try to point out flaws and make constructive critisism instead of bashing the sim
and just in case ... this is not my male protection mode your protective behaviour towards lfs annoys me since quite a while

back on topic

so an exam and a bit of thinking about tyres later ive come to believe that my idea of the contact patch folding a little might be correct and that the same thing happens in real life too to some extend not as much as in lfs though (might point to too little stiffness in the contact patch of the tyres)
take this pic for example: http://www.liveforspeed.net/page_images/aprilupdate/tires1.jpg looks like the outside sidewall deforms more than the inside which would mean that the contact patch has to either squeeze or fold

looking at pics of tyres deforming in lfs (eg this one: http://www.liveforspeed.net/page_images/aprilupdate/tires4.jpg ) one thing that strikes me as odd is that the sidewalls seem to deform in two ways that arent necessarily correct:
1) they appear to tilt to the side instead of deforming and bulging a little which might be caused by the sidewall being modelled as a single straight line (ie two sample points) the effect of which could be that the sidewall is generally too stiff
2) the sidewalls appear to strech out a lot which imho is incorrect or at least too much for rubber with kevlar inlays
once more you are proving to know how to dig into lfs phisics...

as i wanted to "prove" with the link i posted in a previous post (http://www.rsracing.com/tech-tire.htm) sidewall must first of all displace and the center cannot lift more than the inner part, as you clearly noted the source of the problem may be even only the sidewall streching, maybe devs used the real data from slick to simulate that, but if so it is very wrong imho.
imho for road tires the sidewall streching effect should be very negligible and could be even taken out from the lfs equations

[letdown427]

may mean that Scawen has indeed modelled the folding/curvature that would occur.

Or that the force applied to the sidewall and flat contact patch isn't so vastly different, and that because there areas are different, that's why the pressure appears to have dropped in the center.

I know I said I was leaving, meh, I returned.

[Shotglass]

...

sry but your wrong there ... pressure is a variable in thermodynamics and while area loads in mechanics are of the same dimension (N/m^2) theyre not called pressure in analy correct physics semantics
also evidently clear as area loads arent measured in the dimension Pa but in N/m^2

I made a video of the FXO tyre deformation here > http://video.google.com/videoplay?docid=5501806063980312193&q=Tyre+deformation+in+Live+for+speed&pl=true

is that an fxo or an fxr ?

Shotglass - I agree the sidewalls shouldn't stretch so much, though the actual deformation (bending) appears to be about right.

not so sure about that to me it looks a lot like they just tilt instead of bending which assuming that the sidewalls are indeed modeled with 2 points (one at the metal and one at the sidewall/contact patch transition) is the effect that model would achieve but also means that it wont be too easy for scawen to change that and that any significant change should cause more cpu load

As to whether the rubber folds or squashes on the contact patch I'd tend to have said squashing occurs.

have you got any pics of how exactly the layers of kevlar and metal are put into a radial tyre ? i cant seem to find anything conclusive

But honeys pics of the center of the contact patch having less pressure on them (from the road) may mean that Scawen has indeed modelled the folding/curvature that would occur.

except the effect appears to be a tad too extreme at the moment

[Honey]

LOL

I think there's a good chance you, being one of the few people to think pressure only applied to fluids, is wrong. Perhaps you should read up on it ;)
there is nobody that can pass the first semester of enginering caliming that...i assure you, if you would have studied, you would know what is the conceptual difference, i wonder why every tech article uses pascal instead of N/m2 when talking about gases/fluids and instead uses N/m2 when talkin baout solids in place of pascals...according to you that must be really an amazing coincidence.
please don't get me wrong but a definition is a definition and have a reason behind it

[Shotglass]

there is nobody that can pass the first semester of enginering caliming that...i assure you, if you would have studied, you would know what is the conceptual difference

whoah easy there we dont want this to turn ugly ... afaik tristan studies mechanical engineering ... struck me as odd too that he doesnt know the difference but not reason to have a go at him ... just let it slide that he put that lol there

[KiDCoDEa]

kid could you just for once stop flying in other peoples faces just because they critisize lfs ... be my guest and have a go at the guy who started the fubar thread but stop it with people who try to point out flaws and make constructive critisism instead of bashing the sim
and just in case ... this is not my male protection mode your protective behaviour towards lfs annoys me since quite a while

so does your nordic imperial nun moralism and stupid moronic pedantic behaviour towards others and u never saw me interrupt your forum wisdom uberalles conversations to review your pitful display of common sense. i stick to ideas, maybe u should do the same.

[bw_krupp]

I only read the first page. All I can say is I have had a normal tire at normal pressure come off the rim in real life after some...interesting...cornering. And if you kick my car (which weighs less than 1700 lbs), you can see some massive deformation standing still. I don't think LFS is severe in the least.

[Shotglass]

so does your nordic imperial nun moralism and stupid moronic pedantic behaviour towards others and u never saw me interrupt your forum wisdom uberalles conversations to review your pitful display of common sense. i stick to ideas, maybe u should do the same.

pardon ?
i assume youre refering to the whole nk crack incident but im not sure

[Honey]

whoah easy there we dont want this to turn ugly ... afaik tristan studies mechanical engineering ... struck me as odd too that he doesnt know the difference but not reason to have a go at him ... just let it slide that he put that lol there
yeah there are few posts for wich the better answer is "LOL"...and i say all

tristan is sympathic anyway, we cannot say that for anyone :D

[tristancliffe]

Perhaps if you get right into the nitty gritty details pressure isn't applicable for mechanics, but you're talking a level of semantics if you ask me. I have always and will always use pressure to discuss force over area in fluids and solids. So do the rest of the world. Unless someone can give me a compelling reason to change, I'll stick with my original remark of LOL :D

Sympathic? Not sure if that's an insult or a compliment, so I'll resort to nodding and smiling :) :nod:

[Shotglass]

So do the rest of the world. Unless someone can give me a compelling reason to change, I'll stick with my original remark of LOL :D

how about just that theres usually a good reason to distinguish 2 variables that mathematically have the same dimension (which i dont know in the case of pressure but im sure there is one)
take watt for example ... W and VA generally are two completely different things in electric engineering

[KiDCoDEa]

pardon ?
i assume youre refering to the whole nk crack incident but im not sure

there was no crack [ EDIT ]. proof is dat the thread stayed in kunos forum and nowadays everyone enjoys the whole content free. it was his mistake, and he corrected it, by making freely available what before required a rename and a replay action.
who da [ EDIT ] are u to judge other people actions in realms u obviously dont have a clue.
cracked is your [ EDIT ].
exploited you were when they convinced ya it wouldnt hurt.
understand the difference now, nun?

[ EDIT by Scawen : We have had a lot of reports about this post. No need to use unpleasant language to make your point. ]

[Shotglass]

there was no crack [ EDIT ]. proof is dat the thread stayed in kunos forum and nowadays everyone enjoys the whole content free. it was his mistake, and he corrected it, by making freely available what before required a rename and a replay action.
who da [ EDIT ] are u to judge other people actions in realms u obviously dont have a clue.
cracked is your [ EDIT ].
exploited you were when they convinced ya it wouldnt hurt.
understand the difference now, nun?

i tink ill go with tristans approach and just nod and smile

[Glenn67]

Forget for a moment the force the road is exerting on the tyre and instead think for a moment of the wieght (force) of the car acting through the tyre...

Now as the tyre (a standard steel belted radial on the outside of the turning circle which is under the most forces) is in mid corner with 1g of lateral force being applied it would have some roll over, which would would effectively mean that the outer wall of the tyre would be semi vertical and the inner wall of the tyre would be heavily distorted (ballooned).
Now think how the wieght will be transmitted through the tyre onto the raod... it would be through the air in the tyre and to some extent through the sidewalls of the tyre.
So if some of the wieght is transmitted through the sidewalls of the tyre (forgetting for a moment camber angles excetra and assuming the tyres entire contact patch is flat on the road) would the majority be tranfered through the semi vertical sidewall and not as much through the largely distorted inner sidewall?
And also if the sidewalls do transfer a little of the wieght, wouldnt it stand to reason that there would be slightly less wieght transfer through the centre of the tyre?
We are talking wieght transfer here and not tyre adhesion to the road...

So if those assumptions were correct then the display that you discribe in F9 would be not that far from reality :shrug: With the slicks they have much stiffer side walls so this effect would not be so noticable.

I drive the XFG alot as well and found it handled wierd in the new patch (felt like i was on cross plys), but after working on setups for a few days have now got it to feel quite natural again without resorting to rediculously high or low tyre pressures (I put the initial wierdness down to not being used to feeling tyre deformation and most of the old setups being unsuitable :tilt: )... whenever there is a major physics update it is going to take some weeks for things to pan out so I wouldnt draw too many conclusions too quickly :)

[Vain]

Actually there is no reason to ever talk about a "force", because in real physics there is no "force" as such since the existance of space. This imaginary thing "force" always acts upon an area, which results in pressure. That means actually a magnet creates a pressure on a piece of ferromagnetic metal, a stone creates pressure when you throw it at a wall, etc. We just use the term "force" because it is practical to do so. Just like it is practical to speak about a "point" in mathematics.
End of discussion about the preasure-thing. ;)

About the deformation:
The tyrephysics aren't finished yet and Scawen has propably noted some of our remarks. Let's wait for the next patch.
End of discussion about the tyres. ;)

Shall I solve any more of your problems? Worldpeace? End of starvation? Impregnate your wife?
:D

Vain

[Shotglass]

oh and by the by ... next time you try to have a go at me ... get your facts right:
http://forum.rscnet.org/showpost.php?p=2999762&postcount=5

[tristancliffe]

I'm not married, but if I were you wouldn't be allowed anywhere near her!!!

[Honey]

Sympathic? Not sure if that's an insult or a compliment, so I'll resort to nodding and smiling :) :nod:
compliment! ;) ...meaning that your are a man with sense of humor ;)

i tink ill go with tristans approach and just nod and smile
the best approach surely ;)

[Honey]

Forget for a moment the force the road is exerting on the tyre and instead think for a moment of the wieght (force) of the car acting through the tyre...

Now as the tyre (a standard steel belted radial on the outside of the turning circle which is under the most forces) is in mid corner with 1g of lateral force being applied it would have some roll over, which would would effectively mean that the outer wall of the tyre would be semi vertical and the inner wall of the tyre would be heavily distorted (ballooned).
Now think how the wieght will be transmitted through the tyre onto the raod... it would be through the air in the tyre and to some extent through the sidewalls of the tyre.
So if some of the wieght is transmitted through the sidewalls of the tyre (forgetting for a moment camber angles excetra and assuming the tyres entire contact patch is flat on the road) would the majority be tranfered through the semi vertical sidewall and not as much through the largely distorted inner sidewall?
And also if the sidewalls do transfer a little of the wieght, wouldnt it stand to reason that there would be slightly less wieght transfer through the centre of the tyre?
We are talking wieght transfer here and not tyre adhesion to the road...

So if those assumptions were correct then the display that you discribe in F9 would be not that far from reality :shrug: With the slicks they have much stiffer side walls so this effect would not be so noticable.

I drive the XFG alot as well and found it handled wierd in the new patch (felt like i was on cross plys), but after working on setups for a few days have now got it to feel quite natural again without resorting to rediculously high or low tyre pressures (I put the initial wierdness down to not being used to feeling tyre deformation and most of the old setups being unsuitable :tilt: )... whenever there is a major physics update it is going to take some weeks for things to pan out so I wouldnt draw too many conclusions too quickly :)
in the attached images you will see basically how tires deform. basically even if sidewalls could theoretically "transimt" a huge amount of the weight of the car, then the outer part of the tire may have an extra load, but the inner part must have a "lift" effect and not the contrary

[Funnybear]

Just smile and wave boys, just smile and wave . . . . .

Have we been here somewhere before?

[Glenn67]

in the attached images you will see basically how tires deform. basically even if sidewalls could theoretically "transimt" a huge amount of the weight of the car, then the outer part of the tire may have an extra load, but the inner part must have a "lift" effect and not the contrary

Thats exactly what I was illustrating which fits with the F9 grey force bars that I get when cornering in say the XF GTi.
In reality though I don't think much is tranfered through the sidewalls but would guess that the shape that the tyre takes on would change how the wieght is transfered through the tyre (via the air in the tyre), which would still lead me to believe that more wieght would be transfered through the outer part (almost regardless of camber angle or tyre pressure) as shows up in the F9 view. But thats well beyond my ability to confirm or deny :p I just thought I would throw in my 2 cents is all LOL

To me the tyre deformation doesnt seem all that unrealistic :shrug: I've got a mid size car and I live down a gravel road so my tyres are always dusty :p and when I take corners aggrssively (on tarmac) you can see the bottom 50% of the sidewalls are nice and black and the top 50% are dusty which means I've been driving partially on the sidewalls :shy: and thats no where near the limit :p

[chp101]

Nice glitch. Hopefuly such threads help Scawen make bettah releases :) There are hundreds of such things to test and look for.

Let's talk about what this glitch brings in terms of performance?
Or maybe in reverse, maybe some glitches in performance make it look bad?

Attachment - 900kg UF1000 on continuous 1g turn.. on 2 wheels.

Those two tyres are stretched for sure.. ;^/

[zeugnimod]

You should login with your S2 account, if you post pictures of S2 content to avoid others from thinking you use a crack.

[chp101]

Others should Read EULA 3.1... and send PM if they are so "worried".

So, nothing to say on improved load/traction performance?

[Batterypark]

You should login with your S2 account, if you post pictures of S2 content to avoid others from thinking you use a crack.

One thing I never understood is why all licensed people should use their licensed account for posting on the forum? I, for one, couldn't care less whether people thought I'm using a crack or not. I actually wish there was a way to hide my license status on the forum.

[Ball Bearing Turbo]

I actually wish there was a way to hide my license status on the forum.

Why is that?

[Batterypark]

Why is that?

Because I would want to hide my license status. :scratchch

[Ball Bearing Turbo]

Because I would want to hide my license status. :scratchch

:doh:
Evidently...

But why?

:shrug:

[Honey]

:doh:
Evidently...

But why?

:shrug:
maybe a thing called "privacy", someone may prefer to not show with his license name (at start i used another nick for that, but then i changed my mind) also because there are some people that watch your hotlaps and ranking to decide if you are entitled to talk

[Hyperactive]

I knew it. No hotlaps = no one talks to me :shrug:


:D

[Ball Bearing Turbo]

Shut up

:razz:

[Honey]

Shut up

:razz:
don't give him so much importance: he's slow! ...he's not even worth a smalltalk :razz: :D

[Micha]

I made a small movie about the new tyre deformation: :thumb:

http://www.pimba-racing.de/data/tyre_deformation.wmv

[tristancliffe]

So glad you stopped the song there ;)

[MadCatX]

So glad you stopped the song there ;)
:iagree:

And about that video: good work, i dont know how are tyres doing in real, but it seems to be too real on some bad-made stuff. Point for ScaViEr:)

[Honey]

I made a small movie about the new tyre deformation: :thumb:

http://www.pimba-racing.de/data/tyre_deformation.wmv

as i said i think the lfs deformation for road tires is a bit too much to me, but the real point is not the amount as much HOW...it seems that as soon as the deformation starts, the contact part of the tire seem to fold innerwise making cornering too weird and innatural

[Shotglass]

this is reactiviating a really old thread but ive noticed something weird about the tyre deformation a few days ago

i was test driving matrixis setup on so and when i spun out i noticed that the car was shaking right after i stopped
at first i though the setup is underdamped but if anything its overdamped and futher investigations showed that its actually the tyres

ive attached a short replay to illustrate what im on about (im using the race s setup btw) ... notice how the rims relative position to the body doesnt change much but the rims potition relative to the ground is changing rather a lot and the whole car is shaking

imho the tyre deformation should be damped a lot more than it currently is

[Funnybear]

What tyre pressures where you running?

[-V-Max-]

if you *would be* able to steer that fast irl, you would also have some wobble

[Blackout]

The cars in LFS sometimes do weird things, haven't that replay but I had a shaky car few times. When starting BL gp hotlap in the GTi for example I let the car go down the hill backwards and it did shake very weirdly when front tires went to full lock in slow speed, and did make a screetch sound allso.

[Funnybear]

You do have to take into account that in LFS you can do stuff that a real car just couldn't do. You try and pull have the stunts that you can do in LFS, like reversing and flicking into first at full throttle no clutch, would just break stuff in real life. So if you are on the very edge of the perfomance envelope or pushing certain attributes then you won't get a real life equavalent because you just can't do those things in real life.

You probable do get tyre wobble in real life but it would be at such a frequency that you couldn't feel it through the suspension. Or you just lump that wobble into the whole suspension, chassis, tyre, big lardy arse gestalt.

Just a LFS defence.

[Shotglass]

What tyre pressures where you running?

whatever the race_s setup has for pressure

if you *would be* able to steer that fast irl, you would also have some wobble

try kicking against your rims irl ... the car will wobble a little but it will damp itself a lot faster

[-V-Max-]

try kicking against your rims irl ... the car will wobble a little but it will damp itself a lot faster

That's why I said 'some', I'm currently working at a volvo garage in brussels. And i noticed today that the S60 wobbles when the driver got out of it, I't wasn't the suspension moving ( id lifted a bit )
It's just a bit heavy in LFS because the model Isn't perfect, we knew that :)

[SabersKunk]

http://videosift.com/story.php?id=5073

Different but cool tyre deformation

[SamH]

tbh I think that the tyre wobble in LFS is probably overgrown a little because there isn't flex elsewhere in the LFS model, that a real car has. For the model's behaviour to be as realistic as it *is* when driving, but with completely rigid drivetrain etc (which is not true to life), the tyres carry all of the flex modelled in LFS. For example, in real life, the driveshafts twist with torque. In LFS they don't, but the tyre model compensates handsomely for it. The net result is that you can get some slightly unrealistic LOOKING behaviour in a stationary car, such as that shown in the tyres.spr replay.

[Greboth]

I havent read this whole thread so i dont know if this had been posted. Also im not really able to post about tyres as i dont know enough. Its a video of drag racing, not track racing so there are differences but it shows how much tyres flew under acceleration and it amazed me and i thought it might show some people who think lfs tyres flew too much how much tyres can flex.
click here for video (http://www.youtube.com/watch?v=9O0b90G8Yhg)

[DeadWolfBones]

I havent read this whole thread so i dont know if this had been posted. Also im not really able to post about tyres as i dont know enough. Its a video of drag racing, not track racing so there are differences but it shows how much tyres flew under acceleration and it amazed me and i thought it might show some people who think lfs tyres flew too much how much tyres can flex.
click here for video (http://www.youtube.com/watch?v=9O0b90G8Yhg)

That's the same video that was posted just above.

[KiDCoDEa]

I havent read this whole thread so i dont know if this had been posted.

:thumb: :D classic!

[BigShox]

Pressure - 3. Abbr. P Physics Force applied uniformly over a surface, measured as force per unit of area.

I'll get me coat :razz:

By the time I got to page 4 I had to go back to page one to remember what it was all about....

[Greboth]

That's the same video that was posted just above.
I said i hadnt read thread :razz: :shy:

[5th Earth]

Another thought on why tires have less load in the center than on the edges.

The angle where the sidewall meets the tread is semi-rigid--that is, the tire will deform in such a way as to maintain this angle. If the sidewalls are compressed and as a result bulge outwards, this will create a torque on the edges of the tread, causing the center to lift. See picture for crude rendering of this dynamic.

In all honesty this effect is probably miniscule in real life and not modeled at all in LFS, but it was a thought that occured to me, so I figured I would post it.