Quote from Hallen :

But again, that's just a guess given the pictures and data that we have.

btw this test is in the BMI vol 18 Enduro challenge.
http://www.bestmotoringvideo.com/package/vol18.html

It is old enough to be really cheep at various online stores… or just not be a big sin to find it by other means (e.g borowing it )
and that if you care about seeing how the cars where driven, helping your judgment.

Quote from S14 DRIFT :

Seriously BBT, grow the **** up and if you have a problem with me, add me to your ignore list because you're becoming nothing more than a troll..

That coming form you? Lol yoke yoke

But stil why are elephents a part of this threat?
Becaus il leavethe discussion to you guys becaus i know next to nothing about tyres

Quote from Chrisuu01 :

But stil why are elephents a part of this threat?

Quote from deggis :

http://en.wikipedia.org/wiki/Elephant_in_the_room

It's an idiom.

"It is based on the idea that an elephant in a room would be impossible to overlook; thus, people in the room who pretend the elephant is not there might be concerning themselves with relatively small and even irrelevant matters, compared to the looming big one."

Thought it would fit this issue perfectly, since tires are the "looming big matter" while things like GUI/language addons are the "small and irrelevant matters". Catch my drift?

Quote from Matrixi :

Catch my drift?

LOL Good one

Quote from Hallen :

Any professional driver, as claimed were driving these cars, should be able to keep their lap times within a couple of 10ths on a track that short. Looking at it from that standpoint, that's a huge degradation of the times.

youre talking about laptime variation which has nothing whatsoever to do with the tyres barely getting slower at all at only 1.8% increase in lap time

At monaco gp2 are about 4% slower than f1, yes it is a huge difference...

Really? I heard 5 times faster is a typical improvement.

Only on tires that get twice as hot.

Idiot!

http://www.bayarearidersforum. ... thread.php?postid=2568292

This is info about motorcycle tyres but interesting info still.

Quote from Glenn67 :

Perhaps one of the big differences to real life vs LFS is that tyres in rl reach an operating temp (depending on how aggressive the driver is weather or not that temp is coolish, in the optimum range or abit hot) and are then quite stable with a slight cooling off as the tread wears down.

Were what we currently see in LFS can be a trend where temps keep esculating instead of stabalizing once the have reached a certain level. This could simply be due to the yet incomplete simulation of tyre wear and damage under aggressive driving conditions. i.e. when driving at the limit the surface of the tyre should be getting quite hot but in this state it will also be experiencing rapid wear - if this were to happen in LFS that could mean a reduction in transfer of heat from the surface of the tyre to the inner core of the tyre.
...

bear in mind the extreme setups in LFS that certainly affect the way a tyre heats. Excessive camber of -4;-5 degrees (road cars especially), very low pressures all play a role in getting the tyre temps way above normal. I don't think LFS tyre model is perfect at all, but with limited setup options the general behaviour would not be this far off.
I hope to see big improvements in the future, especially on the tyre wear. It's a big drawback for me that you can drive faster and faster as the thread wears down. That's definitely not right.

A simple metaphor about this issue: LFS tyre modelling looks like such a electric kettle. A quick heating in 5 minutes and finally boiling point. However we need "steam locomotive" system. After the starting temperature level the steamboiler of locomotive must be fed carefully. Over coaling will blow up the steamboiler and inadequate coaling will reduce the temperature.

Joking apart, too many coefficients are in the calculation of tyre modelling.

As I know;

-Tyre model (slick, normal, etc.)
-Tyre compound (soft, hard, etc.)
-Tyre pressure
-Track surface (smoothness and vise versa)
-Track design and ideal race line
-Weather conditions
-Track surface temperature due to weather conditions
-Car type and class (FWD, RWD, torque, etc.)
-Total weight of car (including pilot, fuel)
-Weight distribution of car
-Car setups (almost all of them)
-Pilotage
-G force
-....

So, all coefficients above affect tyre modelling synchronously. Of course their influences differ from race to race. Some of them are dominant in a race specifically, although affect in another race slightly.

Another dilemma.. Does tyre wearing problem slow down the laptimes? Not all the time. (i.e in F1, the best laptimes are reached when fueltanks are nearly empty despite the tyres weared out. Herein weight effect is bigger than tyre wearing efffect.)

Finally, in order to alter this complexity the tyre company advisors for race teams should advise the devs, if possible.

the complexity of the problem is the issue, whatever model is being used for the tires something is flawed, maybe something simple, but its a problem and most of the reason i dont drive lfs anymore. imho i'd settle for the appearance of realism as in forza than a flawed attempt, however close, to emulating accurate tire physics.

Quote from Shotglass :

youre talking about laptime variation which has nothing whatsoever to do with the tyres barely getting slower at all at only 1.8% increase in lap time

where does 1.8% come from?

Quote from lEl E Talon :

where does 1.8% come from?

It's the difference between fastest and slowest laps of a session that amp88 posted data for.

If the lap times were random I'd agree with shot but as there appears to be a clear trend in each session towards slower times over each consecutive lap I think it is fairly strong circumstantial evidence that the tyres do tend to "go off" over the duration of a typical stint. I don't think it is because of overheating tyres though and tend to think it is primarily to do with the change in the tyre over the stint, both in the chemical and mechanical structure of the tyre.

Quote from Glenn67 :

It's the difference between fastest and slowest laps of a session that amp88 posted data for.

If the lap times were random I'd agree with shot but as there appears to be a clear trend in each session towards slower times over each consecutive lap I think it is fairly strong circumstantial evidence that the tyres do tend to "go off" over the duration of a typical stint. I don't think it is because of overheating tyres though and tend to think it is primarily to do with the change in the tyre over the stint, both in the chemical and mechanical structure of the tyre.

Yes, but the chemical structure change is 99% due to heat. I think that it the degree that the chemical structure changes is going to be related to just how much heat was applied.

Mechanical should not go off over a 20 minute session, at least not enough to notice. The only way mechanical is going to go off over that short of a session is if you have really bad quality tires, are outrageously abusing them (eg catching the inside of curbs, off roading, under pressured, etc), or you are over heating them.

Quote from Hallen :

Yes, but the chemical structure change is 99% due to heat. I think that it the degree that the chemical structure changes is going to be related to just how much heat was applied.

Mechanical should not go off over a 20 minute session, at least not enough to notice. The only way mechanical is going to go off over that short of a session is if you have really bad quality tires, are outrageously abusing them (eg catching the inside of curbs, off roading, under pressured, etc), or you are over heating them.

I do agree that the chemical change is likely to be the most significant part, but at the same time I can't definately say that the mechanical condition of the tyre desn't have significant impact. I've read that approximately 70% of the grip of a tyre comes from mechanical keying at a microscopic level with the remaining being provided by adhesive properties. That would indicate to me that changes in the adhesive qualities will have a larger effect on lap times but changes in the ability of the tyre to grip mechanically will also have impact although perhaps not as significantly.

HAHA Thats remiands when i ride FBM on worn out tyres, maybe i am good driver only thing what can stop me is otcher player who hits me into Sand trap.

Quote from Glenn67 :

I do agree that the chemical change is likely to be the most significant part, but at the same time I can't definately say that the mechanical condition of the tyre desn't have significant impact. I've read that approximately 70% of the grip of a tyre comes from mechanical keying at a microscopic level with the remaining being provided by adhesive properties. That would indicate to me that changes in the adhesive qualities will have a larger effect on lap times but changes in the ability of the tyre to grip mechanically will also have impact although perhaps not as significantly.

I think that the heat changing the chemical composition will have a big effect on the mechanical keying of the tire. This also has an effect on the adhesive properties because the tire can't conform as well to the surface it is on and therefore less surface area will be in contact. Basically, the tire gets harder through heat cycles eventually. There is a point where the tire gets soft enough that it keys better, but once it is past that point, it does lose a lot of material and the keying won't work as well because the material does not "snap back" into its original shape. It will never work as well again after that.

Big chunks falling out of the tire will obviously have disastrous effects on grip. But that is a pretty extreme result

Quote from NoFear1989 :

HAHA Thats remiands when i ride FBM on worn out tyres, maybe i am good driver only thing what can stop me is otcher player who hits me into Sand trap.

Speaky English??

Wow, just looked at this previously attached chart:

http://www.lfsforum.net/attach ... id=84681&d=1242816769

Thats insane. Looks like the author saw a longitudinal slip vs force chart, and replaced the x axis with temperature.. The crap people can publish in a book these days eh!

Yeah, pretty scary