Now you're talking Hallen Good points. I'm not a physics expert so I don't want to get involved in detailed discussion about what's exactly wrong physics wise. I just wanted to say what's wrong from driver point of view and from comments I got from very professional drifters who also have G25.

Thanks for explaining why race tires or well let's say super grippy Dot or Dot-r tires last so long. Because I knew they did, but always thought that they should last less since they are much softer compound (low QT).

I very much hope Scawen is reading this thread.

Quote from Bob Smith :

This has been posted so many times, yet my own testing in LFS has led me to the opposite conclusion. Excessive wheelspin does produce less longitudinal force in LFS, try the BF1 at the dragstrip with and without TC for evidence. Fastest times will be achieved with TC set at the optimal slip ratio. The question is that perhaps the dip after the peak isn't deep enough, doesn't happen fast enough.

True, and I can understand why people feel & say this though because in practical terms it's the way it appears. Especially at ridiculous slip ratios where you would basically just be floating on a film of molten rubber as it were.

It's a bit strange because: you can reach very high temperatures on the surface of the tire in LFS (per ctrl+shift) but it doesn't affect grip as much as when the core is heated, which once again just leads to a possible fundamental error in the relationship between the two. IE - if the core temp in LFS is 150 degrees, the tires feel like they SHOULD feel with a massive slip ratio ('soap'), even though the surface temps can meet or exceed those temps and yet the tire still has plenty of grip.

Android has in the past posted graphs showing LFS's longitudinal grip characteristics, and from what we could tell at the time there was a very small peak, and then a drop which levelled out as far as we could tell. The result is that you're better off mashing the brakes and inducing copius amounts of wheelspin off the line than you are feathering the throttle and being professional about it.

Quote :

I suspect that is modelled, although perhaps not well enough. I'd imagine that the humidity of the air would make a marked difference to the cooling effect, so that's potentially one possible avenue for improvement. Turbulence in the wheelarches might increase the cooling effect (or maybe even the opposite), and road tyres have a greater surface area than slicks, which must help, even if just by a tiny amount. We don't know how detailed Scawen's model for this is. Considering that we don't have hot brake discs warming the air that's cooling the tyres, LFS should if anything have tyres that warm too slow and cool too fast (although I couldn't say how large an effect hot brakes would have on the tyres).

Tires do cool faster on openwheelers in LFS afaik. I would suspect that heat transfer from brakes could be a concern, at least probably moreso on street cars without brakes that rapidly dissipate heat, but I'm no expert in this area. Pretty sure I've read something about it, but I can't remember what damn Captain Morgan!

Quote from Bob Smith :

could the fast heating yet slow cooling be attributed to a lack of cooling effect by the air, as the tyre passes through it? I would still expect a tyre to be heated a lot faster than it is cooled though.

might be
just tried with the bf1 going well above 250 and the maximum difference between core and surface temps that i could see was about 10° which seems a little low to me
also do the tyres cool from touching the road which afaik is at around 20° in lfs?

but the biggest problem ever since we realized that lfs does model surface temperatures is something bbt just pointed out
surface temps dont seem to have any influcence on grip levels but core temps do... intuitively it should be the other way around which should also cause the core to heat up slower as the amount of frictional heating decreases with higher surface temperatures reducing the friction between the tyre and the road surface

Quote from Bob Smith :

This has been posted so many times, yet my own testing in LFS has led me to the opposite conclusion. Excessive wheelspin does produce less longitudinal force in LFS, try the BF1 at the dragstrip with and without TC for evidence. Fastest times will be achieved with TC set at the optimal slip ratio. The question is that perhaps the dip after the peak isn't deep enough, doesn't happen fast enough.

Hi there.

It might produce less longitudinal force, but as you said the effect seems to be very small unlike in real life. The BF1 begins to change directions if you start without TC. So a worse acceleration result may also be caused by the left/right tail sliding. At least some of the result. It's really hard to accelerate full without TC and without spinning

The important point is: it should be quite noticable with every single car in LFS and not only with the BF1, which has extreme differences between wheelspins TC on or off.

Try the same with the road cars in LFS and there won't be a really noticable difference. But Scawen said already he is aware of that problem a long time ago. So at some point there will be a change.
Now with the next patch would be quite a great time for it, as it features ESP/TC and ABS in the Scirocco. And a real simulation of Scirocco TC would be effected nicely by punishing full throttle w/o TC accelerations.
To really show of these systems, better tyre physics would be fantastic.

Regards
RIP

I fully agree with you on the tire physics. In F1 the performance drop from the qualifing lap to race lap is about 3%, and that's mostly because of the amount of fuel they carry and not because of the tires.
Tires heat up too slow after cold start (tire temp should be allmost optimal when starting with tire-heaters) and then heat up further much to quick to hot.
Then grip loss is way to much when tires are hot, it's much like you have a flat or something. I have never seen that much griploss in any reallife race..

Quote from BoneCrusher :

Then grip loss is way to much when tires are hot, it's much like you have a flat or something. I have never seen that much griploss in any reallife race..

a) It's likely that, at the level of motorsports that are televised, such mistakes are very rare in the first place
b) The drivers' level of skill is enough that you don't really see much difference from an external point of view
c) Anyone outside the pitlane likely has no idea about how hot tyres may or may not be during a race in the first place

This isn't defending LFS, you just can't make such circumstantial comparisons meaningful.

One thing i think is overlooked here, is the actual road surface?
This is quite important really, and perhaps this is also part of the puzzle that needs more attention?

Quote from Bob Smith :

a) It's likely that, at the level of motorsports that are televised, such mistakes are very rare in the first place
b) The drivers' level of skill is enough that you don't really see much difference from an external point of view
c) Anyone outside the pitlane likely has no idea about how hot tyres may or may not be during a race in the first place

This isn't defending LFS, you just can't make such circumstantial comparisons meaningful.

Add to that that for any given race serries the choice of tyre compounds etcetera have been sorted and therefore having overheated tyres is less likely than perhaps what we see in LFS

I was reading this thread and also was thinking about temperature cooling/dynamics... wouldn't a hot tire cool faster than a warm tire simply because of the temperature difference from the air around it? it shouldn't be a flat temperature model. I believe I will do some experiments and see what the result is!

Quote from Bob Smith :

a) It's likely that, at the level of motorsports that are televised, such mistakes are very rare in the first place
b) The drivers' level of skill is enough that you don't really see much difference from an external point of view
c) Anyone outside the pitlane likely has no idea about how hot tyres may or may not be during a race in the first place

This isn't defending LFS, you just can't make such circumstantial comparisons meaningful.

Bob makes a good point here. None of us can really say with precision what the effects of tire temperature are exactly. First, even if you drive real race cars or spend a lot of time at the track, you don't push nearly as hard as you do in LFS. You are driving 11/10ths all the time in LFS.

Secondly, the conditions do make a huge difference. Each track has its own characteristics for both grip and how abrasive the surface is. It's extremely difficult to compare.

I think these things makes Scawen's job even more difficult. Getting valid test data to compare against is virtually impossible. And even if he did have that data, it's probably only for one tire type on one surface.

So, there are things that we are going to see in LFS that may be 100% accurate as compared to the real world, but it is so outside any of our experiences, that it seems wrong.

As far as the heat loss goes, I don't know for sure, but it seems that the cooling would not be a linear processes. It would cool more rapidly down from higher temps, but then slow down considerably as the temperature of the tire dropped. This is just intuition, but real physics have shown millions of times that intuition is patently wrong. eg, which weighs more, a pound of lead or a pound of feathers?

Quote from Hallen :

but real physics have shown millions of times that intuition is patently wrong. eg, which weighs more, a pound of lead or a pound of feathers?

are they both occupying exactly the same place?

rofl!

Can always count on Shot..

Quote from Hallen :

As far as the heat loss goes, I don't know for sure, but it seems that the cooling would not be a linear processes. It would cool more rapidly down from higher temps, but then slow down considerably as the temperature of the tire dropped. This is just intuition, but real physics have shown millions of times that intuition is patently wrong. eg, which weighs more, a pound of lead or a pound of feathers?

just got done with my experiment. it seems what we thought is true and is modeled correctly. the graph is attached. please keep in mind that there might be a max difference of .2 to .5 seconds on each time.

Time on Y axis, temperature on X. It was from that temperature down to the next lower temperature. Hope that makes sense.

Quote from jaxx751 :

just got done with my experiment. it seems what we thought is true and is modeled correctly. the graph is attached. please keep in mind that there might be a max difference of .2 to .5 seconds on each time.

Time on Y axis, temperature on X. It was from that temperature down to the next lower temperature. Hope that makes sense.

The shape of the graph is logically correct. It should be an exponential, which it seems to be. As for the values and drop rate I can't comment on the accuracy and realism.

Quote from jaxx751 :

just got done with my experiment. it seems what we thought is true and is modeled correctly. the graph is attached. please keep in mind that there might be a max difference of .2 to .5 seconds on each time.

Time on Y axis, temperature on X. It was from that temperature down to the next lower temperature. Hope that makes sense.

Graph looks ok to me. But what happens to the point when the tire becomes overheated. Perhaps you can test that? In my opinion a tire should not become overheated as easily as it does in LFS, because the warmer the tire gets the more heat it radiates

Here are some articles that a few might find interesting...

http://tyres.wordpress.com/200 ... tyres-and-the-grand-prix/

http://tyres.wordpress.com/2007/03/19/tyres-and-formula-1/

http://espace.library.curtin.e ... 0112&local_base=GEN01

Quote from BoneCrusher :

Graph looks ok to me. But what happens to the point when the tire becomes overheated. Perhaps you can test that? In my opinion a tire should not become overheated as easily as it does in LFS, because the warmer the tire gets the more heat it radiates

the test was done on road supers.

Quote from Glenn67 :

Here are some articles that a few might find interesting...

http://tyres.wordpress.com/200 ... tyres-and-the-grand-prix/

http://tyres.wordpress.com/2007/03/19/tyres-and-formula-1/

http://espace.library.curtin.e ... 0112&local_base=GEN01

Good read - I'll keep the thesis for work boring moments though

Slightly off topic, but only just. I've got this book some of you may find an interesting read.

http://insideracingtechnology.com/booktiredescrptn.htm

Quote from Not Sure :

I hope you are not asking me to scan, page by page, this book and Torrent it!

No, that would be against forum rules and also illegal. Just expressing my interest in this subject in a humorous way.

Quote from Not Sure :

No, that would be against forum rules and also illegal. Just expressing my interest in this subject in a humorous way.

This forum has rules?

I guess..

Well that's enough offtopic!

I'm reading the exerpts from the book atm, good stuff!

I wonder if the tire model in LFS (or any simulator) includes the different types of friction.

I'm with Donald Duck..