The online racing simulator
LFS's Wind Model
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(30 posts, started )
LFS's Wind Model
I tried to search for something on this but found nothing so i was hoping that the general LFS population would be able to help on this.

What way has Scawen coded the wind within LFS. With 'no wind' there is obviously no wind. With 'low wind', what are the parameters of the wind speeds and does the wind actually change direction during a race? Also, does the wind speed vary as time passes. Same question for 'high wind'. What are the parameters of the wind speeds and does this wind change directions and vary as time passes?

Input greatly appreciated =]
#3 - (SaM)
To answer your questions, the wind does vary its direction and so does the speed, just like normal wind.

None means there's no wind, but only air friction.
Low means the wind speed varies between low and normal.
Strong means the wind speed varies between normal and strong.
yea but IMO the wind changes the direction too much.
one lap its backwind next lap its headwind.
u wont have that much wind change in RL.
and i think thats one point why this feature isnt used much at all.

PS. hi J_luo
#5 - Davo
From my testing I've found wind speed to change as well as direction. On high this can really cause some havoc as you have to observe your speed a lot more to be able to judge your braking points and how fast you can go around certain corners. The longer the race the more fluctuation you see from the wind so laps are always different and you can't tell how well you're doing from split times or lap times.
I used to think that wind was 'random' and would change over the course of a race, but after the LXCC league, which used wind on some events, I have come to the conclusion that it doesn't. Once I'd figured out the new braking points, the wind made no difference to me (except when I'd forget the 'new' braking point and use the normal one).

So I'm no longer convinced it does change with time.

Can anyone 100% confirm, with proof (perhaps RAF data can be used to prove it, I don't know) either way?
Wind is set at the beginning of the race, heading and speed, then it stays for the duration of that race, it is then (randomly) set again for speed and heading for the next race.

Wind is constant as far as I can see.
By the way, did you know the side of the tyre that is exposed to wind cools down quicker?
#9 - Davo
I don't have a raf but I've got an mpr where you can clearly see the wind changing speed as you go down the straight. Sometimes reaching 240km/h and other times only 220km/h. That's too much variance to put down to corner exit speed. This was a 54 lap race spanning nearly an hour so the wind changes were certainly noticable.
#10 - Woz
Quote from Davo :I don't have a raf but I've got an mpr where you can clearly see the wind changing speed as you go down the straight. Sometimes reaching 240km/h and other times only 220km/h. That's too much variance to put down to corner exit speed. This was a 54 lap race spanning nearly an hour so the wind changes were certainly noticable.

Changing 20km/h when the speeds are up in the 200s is a tiny change % wise.

All I can assume is you have never experienced a gusting wind in your life?

As I said before... how will you cope with a live track or rain when they are implemented?
If you dont care about a 10% difference in speed when racing then you better be playing Mario Kart...
#12 - Davo
Quote from Woz :Changing 20km/h when the speeds are up in the 200s is a tiny change % wise.

All I can assume is you have never experienced a gusting wind in your life?

As I said before... how will you cope with a live track or rain when they are implemented?

Stop making out that your the greatest racer because you can race in wind and everyone else are dumb hotlappers. You haven't added anything to this thread ontopic except to jump at me for no reason. I'm trying to clear up the confusion about the wind stays constant throughout the whole race is rubbish, because it does change. So get off your high horse and actually add to the thread instead of dismissing others.
How this virtual wind blows is clearly seen when you do burnout and watch in some external view. Smokemod recommended.
Also, flags appear affected by the wind
Heh, the wind model is actually pretty interesting. After the last LXCC event, AS North w/ high wind, the 4 of us ( :rolleyes: ) were fooling about and with my LX6 parked stationary I noted:

A) You can of course hear the wind gusts

B) The sound corresponds with the gusts, as my car would actually roll (tilt) a little bit from the frequent bursts of wind. After changing the orientation of my car so that it was parallel to the direction of the wind, with the clutch in & no brake, the gusts would blow my car foward into Hannu.

C) If you park and watch the flags for awhile, (IE FE), the wind does appear to change direction slightly from time to time. It clearly should not change TOO much, since wind doesn't generally come from random directions IRL - IE, a front moves in a relatively consistent direction.

Quote from AndroidXP :By the way, did you know the side of the tyre that is exposed to wind cools down quicker?

IIRC, this has a big effect on the single seaters since they are exposed to open air more... isn't there something about SS's having the large profile tires they do being related to this somehow? Or tin tops having lower profile tires?
#16 - Woz
Quote from Davo :Stop making out that your the greatest racer because you can race in wind and everyone else are dumb hotlappers. You haven't added anything to this thread ontopic except to jump at me for no reason. I'm trying to clear up the confusion about the wind stays constant throughout the whole race is rubbish, because it does change. So get off your high horse and actually add to the thread instead of dismissing others.

I am not trying to make out I am the best racer and I am the first to admit speed wise I am midfield. It's just the same arguments came out when S2 was released and tire heat effected peoples driving.

People IRL try and race at 105% all the time while IRL drivers prob push 98% as they have to save tires and stay on the track. They have to adapt as the situation, track, tires and weather changes about them and all this things change.

What I am trying to make out is...

- IN REAL LIFE wind is not a constant speed, it gusts and those gusts can jump the wind speed loads.
- IN REAL LIFE people race in the wind.
- IN REAL LIFE people change how they drive because of wind.

LFS is a sim and wind is a real thing that happens IRL, a 10% change is TINY for a gusting wind. I just don't understand why people can't adapt and change their driving.

Personally I ease into a race with wind so I can work out its effects then push but allow a small margin for error. Wind DOES effect how you have to drive just as as you tires heat up you have to change how you drive. When rain is implemented you will have to change how you drive again.

Personally I would like an extra option added called gusting wind that changed speed more. But thats me, sick and twisted, I think it adds some spice to LFS
Quote from AndroidXP :By the way, did you know the side of the tyre that is exposed to wind cools down quicker?

Are you sure of that? Stay stationary with the car after a restart with wind speed set to high. All of the 48 segments of a tyre (also both sidewalls relative to eachother) cools down at the same rate, according to the changing speed of the wind. If less or no wind, then it cools down slower for sure, but the car and its parts don't have an effect on that, unlike the size of the tyre. The bigger the tyre, the longer it keeps warm.

At least that's what I see after checking.
Just did a test and well, if there is a effect it seems to be very little

E: The side exposed to the wind reliably jumped down one degree first (both left and right wheels) for the FO8, so I guess wind affects cooldown, but so minimal that it doesn't make any difference during a race.

E2: Then again, when I used preheated R4's and let it stand around in heavy wind, the tyres were perfectly equal after cooling down 30°C. Guess I was wrong.
Considering the wind is what, 20mph at most? And you'll be averaging 100mph around the track in a formula? The difference isn't going to be pronounced but should still be noticeable.
http://www.lfsforum.net/showthread.php?p=279968#post279968



You did test it in a road car right?

Why would this effect be noticable in the FO8?

e: even with "the side exposed to the wind", IRL it would be totally different from having a fender around the wheel/tire where heat is trapped inside the well etc.....

Try it in the FZ50, or maybe even a GTR.

Quote :E2: Then again, when I used preheated R4's and let it stand around in heavy wind, the tyres were perfectly equal after cooling down 30°C. Guess I was wrong.

Depends what temperature the wind is . The less the difference between the wind and the tire temperature, the less it will affect the tire temperature - this is not linear.

IE 60-65 cools down much faster with a 20 degree wind than 35-40 degree, given same velocity of wind, so discrepancies should eventually even out. Who knows if the rubber on the tires transmits heat between pads either
Quote from Ball Bearing Turbo :IE 60-65 cools down much faster with a 20 degree wind than 35-40 degree, given same velocity of wind, so discrepancies should eventually even out. Who knows if the rubber on the tires transmits heat between pads either

Well, I put on R4's to the FO8 which are at 95°C if I remember correctly. Then I yanked the handbrake (:rolleyes:) and let it stand for a while. At 65°C I let go and it started rolling forward. Perfectly equal temperature all around
I think you misunderstood what I meant in the quote above.

*thinks*

Or maybe not? ... I am confused by what you said (hasty posting at work, sorry for not making myself clear)

Actually, I'm not sure what theory you were trying to prove / disprove with what you said (I'm feeling a bit "thick" today)

I was trying to point out that seeing if the sidewalls exposed to wind/air cool quicker is fruitless in an open wheel car because there will still be plenty of flow to carry heat away from the "inner" sidewall, whereas a proper car () would have a wheel arch to stop flow from affecting the inner sidewall, thus the test should not be with an open wheeler.

Then I was rambling about the temps evening out regardless after some amount of time, due to standard thermodynamic reasons which if implemented in LFS would confuse results a little bit with the type of test you're doing with your handbrake (:rolleyes / FO8.

Hope that makes sense...
Quote from Ball Bearing Turbo :I was trying to point out that seeing if the sidewalls exposed to wind/air cool quicker is fruitless in an open wheel car because there will still be plenty of flow to carry heat away from the "inner" sidewall, whereas a proper car () would have a wheel arch to stop flow from affecting the inner sidewall, thus the test should not be with an open wheeler.

I guess you have a point here, but the experiment showed the same results with an FZR
Hmph.

Ok, fair enough. What about FZ50? Would try it myself but I cannot yet.

I wonder why Kid said that then... I wish someone *cough* Bob *cough* would unban him so he could speak for himself and divulge further information. I miss that guy! :hide:
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LFS's Wind Model
(30 posts, started )
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