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Physics improvements to BF1
(89 posts, started )
May the aero is not enough complex at the moment because it does not simulate part of the cars that stall and create such instability !
Well indeed, that's what we're saying about the downforce loss at yaw - the aerofoils stall or the airflow detaches, rendering the wing extremely or completely inefficient. So as you yaw you get less downforce, which gives you less grip, which makes recovery even harder.

Obviously modern Formula One cars are much more prone to it than say a Formula Renault or even an F3000, but it's an effect that isn't fully simulated. But give it time, and I'm sure something will be done. In the mean time we have the luxury of a relatively easy to drive F1 car.
You people are talking about the slip angle of the tires, correct?
What about the rudder effect of the side boards that hold the wing elements on the rear wing? Surely they reduce they car's tendency to yaw.
#30 - axus
Quote from Gargantula :You people are talking about the slip angle of the tires, correct?

Not quite... yaw is the angle at which the car is sliding or side-slip angle. It refers to the whole car and the direction in which it is traveling compared to the driection in which it is pointing. What we are talking about is that when the car is sliding, it is much more aerodynamically inefficient, creating more drag and less downforce. When you get into a slide the rear wing also is a lot more ineffective than the front, increasing the difficulty in controlling the car. Furthermore, we were discussing the fact that grooved slicks regain grip much quicker if they hit an extreme slip-angle because it is easier to straighten 5 smaller bits of rubber than one big piece.
Quote from Forbin :What about the rudder effect of the side boards that hold the wing elements on the rear wing? Surely they reduce they car's tendency to yaw.

Their size is really not big enough. The air just goes "past" them, because of the shape of them doesn't block the airflow enough to make enough air resistance. And even in higher speeds the speed adjacent to the face of these side boards don't get very high. The only reason that they are big is probably some FIA rule (or to provide as big sponsor ad place as possible...?).

The air just goes "past" them, because of their shape doesn't block the airflow enough.
#32 - Gunn
Quote from DaveWS :That is how F1 tyres differ to road tyres, because road tyres give more consistant levels of grip when sliding and when not sliding, whereas F1 tyres suddenly let go in a big way.

The cars have a long narrow wheelbase, so typically they would let go in a big way once the rear reaches a certain angle. This would happen irrespective of what tyres were on the car. I don't think any real comparison can be drawn between F1 tyres and road tyres, they are so different.
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(thisnameistaken) DELETED by thisnameistaken
ive seen the video on lfs movies pit i think of this BF1? being run on a South City track...i dont know much about downforce...but it would handle like a real f1 if...it has less downforce....the BF1 and FO8 are the same car almost?...only different hp and engine configurations??
Ok, so it probably is more to with the aerodynamics of the car, rather than the tyres which causes the sudden loss of grip in real life, but surely it would be easier to change the tyre physics in LFS rather than having to make complicated advances to the aero phyics.

As for "Turbocharge", yes the BF1 car does seem to handle remarkably similar to an F08 with TC and much more power, in my opinion.
changing one thing to fix something unrelated is not the way to do a good sim
But I think it's got a lot to do with tyres as well - all the cars exhibit very soft transitions into and out of a slide.
Yes, it´s a good idea.
I'm assuming that LFS doesn't exactly model air flow over a car more rather it tells a car how it should react in any given situation. Each car as an 'air flow' box around it that will shrink or grow exponentially as the car accelerates or deccelerates. Thus giving the car and the surrounding vehicles something to reference against to indicate proper behavour. A fairly complitcated bit of programming without adding in lateral slide movement through air. I'm alos assuming that LFS has 'attack' fronts from which the air will be travelling. I can only assume that this doesn't take into account a vehicle travelling sideways or backwards at very high speeds. So what it does do is give teh vehicle a general effect which ever way it is pointing at what ever speed, thus you will have the same downforce acting ont he car going sideways at 150mph as you would going the conventional way at 150mph. Meaning, and this is my point, that slides and out of control situations are easier to catch and control.

The real F1 car doesn't have the luxory of having uniform Downforce. Once a F1 car goes squirly at nearly 200 mph the lateral forces acting on it are immense. Most of the time, if an F1 car goes lateral at these speed even someone like Schumey is just a passenger.

Until LFS can fully model airflow from any direction in any circumstance at any speed you will never get the BF1 to handle exactly like a F1 car. There is to much design and effect going on to really get a true handle on it. Not unless you could download wind tunnel test info and implement them. But to do that you would need the entire LFS community computing power to simulate real world airflow.

I think LFS is as good as it can get for now. Scawen might get tighter on the code and implement more ideas but it's never gunna be any better than a best guess untill we have computers on our desks that can accuratly model and simulate real air flowing over a real car . . . . in Real time.
Quote from Turbocharge :ive seen the video on lfs movies pit i think of this BF1? being run on a South City track...i dont know much about downforce...but it would handle like a real f1 if...it has less downforce....the BF1 and FO8 are the same car almost?...only different hp and engine configurations??

man....did you even look at the different aerofoil shape of those two cars?!?!?!?!illepall
Quote from Funnybear :
...I think LFS is as good as it can get for now. Scawen might get tighter on the code and implement more ideas but it's never gunna be any better than a best guess untill we have computers on our desks that can accuratly model and simulate real air flowing over a real car . . . . in Real time.

Yes, I can see that modelling real airflow to significantly increase realism would be very complex and required vast amounts of processing power, but maybe there is an alternative more simple way to give similar handling characteristics, tyres maybe?
#40 - axus
Quote from DaveWS :Yes, I can see that modelling real airflow to significantly increase realism would be very complex and required vast amounts of processing power, but maybe there is an alternative more simple way to give similar handling characteristics, tyres maybe?

That will lead to problems at speeds where aerodynamics have no effect. And AFAIK X-Plane already has a CFD model so it can't be that heavy... maybe low-poly car models can be used for a basic CFD model at some point to get this right and not too CPU-intensive.
I personally think that F1C newest (ish) mod RH2005 has the best F1 physics of ANY F1 sim yet, including LFS BF1, much better than 99 - 02 season and RH2004 in F1C. However what lets it down a bit is the relatively poor force feedback, which is much better in LFS, and is why my new favorite place to drive F1 is in LFS. If they could combine the physics of RH2005 with the force feedback of LFS, they would have the F1 sim to end all F1 sims.
I think I can tell a difference between fast and slow corners. When I lose it in the BF1 in fast corners, it snaps so fast I'm in the wall before I can rotate the wheel. This usually happens when I hit a bump wrong or get the slightest amount of rear tire on the grass. This may be due to loss of downforce, but it certainly is unforgiving.

In slow corners, the slides are gentler, and I can let the rear step out a bit for turn-in. I have plenty of time to correct, and nothing weird happens. I don't see how anything is wrong.

Maybe you guys are running too much understeer or too soft of a tire compound. I usually end up running the hardest compound to keep from overheating, and they end up being hard to get up to temp and very unforgiving.
Quote from petrichor :I think I can tell a difference between fast and slow corners. When I lose it in the BF1 in fast corners, it snaps so fast I'm in the wall before I can rotate the wheel. This usually happens when I hit a bump wrong or get the slightest amount of rear tire on the grass. This may be due to loss of downforce, but it certainly is unforgiving.

In slow corners, the slides are gentler, and I can let the rear step out a bit for turn-in. I have plenty of time to correct, and nothing weird happens. I don't see how anything is wrong.

It seems odd that you say that, because having driven the car again recently (on KY GP) I took a curb too much on one of the high speed corners, and it went into a slide. However I find that the car is still too stable whilst in a high speed slide, and i managed to correct it without too much difficulty.

*Edit. (on KY GP) At the slow speed double apex hairpin however, the car is very twitchy and unstable.
Then use that setup you have for fast tracks and find another more suitable setup for slow corners . . . .

I don't see how you can get anything more accurate out of LFS. After all, hace you driven an F1 car to corroborate your supposed discrepancies?
No, but I watch F1 on TV very closely, and the onboard shots give a very good idea of real life handling. Compare a real life replay to a LFS replay, comparing driver inputs.

Plus, have you driven RH2005, the physics simulate the loss of grip and stability in fast corners very well. Like i said its the rubbish force feedback in RH2005 which ruins the driving sensation.
Quote from DaveWS :That is how F1 tyres differ to road tyres, because road tyres give more consistant levels of grip when sliding and when not sliding, whereas F1 tyres suddenly let go in a big way.

How do you people know this? Ever seen F1 tire data?
No, he is assuming it because F1 cars are either gripping madly or spinning off very suddenly. What he fails to take into account is the complexity of real life compared to LFS, the ability of the F1 drivers, and how close each is to perfection and the limit. If you're running within 0.2 seconds of the cars potential every single lap then it's bound to go wrong sometimes, and usually very quickly.
Quote from jtw62074 :How do you people know this? Ever seen F1 tire data?

It was a guess, and I admitted several threads later that the problem was more to do with aero physics. However many people think that the tyres in LFS have too smooth a transition between grip and slide.

Since there are obviously no drivers on this forum who race F1 cars, we have to rely on educated guesses.

*Edit: spelling
Quote from DaveWS :I*Edit. (on KY GP) At the slow speed double apex hairpin however, the car is very twitchy and unstable.

But it is easily corrected, right? That's my worst corner on that track, so I'm not really sure. Part of the instability might be the bumps there.

I just thought of another factor. F1 cars have more area in sideview in the back than in the front. If you are sliding, this would put more sideways aero force on the rear, tending to stabilize the car. I think this would be very important in real life. At low speeds, you have a car with little downforce and a rear weight bias, so it could be very twitchy.

You can say that loss of downforce due to side slip will make it unstable, but that depends on which end loses more downforce. If both ends lose downforce equally, it should just slide more, but not necessarily spin out. If the airflow is directed slightly to the side, the rear seems to lose more air because of the large side elements, but it is also getting cleaner air, because less of it is coming from the driver/airbox area. So I don't think it is obvious what will happen.

Maybe the fact that I'm getting dirt on the outside tire when I lose it is causing a dramatic loss in traction, and I'm confusing that with aero effects. So I guess I don't really know which part of the handling is aero and which is other stuff. But I do lose it plenty when I hit a bump wrong while totally on the asphault. One bad place is the fast, downhill right-hander (T6?) after the 3rd hairpin at the beginning of Aston North.

As for the tire comments, F1 tire data is in the Ferrari Formula 1 book (p. 190), if anyone has it. It looks pretty forgiving to me, especially at low loads (not much falloff in lateral accel for high slip angles). The measurements here don't go past the peak slip angle for high loads, so I don't really know how much it falls off, but the peak slip angle for high loads is very high, much higher than at low loads (10 vs 5 deg). So you should feel like you are sliding more at high speeds and probably should try to keep the car straighter at low speeds. Who knows if LFS's tire model looks anything like this.
#50 - Gunn
Quote from DaveWS :Ok, so it probably is more to with the aerodynamics of the car, rather than the tyres which causes the sudden loss of grip in real life, but surely it would be easier to change the tyre physics in LFS rather than having to make complicated advances to the aero phyics.

LFS development doesn't work like this. Scawen isn't about to change the tyre physics to compensate for some other area. He's trying to make a realistic tyre model and a realistic aero model, not fudge the two until people are happy.
If the aero is not right then yes, he will make advances to the aero physics. This is what drives a wedge between LFS and its so called rivals, here somebody is actually trying to make a simulator rather than just throwing together a crowd pleaser with no real teeth.

Physics improvements to BF1
(89 posts, started )
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