Edit: URL fixed
Yo Folks,
Yes, lets try to objectively keep the LFS physics against the light. So instead of 'I feel this' and 'I feel this is realistic', lets see how we can attatch some proper numbers and facts to what we think and feel.
This Lx type video was posted in the 'racing' subforum but I think its worth an attempt at an analytical physics debate, not going by 'feel' but going by videos / numbers.
Here is the vid:
http://www.westfield-sportscar ... tvid/misanomegabusa2.mpeg
Interesting because there is both 'sane keep it gripping' driving and 'insane try to slide the car around' stuff in one video.
Here are my observations, perhaps something can be concluded out of them..
1) It seems that he does the sliding in 2nd and perhaps once even in 1st gear
2) when not deliberatly sliding and/or in higher gears the car NEVER requires opposite lock to keep it on the track despite what seems to be full throttle.
3) the first slide (1m04) isn't really initiated by throwing the car into the turn but just by using a lot of throttle on turn in, in 2nd gear (I think). Perhaps the sudden transition from lift off to throttle unsettles the car.
4)lateral (sideways) grip barely seems to drop with wheelspin. Once he unsettles the car with power on corner entry it seems more forward force from the outside rear tyre that cause yaw torque than loss of lateral grip that causes yaw slide.
5) at 1m20 he gets mid turn oversteer again with power, not really assisting it with the steeringwheel. (I tend to flick the car into turns)
6) The oversteer seems brief as it seems to be a full throttle corner exit but the sliding stops before exitting the turn...
7) The corner exit at 1m31ish is interesting as its one of those oversteer guaranteed things in LFS, yet his car is planted..
8) 1m45 he really seems to want a slide but has trouble getting one going After his first correction a big slide is no longer possible.
9) 2m25 he gets nicely sideways under max power.
Now I think I can make something out of this. Based on the tyre model discussions, most notably the 'new' model by Todd Wason, it seems that traditional combining of longitudinal and lateral forces isn't quite realistic. Now this is just another debate with people being against and people being pro but I think I can now sketch a bit what happens in real life and what happens in sims, notably LFS.
I'm the non-expert on this but I'll give common sense a shot. During opposite lock in LFS, you turn against the corner. If you wouldn't, the lack or rear sideways grip will make you spin. You seem to balance the forces around the car centre of gravity by steering the 'wrong way'. This makes the front tyres roll more or less in the direction the car is traveling at, which basically stops them from wanting to enter the turn. Now what seems to be the case in LFS, when you get wheelspin there is a considerable drop in lateral grip. This seems to be what causes oversteer.
Now I *think* I'm beginning to understand what happens in reality. It isn't so much the drop in lateral force that causes oversteer, it is the torque from mostly the outside driven tyre around the car centre of gravity that tries to push it around.
Tyre models are tricky to understand as there is always a combination of longitudinal and lateral forces at play. With risk of being totally wrong I've attatched a sketch which hopefully nods in the right direction. I'm only looking at pure lateral force in LFS (assuming longitudinal force is relatively small) and looking at pure longitudinal force in the 'real(??)' sketch, assuming lateral grip stays relatively constant, more or less based on drifters pulling about 90% lateral G compared with non drifters, which I heard somewhere, and have no idea whether that is actually true..
Would it seem plausible that such a thing is happening in LFS? I think it might explain its handling to some extent. Imagine driving LFS with the sketch on the right being the case and lateral grip being relatively constant.
Ever so slight slalom turning in LFS tends to cause oversteer by the bucketload. With more constant lateral grip you would certainly not get the oversteer simply because the amount of rear lateral grip available is not much less than what the fronts have available. You would only get oversteer when applying a lot of power in a turn. You would force the rear around the front instead of passively having it overtake the fronts because they have no grip. I.E. you would actually have GRIP on the outside rear tyre that causes oversteer (as the grip causes forward force) instead of LOOSING sideways grip.
Any constructive thoughts on this one?
Yo Folks,
Yes, lets try to objectively keep the LFS physics against the light. So instead of 'I feel this' and 'I feel this is realistic', lets see how we can attatch some proper numbers and facts to what we think and feel.
This Lx type video was posted in the 'racing' subforum but I think its worth an attempt at an analytical physics debate, not going by 'feel' but going by videos / numbers.
Here is the vid:
http://www.westfield-sportscar ... tvid/misanomegabusa2.mpeg
Interesting because there is both 'sane keep it gripping' driving and 'insane try to slide the car around' stuff in one video.
Here are my observations, perhaps something can be concluded out of them..
1) It seems that he does the sliding in 2nd and perhaps once even in 1st gear
2) when not deliberatly sliding and/or in higher gears the car NEVER requires opposite lock to keep it on the track despite what seems to be full throttle.
3) the first slide (1m04) isn't really initiated by throwing the car into the turn but just by using a lot of throttle on turn in, in 2nd gear (I think). Perhaps the sudden transition from lift off to throttle unsettles the car.
4)lateral (sideways) grip barely seems to drop with wheelspin. Once he unsettles the car with power on corner entry it seems more forward force from the outside rear tyre that cause yaw torque than loss of lateral grip that causes yaw slide.
5) at 1m20 he gets mid turn oversteer again with power, not really assisting it with the steeringwheel. (I tend to flick the car into turns)
6) The oversteer seems brief as it seems to be a full throttle corner exit but the sliding stops before exitting the turn...
7) The corner exit at 1m31ish is interesting as its one of those oversteer guaranteed things in LFS, yet his car is planted..
8) 1m45 he really seems to want a slide but has trouble getting one going After his first correction a big slide is no longer possible.
9) 2m25 he gets nicely sideways under max power.
Now I think I can make something out of this. Based on the tyre model discussions, most notably the 'new' model by Todd Wason, it seems that traditional combining of longitudinal and lateral forces isn't quite realistic. Now this is just another debate with people being against and people being pro but I think I can now sketch a bit what happens in real life and what happens in sims, notably LFS.
I'm the non-expert on this but I'll give common sense a shot. During opposite lock in LFS, you turn against the corner. If you wouldn't, the lack or rear sideways grip will make you spin. You seem to balance the forces around the car centre of gravity by steering the 'wrong way'. This makes the front tyres roll more or less in the direction the car is traveling at, which basically stops them from wanting to enter the turn. Now what seems to be the case in LFS, when you get wheelspin there is a considerable drop in lateral grip. This seems to be what causes oversteer.
Now I *think* I'm beginning to understand what happens in reality. It isn't so much the drop in lateral force that causes oversteer, it is the torque from mostly the outside driven tyre around the car centre of gravity that tries to push it around.
Tyre models are tricky to understand as there is always a combination of longitudinal and lateral forces at play. With risk of being totally wrong I've attatched a sketch which hopefully nods in the right direction. I'm only looking at pure lateral force in LFS (assuming longitudinal force is relatively small) and looking at pure longitudinal force in the 'real(??)' sketch, assuming lateral grip stays relatively constant, more or less based on drifters pulling about 90% lateral G compared with non drifters, which I heard somewhere, and have no idea whether that is actually true..
Would it seem plausible that such a thing is happening in LFS? I think it might explain its handling to some extent. Imagine driving LFS with the sketch on the right being the case and lateral grip being relatively constant.
Ever so slight slalom turning in LFS tends to cause oversteer by the bucketload. With more constant lateral grip you would certainly not get the oversteer simply because the amount of rear lateral grip available is not much less than what the fronts have available. You would only get oversteer when applying a lot of power in a turn. You would force the rear around the front instead of passively having it overtake the fronts because they have no grip. I.E. you would actually have GRIP on the outside rear tyre that causes oversteer (as the grip causes forward force) instead of LOOSING sideways grip.
Any constructive thoughts on this one?