Hi there.

I don't know if this already happens. It would be quite worth a lot of time to wait for the new patch. So sorry if this was supposed to be a surprise ...

but

Shouldn't tyre physics be improved in major points to simulate the new "electronic side"?

What is the point of a traction control system, which doesn't improve anything above stupid full throttle acceleration? As long as tyres produce almost the same amount of g acceleration with really bad (high) wheel slip as with good (20 to 40%?) wheel slip, traction control won't be able to show what it should do ...

Same point goes perhabs to braking, as it always seemed to me that fully locked wheels don't make the way to stop significantly longer. Perhabs a little bit, but not as massive as they should.

Out of my Spinoff ABS post:
Just watch here at about 2.20:

http://www.youtube.com/watch?v=ZSqGP...eature=related

This is how much ABS improves braking way on dry tarmac with new tyres if one just stupidly locks the wheels all the time. The small spin will perhabs exxagerate it a bit, but even from 100 km/h the difference should be quite visible.
A very good driver may brake as good as a modern ABS but noone who just locks the wheel unti the car stopped.
This would only result in shorter braking ways on snow or stuff that can be pushed in front of the locked wheel to help stopping, but not on usual dry road. (in the wet there is a even a much bigger difference because of aqua planing under the locked wheels)

In LFS if you brake at 200 km/h with very strong brake setup and just lock the wheels the braking way will be not bad. You won't beat that a lot with sensible, reasonable braking. There should be several car length in real life between a locked and a good braking ...

So next point is the new ABS. It can't show its effectivness. Ok, the main target was to preserve steering and it will preserve steering while braking, but braking won't be better in terms of the way. As said I don't talk about a good driver vs. ABS, which should be about equal with modern systems ... I am talking about full locked wheels versus ABS braking.

______________

To summarize it ... the longitudinal acceleration of tyres in LFS should be corrected to see, if the new systems really work as they should. Both, negativ and positive acceleration.

As Scawen said:
"This is on the mechanical side and the electronic side. We are trying to make a good simulation of the traction control systems and the stability control systems, well known to be a very good feature of VW cars."

So perhabs there will be a fix of tyre physics too. Otherwise traction control system will be quite poor at starts
It is finally time to kill those flaws. Even Need for Speed "simulates" to much wheelspin at drag races and punishes it. All ISI games and even Gran Turismo do this too ...

Cu on track
RIP

Quote from RIP2004 :

Same point goes perhabs to braking, as it always seemed to me that fully locked wheels don't make the way to stop significantly longer. Perhabs a little bit, but not as massive as they should.

because they shouldnt

Quote :

This is how much ABS improves braking way on dry tarmac with new tyres if one just stupidly locks the wheels all the time.

no this is how much not overheating the tyres improves braking
watch the video on the wet road which helps to keep temperatures in check to see a much more balanced comparison and thus a negligible difference in braking distance

Quote :

in the wet there is a even a much bigger difference because of aqua planing under the locked wheels

did you actually watch the video?
besides abs does lock the wheels all the time with short periods of little braking in between thus increasing braking distance compared to well executed theshhold braking

Quote :

In LFS if you brake at 200 km/h with very strong brake setup and just lock the wheels the braking way will be not bad. You won't beat that a lot with sensible, reasonable braking. There should be several car length in real life between a locked and a good braking ...

which is a problem of lfs not yet modeling rapid tyre temperature changes of the contact patch which should be able to heat up and cool down much faster than it currently does thanks to the relatively bad thermal conductivity of rubber and therefore low thermal capacity of the outer layer of the tyre

Quote from Shotglass :

which is a problem of lfs not yet modeling rapid tyre temperature changes of the contact patch which should be able to heat up and cool down much faster than it currently does thanks to the relatively bad thermal conductivity of rubber and therefore low thermal capacity of the outer layer of the tyre

It is modeled (Shift + Ctrl with open F9 display), it's just completely wrong... It's just 2-3° C ahead of the rubber core shown in the normal F9 display...

@Shotglass:

You can read at a lot of sources values for optimal grip of tyres. The values may not all be the same, but everywhere you can read : locked wheels don't have optimal grip, because they slide.

Simple Physics ...
sliding friction vs. static friction. Who wins?
Eventhough a tyre with rubber is much more complex, this simple rule still stays and affects it.

So even if we don't watch at temperatures and temperature would be equal, there should still be a difference. Perhabs then not as much and most likely this is a big part of the "braking problem" in LFS, if it doesn't heat up exactly. Overheated tyres will perform worse.

Just read at wikipedia:

http://de.wikipedia.org/wiki/Antiblockiersystem (german)

Optimal grip is at 20-40% wheelspin. Locked wheels DO have about 15-20% less "stopping power". So still significantly even without overheating.
So 200-0 about 140-150m in a normal car. => with locked wheels about 180m ...

And I watched the video. The situations in the wet were about steering around an obstacle. As we know that isn't possible with locked wheels.

The other part is about braking on different surfaces. There is no real situation where one car brakes straight on the wet with ABS und one without.
They showed different aspects.

As you can read again on wikipedia and other sites : locked wheels push the water in front and the tyres begin to swim. Aqua planing. So locked wheels are very bad in the wet and the difference in braking way should be significant. You can see it a bit in the obstacle avoidance part of the video. The one with locked wheels seems to be much faster when arriving at obstacle than the one which avoids the obstacle by steering.

AND you don't really seem to read how ABS works. It doesn't try to lock the wheel often ... it tries to stay between 20-40% slip ... so it pumps against the braking but doesn't try to lock the wheel. Even not for short periods.

This is just the case with very modern ABS Systems. ABS Plus. They recognize surfaces like gravel and lock the wheels on purpose to use the better braking power of locked wheels in these special situations.

If overheating is a problem it should be fixed too of course

RIP

EDIT:

English wikipedia:http://en.wikipedia.org/wiki/Anti-lock_braking_system

"On high-traction surfaces such as bitumen, or concrete, many (though not all) ABS-equipped cars are able to attain braking distances better (i.e. shorter) than those that would be easily possible without the benefit of ABS. In real world conditions even an alert, skilled driver without ABS would find it difficult, even through the use of techniques like threshold braking, to match or improve on the performance of a typical driver with a modern ABS-equipped vehicle. "

Your opinion of threshold braking is old. It was correct with very old ABS Systems, which regulated very slowly. Modern ABS Systems are at least as good as a really good racing driver ...

But I didn't want to discuss sensible good braking without ABS on track vs. ABS braking. A skilled driver can get as close to those 20-40% slip as well, so he could match it.
Here it is about locked wheels vs. ABS braking. That is a whole diffent matter

As has been said many times, LFS is in an Alpha stage of development. Physics are to be tweaked before it's made final.

Quote from bbman :

It is modeled (Shift + Ctrl with open F9 display), it's just completely wrong... It's just 2-3° C ahead of the rubber core shown in the normal F9 display...

i know but its so wrong it might as well not be there at all

Quote from RIP2004 :

You can read at a lot of sources values for optimal grip of tyres. The values may not all be the same, but everywhere you can read : locked wheels don't have optimal grip, because they slide.

which is a reduction in force of ~20% at worst not 100% like in that silly video

Quote :

Simple Physics ...
sliding friction vs. static friction. Who wins?

neither because tyres dont work that way

Quote :

Eventhough a tyre with rubber is much more complex, this simple rule still stays and affects it.

nope

Quote :

So even if we don't watch at temperatures and temperature would be equal, there should still be a difference.

and guess what there is in lfs

Quote :

And I watched the video. The situations in the wet were about steering around an obstacle. As we know that isn't possible with locked wheels.

the one with 2 different surfaces
doesnt really matter which way the car faces with locked tyres so its a valid comparison

Quote :

As you can read again on wikipedia and other sites : locked wheels push the water in front and the tyres begin to swim. Aqua planing. So locked wheels are very bad in the wet and the difference in braking way should be significant.

except it isnt as you can clearly see in that video

Quote :

AND you don't really seem to read how ABS works. It doesn't try to lock the wheel often ... it tries to stay between 20-40% slip ... so it pumps against the braking but doesn't try to lock the wheel. Even not for short periods.

modern systems may be better thanks to the mechanics damping the higher frequency inputs from the system but the basics are still the same

Quote :

Your opinion of threshold braking is old. It was correct with very old ABS Systems, which regulated very slowly. Modern ABS Systems are at least as good as a really good racing driver ...

go ahead and believe the marketing but the whole point of a road abs is to keep the car steerable and as such it will never equal threshold braking
it might be true for a racing abs but thats a completely different system

@s14

Nobody will disagree.

But for simulating traction control and ABS these issues get important somehow, to make these systems useful and demonstrate the increased safety ...

edit: irrelevant.

Quote from Shotglass :

which is a reduction in force of ~20% at worst not 100% like in that silly video

Yes, there comes the heat problem you said. In the video the tyre is overheating in addition to 20% reduction of force.
I think an addition for marketing ... just brutal locking brakes to show it exxagerated.

Quote from Shotglass :

neither because tyres dont work that way

Tyres are more complex than a block of wood or something. But they use friction too. Without static friction AND sliding friction a tyre wouldn't work. There is some factor of rubber "connecting" to ground but still there is a lot of friction.

Quote from Shotglass :

nope

So how do tyres work? And why then there is a reduced force when the tyre is spinning to much or locked?
I named a lot of sources and there are lots of physics books and other stuff.
You just made a statement of your own ... tyres have nothing to do with friction? Dream on
They are more complex as I said, but still there are some rules which count.

Quote from Shotglass :

and guess what there is in lfs

Show me a replay of you braking from 200 with locked wheels and then SIGNIFICANTLY shorter without locked wheels. Not just a few meters from 200 ...

Quote from Shotglass :

the one with 2 different surfaces
doesnt really matter which way the car faces with locked tyres so its a valid comparison

Its not comparable with a straight line braking test on even underground. ABS has to do a lot more and therefore won't result in a perfect braking distance. It has to adapt left braking force to right one on different grounds.

For real a lot of people will agree that locked wheels on the wet are really bad ... as you can read nearly everywhere.

Quote from Shotglass :

modern systems may be better thanks to the mechanics damping the higher frequency inputs from the system but the basics are still the same

Yes, on the dry they won't really lock the wheels permanently. Just trying to reduce braking force. Perhabs just at the first moment to recognize the locked wheels ...

Quote from Shotglass :

go ahead and believe the marketing but the whole point of a road abs is to keep the car steerable and as such it will never equal threshold braking
it might be true for a racing abs but thats a completely different system

It was developed to keep the car steerable. Right. But if you get a very good point between 20 and 40% wheel slip it will also decrease braking distances as stated on wikipedia in german and english most of the times.

But as I said it isn't about good driver vs. ABS ... just about locked wheels vs. ABS. So no reason to argue about that one ...

Quote from RIP2004 :

As you can read again on wikipedia and other sites : locked wheels push the water in front and the tyres begin to swim. Aqua planing.

Aquaplaning has nothing to do with braking, it happens whenever the water film on the road is so thick that the tyre cannot move enough of it to the sides to get a significant contact patch.

When that happens, besides praying to get outside the waterpool unscathed, you can't do much more. No ABS or anything will be able to save your valuable ass because the only things that kept you sticking to the road, i.e. tyres, are floating happily in water like kids in a pool during the summer break.

Back to your original point, improved tyre physics would certainly be a Good Thing(tm), but not for the reasons you've stated.

@Nightshift:

You didn't understand me

Of course aqua planing can appear everytime. But a locked wheel does help it to appear, because it makes the water film in front of the locked tyres thicker ...

So you provoke aqua planing to happen at lower speeds with locking tyres and therefore increasing braking way.

And i won't disagree that you can do nothing if aqua planing happens. But if you create it artificially by braking without ABS and locking the wheels, ABS would help because it keeps the tyres rotating and therefore reducing the water film in front ...

@dark times:

I just think it would be a good time to implement these ones in order to make the simulation of traction control good ...

Quote from RIP2004 :

Of course aqua planing can appear everytime. But a locked wheel does help it to appear, because it makes the water film in front of the locked tyres thicker ...

It's easy to see that could happen with things like mud or snow, but water? I don't know

The locked tyre pushes the water. Just go with your hand over a wet ground you will push a lot water in front of your hand.
So there is more water in front. The profile of the tyre won't work to get rid of it, if the tyre stands still.

So this increases the water film and helps aqua planing to happen at a lower speed as with rotating tyres.

Just think about the reason for a good profile helping against the wet road. Aqua planing will happen somewhere, but it needs more speed. And then you can just hope to slow down in time before hitting something

RIP is right. Tyres prevent aquaplaning by channeling water. The fact that the car is moving and the tyre is rotating helps to channel out the water, normally very effectively, so in a car you wouldn't normally have to drive much differently (driving normally, not racing or anything) than you would in the dry.

Lock the wheel and not only does water build up infront of the tyre but it locks the tread in one position which is responsible for channeling water. Obviously this wouldn't happen always, but the amount of standing water required to cause aqua-planing would be greatly reduced with a locked wheel. (Or, if you still don't understand, with a locked wheel the chances of experiencing aquaplaning are higher)

Quote from RIP2004 :

So this increases the water film and helps aqua planing to happen at a lower speed as with rotating tyres.

Makes sense, I stand corrected.

No problem. I often learn a lot new things ... as long someone can really explain why or name sources

I think this is only really relevant for a lot of water. Not just a little wet road but really heavy raining and therefore danger of aqua planing all the time but nevertheless ABS will help with the braking way then because of this artificially caused aqua planing ...

But as LFS has no rain or wet roads yet this isn't really important at the moment.
It would be just nice to have a shorter distance with ABS than with locked wheels. I just tested it again in car park and there really is nearly no difference to me.

Quote from RIP2004 :

Tyres are more complex than a block of wood or something. But they use friction too. Without static friction AND sliding friction a tyre wouldn't work. There is some factor of rubber "connecting" to ground but still there is a lot of friction.

yes but it cant be described by culomb friction so neither static nor dynamic friction apply (except when the car is stationary of course)

Quote :

So how do tyres work?

google for papers on tyre modeling

Quote :

You just made a statement of your own ... tyres have nothing to do with friction? Dream on

i never said that youre just making yourself look both like an idiot and like an ass
and it seems to me like weve done this before with apparently little success

Quote :

They are more complex as I said, but still there are some rules which count.

sure but culomb friction isnt one of them

@shotglass
Well, it isn't really that important how they exactly work. Because no one of us will propably be able to explain it into detail and it is just to much and somehow a bit offtopic.

So there is no sense in discussing if there is friction or not or culomb friction applies.

FACT: heavy spinning wheels (>> 20%) won't transfer force very well.
FACT: in LFS they DO accelerate quite well

=> Traction Control right now would be somehow useless.

FACT: locked wheels won't have the best braking distances, neither on dry nor on wet. There can be a big or small difference to a good racer (or ABS)

I tried it a again a minute ago and there is virtually no real difference most of the time between braking with locked wheels (brakes at >> 1000 NM) and braking more sensible.
Show me plz a replay where you managed to brake visually better and it can't be explained by reaction time.

So I won't say FACT here, because I tried it but may have done something wrong. Just show me how you do a lot better from 200 to 0 than really locked wheels.

Agree on the Facts?

EDIT: Perhabs braking distance isn't that relevant. There are lot of different statements in the web. And many say there is just a small difference on the dry. On the wet there is always a huge difference ...

See here for example : http://hyperphysics.phy-astr.g ... e/Mechanics/frictire.html

On dry just a drop off from 0.7 to 0.6 ... still should be visible from 200 to 0.

More important is the problem of acceleration to show off VWs traction control.

Did a quick experiment using my mouse quickly (couldn't be bothered to set up my wheel).

Took an XRG, and used Biohazards setup that he sent me a while back. I took brake force up to 1860, and left the bias alone at 77% or something. I braked at an indicated 60mph to 0. Events took place on FEClub REV accelerating away from the startline. No wind.

Ok so here are my results.

With ABS

Left stationary at 0.5 showing on the clock. Reached 60mph and braked to a standstill with the clock showing 10.92. So, that's 10.42 seconds from 0-60-0 with ABS.

Without ABS

Left stationary with 0.48 showing on the clock. Reached 60mph and braked to a standstill with the clock showing 10.46. So that's 9.98 seconds from 0-60-0 without ABS.

I in no way hold my evidence as concrete. I tried once, not several times to confirm accuracy. It's interesting reading nevertheless.

Somehow fun to test it I tested on Car Park with 2 pylons and XF GTI (no ABS). Set off to limiter in second gear ... than brake hard at pylons.

First setup : very strong brakes

=> immediate lockup at braking ... skid marks

Second setup: a usual brake setup at about 700 NM, a bit more

=> stopped at the end of the skid marks

Saw no difference at all

But it won't matter really if ABS isn't that much worse than good braking. Its useful to safe tyres ...

More impact would be a fix to accelerating problems as the standing start would be more of a challenge and even more difference than now with different reacting times.
Skill would be usefull for a good start then ... not just reaction.

And traction control would help

Quote from RIP2004 :

@s14

Nobody will disagree.

But for simulating traction control and ABS these issues get important somehow, to make these systems useful and demonstrate the increased safety ...

I get the distinct impression that you want to fudge LfS' slip curves to be fudged away from reality to give Stability Programs a better stand...

Longitudinal slip is wrong, yes, and so is probably force combining, but either your exaggerating the problem or you believed the marketing departments of ESP-makers a bit too much... Applying brakes to wheels to counter spinning tyres isn't the philosopher's stone they like to make their products out to be...

Oh, and there is quite a difference between spinning and locked wheels...

@bbman

Wrong Impression I discussed about it years ago. Its my personal main flaw in LFS. I love the LFS physics, but this longitudinal acceleration thing really annoys me
So it has nothing to do with new electronics, but it would be a good time to fix that issue finally.
ABS and locked wheels are another thing, but this didn't bother me for a long time.

I just find it very boring that everyone just starts full throttle at online races. It was quite an improvement that reaction times came in ... at least a bit of difference at start.
I talked about that several years ago ... I discussed it with scawen when the "driving school" part came in.

I'd just love to see that fixed.
The other reason was just Scawens comment itself.

Quote from frontpage :

We are trying to make a good simulation of the traction control systems and the stability control systems, well known to be a very good feature of VW cars.

So this is somehow a reason for Scawen to show those good features. And traction control would be just a bit pointless now.

I was too quick to dismiss the reasons in your original post, indeed it is a relevant point since the VWS has been delayed exactly because of those same electronic assistance programs which you were talking about.

The TC on the VWS may actually be useless (or worse?) at the starting line, but since it's supposed to have an open diff, it would also affect performance in corners when the driver is pushing too hard, if I get this right.

So your limited informal testing would suggest there's currently little difference between locking the tyres hard and cadence braking in LFS, as long as you only take braking distance into account?

But ABS will also be better because, despite many claims of tracks in LFS being 'as flat as glass', it will ensure full driveability over bumps and on sloped sections of the track.

As most set have their max braking force tuned for the hardest part of the track, there will be consequences on the average laptimes. How much of a consequence will depend on the actual track/configuration, I guess.

@nightshift : Exactly my points

TC should be worse at start with current physics, if I am not mistaken. Every bit of throttle lack will result in less acceleration right now.

You are right. It would help if pushing to hard. But isn't ESP supposed to help there? Well TC and ESP are nearly the same today. I think ABS and TC are somehow integrated into ESP.
If we talk with exact terms propably both systems would help. ESP would brake single tyres to stabilize the car and TC would cut throttle.

The main aspect of TC though is accelerating under difficult cirumstances like rain, snow etc. which aren't there in LFS.

So TC would help in some situations ... yes. But you could only get half of the original benefit. It should also help at accelerating from stand. Not as good as a professional driver but better than a full throttle starter.

About ABS ... yes exactly. As long as you just watch the braking distance I didn't see a difference. There should be one. This isn't really relevant for racing as locked wheels are really bad there. No control/steering, destroying/overheating tyres ... => bad corner entry => slow.

But physically you should notice a shorter way with ABS or controlled braking vs. wheels locked braking.
So perhabs longitudinal performance of tyres isn't just wrong at acceleration/wheelspin but also at wheelslip and force transfer.

___________

There will be consequences for both systems. Even right now. But they aren't as much as they should be In the case of ABS this isn't really a big point because the brakingway difference between controlled braking as everyone does in races and ABS braking is irrelevant small. Its more about control and less concentrating on braking as the original ABS was developed for.

In the case of TC it would be a bit dissappointing as it would be just like the old TC in FZ50. It took away throttle in corners ... so no new development there.

EDIT: a corrected longitudinal acceleration with spinning wheels would change a lot in my opinion. Not only the effectiveness of electronics. It would also change general behaviour in corners. Right now there should be to much longitudinal force if sliding with spinning wheels for example. With corrected physics even sliding/drifting should feel different, because there is less power to accelerate the car. Wheelspin Sliding would be even slower I guess.
All cars would feel quite different in a lot of situations. Not only the start.

Quote from RIP2004 :

All cars would feel quite different in a lot of situations. Not only the start.

Sure, I'm quite positive an all-car hotlap reset would be in order and also most if not all sets would have to modified accordingly. It would raise a big wave but I'm still thinking 0.6A, despite the version bump, won't be that revolutionary.

Certainly the ESP is harder to code than the relatively simple ABS, I'm now wondering whether Scawen is busy getting it to work right: he certainly has a reputation for not taking the easy route around a problem, I would expect ESP to be coded quite realistically despite the issue with longitudinal traction, but then the default set would have to use unrealistic values to get close to the behavior of the real thing ?

Maybe the postponement has just given him the chance to do some more code restructuring and optimizations that were originally planned for a later patch, and I'm completely off the track.