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Yes, that's about right for % slip nowadays. The data I showed here are on very old tires. Back then they used to be a lot more flexible, so peaks came in at very high slip ratios and slip angles. A bit like GPL tires really
Quote from jtw62074 :
These are old street tires rather than racing tires, but at least it's something concrete to put numbers too.

how old? Bias ply?

Quote from jtw62074 : Opening up these in Paint and counting pixels it can be seen that the first curve drops 9.5% from the peak out to 0.8 slip ratio, which is BIG slip. These tests were done at 20 mph, so you're spinning the wheels up to the equivalent of 36 mph at the far right of the graph. The second test only shows a 3% drop.

That slip ratio is nothing compared to the ones encountered in LFS. Slip ratios from 5 and up are perfectly achievable off the line in many of the cars.

Quote from jtw62074 : Is massive wheelspin going to reduce acceleration? Yes, it could depending on the tire, but generally it's not a whole lot or some massive drop off like most people seem to think where the acceleration dumps down to 60% of what you'd otherwise get or anything like that.

Do you have any further data or info to share to make me believe?
Your old street tyres are dropping 10% at a fairly modest slip ratio, racing slicks dropping 40% at higher slip ratios doesn't 'seem' unreasonable to me. Slip ratio with a clutch dump off the line is always going to be pretty damn huge as far as I can see?


Quote from jtw62074 :
Now that the tires have been improved so much LFS is really at the point where the lack of physical feedback imho is a valid argument. There are still a couple of little things I'd critique, but so far nobody has noticed or mentioned them so I'll remain mum

What fun is that? No need to be shy...
Quote from Blowtus :What fun is that? No need to be shy...

Yeah, seriously, speak up. One of the main benefits of having these staged releases is that the users get to voice concerns and bring issues to the dev's attention and potentially help to make LFS better. I would hope that the devs welcome well-founded, constructive criticism, especially when it comes from subject matter experts.
@viper : I know what you are saying. But I think some kind of traction control or even ESP, which is slower but easier to control, would be a better solution than using very strange tyres ...

@jtw :

Interessting data there. I didn't find a lot of data on that subject. I don't know how much % grip is lost with full throttle.
See Blowtus perhabs. How is slip ratio calculated? In the XF GTI tyres are spinning with about 60 kph, while car starts moving from 0. So at the peak point there is a difference of 50kph to 60kph between tyres and car.
What slip ratio is that?

I just know for sure, that the difference IRL is more than a car length and very noticable, even if driver starts to correct it and doesn't stay fully on the throttle. With road cars. In race cars it should be even more noticable. Watch Touring cars or formula 1 partly ...

Not only in car shows or races on TV, but also in my car it is noticable. In the dry ...
But I did it only once, because it gets pretty expensive IRL to spin the wheels really hard. But also trying to start good at a signal you'll notice that it gets worse if there is spin.
I think the 6 or 8% perfect slip aren't really far from the point where you don't notice slip at all in the car. Tyres always slip to some degree to move the car.
I don't know if it is perfect, but in RL I try to get as less feelable wheel spin as possible to be fast off the line.

But what is your oppinion on the results of the current LFS physics? Do you really think less than 0.1 seconds on 40m between full throttle all the time and a try of a controlled start is realistic? That should be about 1m difference.

________________________

Perhabs two other points of LFS physics that seem wrong to me.

Firstly the stopping way of locked wheels. I should test it again in Patch U, but I think it is still the same. Fully locked wheels stop really well in LFS, which is very strange.
It is very hard to stop better with controlled braking.

Secondly, and it isn't perhabs a real physics problem ... the FZ50.
Something in the simulation of that car is strange. I am really no expert on this, but I think it really overreacts on weight transfers. It starts to slide very very easily.
It is correct that old porsches (rear engine) were very dangerous on braking. But the FZ50 is a bit off. Perhabs something about the static parts of suspension which can't be tweaked in setup? Something that isn't simulated correctly yet?
Current porsches drive way easier. But I would say, that even old porsches aren't sliding that much ...
road cars like the fz run into serious trouble with a locked dif on high speed circuits, really lacks rear end traction on the fast sweeping corners. A clutch pack with high coast lock and low power side makes it very driveable, I thought it felt pretty good but I've never been burdened with the task of driving a rear engined pig in reality either
@blowtus : Yeah, I played a lot with the differentials. That's why I noticed it really.
If I use an open diff its quite drivable in terms of throttle in a corner. But then you'll really notice how slide-happy the FZ50 is just by getting your foot off the throttle in nearly every situation I couldn't fix that with a setup.
that was why I suggested a clutch pack with high coast lock - much more stability when you lift off.
But now we're sliding off topic...
Some information regarding grip under accelerating and braking. http://www.insideracingtechnology.com/tirebkexerpt2.htm
Clutch pack would be the best choise for any car, currently the lack of a preload just hampers all the benefits so there is no point using it.

I also attached a graph showing lateral force vs slip angle under various vertical loads.
Attached images
lateral_force.jpg
RIP2004

I donno, from all these posts to me people are asking for a tire that at higher slip angles has more traction loss. This would require a new tyre.

The problem with compairing LFS to real cars is that the gear ratio's are different. That makes a big difference in the amount of torque going to the wheels under launching.

One reason why you do not see alot of wheelspin in racecars is because they run such light clutches that it's not possible to dump them without killing the engine. Some cars more than others but it does make a difference. Launching a car hard causes alot of wear on the engine and driveline parts, that could be another reason why you do not see alot of tire spinning.

I think LFS "could" use a tyre that is a bit more challenging to drive, if the tyre now is kept for the casual player. Then leagues could run this more challenging tyre maybe?

Blowtus
If you are smooth with your steering, braking and throttle inputs locked Diff is very managable, thats all I use, clutch pack always likes to light up the inside tire for me under heavy cornering, and lets go when I don't want it to.
Quote from Viper93 :
I think LFS "could" use a tyre that is a bit more challenging to drive, if the tyre now is kept for the casual player. Then leagues could run this more challenging tyre maybe?

Current slip curves are true with regular road tyres, however it's a different story with racing slicks.
Racing slicks reach their maximum lateral force at a lower slip angle(around 5-8 degrees) and then have a fall-off in the curve. According to android's graphs slicks pull the same lateral force from around ~7 degrees of slip until 16 degrees and above. You don't need to be a rocket scientist to understand that this behaviour cannot be correct.

The fall-off would be enhanced even further with winged cars if yaw affected the amount of downforce achieved. As the loss of downforce happens, the vertical load on the tyre is decreased and therefore the maximum achievable lateral force is greatly reduced.
This in combination with a more realistic slip curve would most likely make the cars behave more snappy around and above the maximum slip angle.
Quote from plehto :Current slip curves are true with regular road tyres, however it's a different story with racing slicks.
Racing slicks reach their maximum lateral force at a lower slip angle(around 5-8 degrees) and then have a fall-off in the curve. According to android's graphs slicks pull the same lateral force from around ~7 degrees of slip until 16 degrees and above. You don't need to be a rocket scientist to understand that this behaviour cannot be correct.

Hehe thats what I was trying to say but not saying it the right way illepall Duh stupid me Thank you for saying what I should have said in the first place
Every car in LFS slips off too slowly still. While the patch increased overall grip, it still is pretty off concerning sliding. When you can get a better start by revving the engine all the way and dropping the clutch, you know there is something still wrong.
Viper - there are many different tyres in LFS, they all exhibit the particular characteristics being discussed. Keeping unrealistic (if it is decided that they are unrealistic) tyres as a 'main' tyre choice wouldn't seem at all in line with the way things are usually done LFS style, to me.

Re locked difs: are you referring specifically to the fz50 on high speed tracks, or in general? Try the fz on aston national with a locker and then with an 80/80 (40/80 probably drives better for me though) clutch pack if you want to see the lack of rear traction I was talking about.
Quote from Blowtus :Viper - there are many different tyres in LFS, they all exhibit the particular characteristics being discussed. Keeping unrealistic (if it is decided that they are unrealistic) tyres as a 'main' tyre choice wouldn't seem at all in line with the way things are usually done LFS style, to me.

I thought with all those graphs that it showed clearly that the tyres in LFS grip very close to real tyres, I thought we were past that already. If they make street tyres behave with minimal traction loss past peak slip who is to say that there isn't a slick out there that can do the same thing? Not saying that there are many out there, but surely there has to be at least one.

Srry about the locked diff's I was referring in general.
Quote from Viper93 :If they make street tyres behave with minimal traction loss past peak slip who is to say that there isn't a slick out there that can do the same thing? Not saying that there are many out there, but surely there has to be at least one.

The downside is that the maximum lateral force achieved will be reduced. Also combining vertical forces with high lateral forces(&slip angles) is not that simple. If it was, we would still see race cars sliding all over the place like in the 60's.
So, anyway, my personal conclusion is this:

All tyres in LFS have too little drop off in grip levels when spinning or sliding, and that the drop off is nowhere near violent enough (to be realstic) either. Meaning that cars in LFS are easy to drive even when the limit of the cars grip is reached. I don't think that this is just a problem with braking and accelerating with locked / spinning tyres, but also cornering.

The BF1 is not actually that difficult to drift with a bit of practice, even though there is so little feedback compared to IRL. So SURELY drifting (the BF1) should be basically impossible in a game like LFS, if the pros struggle to do it IRL (I am talking about holding slides, not catching small ones).

One Final aspect which has not been mentioned. In this threadhttp://www.lfsforum.net/showthread.php?t=7194 , we were discussing how volently downforce drops off with yaw of a car with downforce, especially the rear wing IRL. And that this drop off is very much too linear and forgiving in LFS.

One more thing. People have been saying that a car should be more difficult to drift IRL, because of Fear etc... But surely if would be much easier (compared to a game / simulation), to do IRL as you have so much more feedback. If you were to take away that feedback in a game without making the physics any different to real-life, then controlling the car would prove damn difficult, regardless of fear etc...
I give up nobody is understanding what I am trying to say, I think I have to go back to english class....:doh::13:
I am not saying that the tyre graphs are not realistic, I am talking about the whole physics of the car. It just seems to me that although on paper the tyres are realistic in LFS, they just seem much too forgiving in the game... ok
Quote from DaveWS :I am not saying that the tyre graphs are not realistic, I am talking about the whole physics of the car. It just seems to me that although on paper the tyres are realistic in LFS, they just seem much too forgiving in the game... ok

Thank you, I thought what I was saying was being lost. I do agree that grip loss isn't as much as it should be, but like you said I do not think it's so much the tyres as something else.
A question for JTW, if he's still reading. This data on slip ratios is extremely interesting, but I'm finding it hard to anchor some of it to personal visceral experience of car and tyre behaviour. Could you have a shot at plugging in an approximate slip ratio that goes with the following tyre sounds? Assume typical modern road tyres on a normal asphalt surface.

1) Cornering at a reasonable speed, but no recognizable sound except the white noise of the tyre against the road.

2) Cornering just a bit faster, so we get that high-pitched squeaking as we start to encroach on the limits of grip.

3) Faster still, so we get that full-on squealing sound of being right on the edge.

4) Faster again, enough to lose traction and we hear that sick, lower-toned squalling / roaring sound that is so often followed by the crunch of metal and the tinkle of glass.

I've phrased this in terms of tyre sounds when cornering, but it seems to me that all four sounds can also be generated by progressively more violent starts. If we think of these sounds in a longitudinal acceleration context, then we can possibly assign approximate slip ratios to each one, right?

I realize I'm asking a lot here, and it's possible that my question doesn't even make sense. But if it's possible to plug some very approximate numbers in it would help me (and possibly others) to get a better grasp of the discussion.
Quote from Blowtus :that was why I suggested a clutch pack with high coast lock - much more stability when you lift off.
But now we're sliding off topic...

Hey ... offtopic but it really works pretty well

Tested it and now FZ50 really drives acceptable for a real road car. The rest of difference is propably down to some small details and the lag of an ESP system ...
Quote from DaveWS :I am not saying that the tyre graphs are not realistic, I am talking about the whole physics of the car. It just seems to me that although on paper the tyres are realistic in LFS, they just seem much too forgiving in the game... ok


If they're right on paper... then they're right in the game.

To those still contesting the lateral grip characteristics of LFS:

If folks would take note of what Todd is saying, despite your interpretation of whatever experience you think you've had in real life, his informed, well studied opinion is that tires don't "lose" lateral grip when pushed over the limit. If it feels that way to you IRL, then maybe take some actual measured data and learned opinion from the guy who's apparantly studied this extensively and adjust your reasoning and think of better reasons to explain your interpretation of sensory feedback.

Apparantly the steet tires in LFS are not particularly far off. If that graph of the racing slick posted above is based on measured data rather than someone's sketch, then perhaps the racing slicks in LFS could use some adjustment.
@Ball Bearing Turbo :

I didn't see many really serious information, which must be completly right.
Where are many different graphs from different sources speaking of street tyres and not "some" kind of tyre and confirming each other?

There is no information confirming that these are usual street tyres.
There is no information about mad spinning wheels. I just saw it to 0.x
As someone stated we are talking of a slip ratio of a lot more than 1 or am I wrong?
There aren't different serious sources for that information. Could be some curve someone painted by hand.

And then there are lots of informations from videos, interviews with racing drivers, personal experiences ... and I think seeing a car beeing significantly faster is much more convincing than just seeing a graph drop a bit.

IRL there is a huge difference between a good starter and a bad starter. See Walter Röhrl in a usual 911 against some TV reporter in a 911 S with more horsepower on dry tarmac.
Walter Röhrl wins very very convincing with less power.

Then put me against lets say a WR holder in LFS in a drag race with the same setup and same car. I bet you won't see a significant difference from the start. Perhabs after the first 2 gear changes. Why? Because something is wrong there. I don't know if the tyre curves are responsible for that, but I don't know what else could be the problem?
Not finding this point? Well NOONE is really finding that point. You can do a hundred starts and the only difference is <0.1 seconds, while in real life there are whole car lengths differences between street cars?

Watch for example this and don't tell me these are slicks :

http://www.autoblog.com/2006/0 ... eo-audi-rs4-vs-bmw-m3-cs/

Ok it is slightly, but really only slightly greasy. I'll get a better video if I find one.
Look the first start (2.08) in the drag race between M3 and RS4 and how close the M3 is at the beginning.
Then take a look at the start at the real race in the end (9:48). Watch this huge difference and the presenter and race driver shouting "aaah... wheelspin and Tiff's away".

I'll look for better examples of street cars in the real world ...
@ RIP2004: Exactly, which is why I can't understand that some people think that there is nothing wrong. All the cars seem to forgiving...

P.S. I am not saying that LFS is not a good sim, it is currently one of, if not the best out there at the moment.
Quote from DaveWS : All the cars seem to forgiving...

You and RIP appear to be saying different things, though correct me if I am in error about that.

There is definitely enough evidence and information in this thread to put to rest the lateral grip "breaking away to progressively" problem, with the fact that there is no real "loss" of lateral grip as explained by Todd in sufficient detail.

Perhaps there is a margin of area to debate the longitudinal grip characteristics, but it seems to be becomming evident that the "problem" is likely nonexistant for street tires. I notice Todd didn't make mention of slicks, and the graph posted pertains to them.

At least we agree that LFS is a good sim

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