Ever since Patch U came out I've been playing LFS a lot more and enjoying it a lot more (as are my friends). However; I was discussing it with a friend today and we're both still convinced there's more work to be done in the physics. I was hoping to get the topic started and say how things feel to me, and maybe get enough responses that Scawen could use the input for further advancements. Now, on to the particulars:

I, and everyone I regularly race with feel that Patch U is a HUGE improvement. However; there is still something wrong with lateral grip. More precisely, there's something not quite right about how cars regain traction. Even in my relatively stock car with street legal tires when the car starts to get sideways it will *snap* back into line once grip is regained (if I let off the throttle, for instance). This still doesn't happen quite right in LFS. The car comes back into line very slowly and smoothly. I feel this should be more...well...violent. The same is true about losing grip, though to a lesser degree. It feels like it comes on quite slowly, rather than being a quick reaction. Instead of "grip, grip, grip, NO GRIP!" it feels more like a linear loss of grip when it lets go. For certain slicks should hit their limit a bit more quickly (high grip limit, but once you pass it it's very quick).

We also feel that there's too much loss of grip on the grass. While I actually kind of like this fact, since it forces people to stay on the tarmac more, it really isn't realistic. The grass in game feels like it's got fresh dew, and is therefore very slick. This should not be the case when driving in dry conditions in the middle of the day. I long for the day when we can get damp tracks in the mornings and hot, sticky tracks late in the day, but until that happens the grass really does need a bit more grip.

Other than those two issues I think the current physics are fantastic. With a little tweaking I think they could be as perfect as possible given the current game limitations.

I'm starting to get a sense of perpetual deja vu...

^
You've said that before!

When I drive now I often think to myself that the devs should have had a drifter in their beta-testing-crew. Then that tester would have told them "Teh patch is teh r0xXorz11 Me b3st dr1ft0r in teh w0rld now11! Meh luves teh patch!!!11" because of the regaining of grip.
(Sorry if I hurt any drifter's feelings. )

Vain

I feel like I've never encountered this discussion before, so it must be
Vuja De.

Anyway, as it's an Alpha release of the second stage, of course we're not 'there' yet.

Thats my swo tents.

Not having investigated it any deeper, this is what I've found while tyre temperature testing:

1) It looks like all tyres, no matter how broad or what type, have their optimum slip angle at about 7-8°.

2) There is no more, or only a very slightly grip falloff after peak grip/optimum slip angle. This was very different in pre-patch U, which also caused the oh-so-hated neverending slides, afaik. See attachment for comparison (all grip curves were recorded at optimum tyre temperature).

3) The grip circle is now more ovalish (longer in the longitudinal direction), not perfectly round like it was in prior versions.


I don't want to state if any of these is more realistic or not, just some observations.

which r4s are those android ? high peak degrees should be realistic on the formulas whereas the gtrs tyres should reach their peak at a lower slip angle afaik

FZR, respectively FZ50 (rear) tyres.

Also, the R3 FZR and FOX curve is identical, the FOX one is just shifted upwards a bit (more lateral grip).

Nice work as usual Android.

Now does anyone have some data like this for any real tire?

Cueball:
The lack of "snap" has been mentioned before. I would think this would happen more low at low speeds, and I still really think that the lack of tactile feedback contributes to this sensation.

I say low speeds because the car will approach a velocity that ALLOWS it to regain grip much more readily than at racing speeds. Visually, this seems to be as apparant in LFS as IRL. Break the LX6 loose with some wheelspin at 30K, 40K, get a little sideways and let off the throttle...that thing will snap HARD. There's no reason to think (from my limited RL experience and some physics based contemplation) that entering a skid isn't going to be somewhat progressive no matter what. I don't think that the ISI Train Syndrome (ISITS for short) of cars on rails that get derailed instantly is indicative of real vehicular dynamics.

I'm also not sure what to say about the grass... I never thought of it being inaccurate, nor have I seen it mentioned, but that doesn't mean you're not right... I know what you mean about damp grass, since on past occasions my bike has (abruptly) informed me that I've ridden through an area recently irrigated. Something to think about.

I also appreciate the nature of your post. (a civilized one)

It's strange that the pre-U curve looks more like what I would expect to see, yet the post-U physics feel much better.

as a comparison: http://code.eng.buffalo.edu/dat/sites/tire/tire.html

Part of the issue is I believe also related to the wheel used. In a 'real life' situation, the front wheels will tend to track the direction of the slide - This can be a quite violent action.

In LFS, the wheel is limited in the speed it can actually turn due to forces that are exerted in-game.

Might be an idea to check how much this actually affects things by setting a really small steering angle - Although this may be somewhat hard to control / quantify

Cheers,

Allan.

One thing I just noticed while comparing my tyre-pressure grip graphs (I'm the king of graphs ): a higher tyre pressure shifts the optium slip angle to lower values, so it's alteast not totally static.

LFS has always lacked any form of 'violent' traction loss and gain... be nice to see it eventually. The lack of real world testing and a reliance on text books / physics, would seem to leave it very open for minor omissions and discrepancies to cause quite a different feel in game to RL At least the majority of physics feel very good, the mechanics of driving still bring a grin, things just happen a little slower, even at 250km/h...
Some cars I've driven behave a lot like this, but most feel quite a bit more violent in their transition between states of traction.

I think there is far more "snap" at the edge of traction now. Remember that 90% of the snap you feel IRL you feel through your body. Watch replays and you will see the cars snap.

^
That's what I was trying to say Woz. Watching a replay yields the results they should, and it looks excellent. You'll never ever "feel" a sim like you can a real car of course. If they made LFS behave more "snappy" then maybe some people would find it "feels" better, and yet it may less mathematically accurate than it is right now. If the G Forces you read in the F9 view were applied to our carcasses, we would agree that driving LFS is plenty violent. Take for example the strait on KYOTO GP Long. Driving a GTR at almost top speed passing the start/finish line as you veer left - the g forces display indicates forces that would have you fighting to hold on and yet it seems like just a mild change in direction simply because you cannot feel it. That in turn does not mean that they should amplify the speed so that it "feels" faster and harder than it really would "look" in real life.

Quote from AndroidXP :

One thing I just noticed while comparing my tyre-pressure grip graphs (I'm the king of graphs ): a higher tyre pressure shifts the optium slip angle to lower values, so it's alteast not totally static.

could you do a comparison or a low profile and a high profile tyre at the same pressure ?

Well, give me a low profile tyre and a high profile tyre (both on a RWD car) and I'll compare it

I feel the same way as BBT on this. Traction return is very voilent in LFS, but you cannot feel the "G forces" on your body, that makes a huge difference in control of the car because your actually able to move freely without trying to counter the forces being exerted on your body. Like BBT said watch the G meter on a spin and watch it bounce around.

Nice graphs, Android. I always had the sense of those graphs and seeing them clears up a lot.
The first set of graphs clearly show why it is so easy to maintain a slide for ages after the patch. The tyre doesn't loose grip at too high slip angles and can thus hold the rear at it's angle until steering-wheel motion dictates otherwise. That behaviour has been buggering me about the patch since the first day.
And on another note:
I'm not a drifter in real life, but when your beginner's car was an RWD sports-coupe slides just happen. But that isn't a problem, I know how to countersteer well. I quickly countersteer and the rear snaps back within an instant. Now I never did these maneuvers at higher speed than 70 km/h in real life, like I do them in LFS. (My car is a bit more expensive than the virtual FZ5 )
In LFS it can takes well over half a second of (constant) countersteer until the rear has retaken grip. A quick stab into the correct steering angle isn't enough, you have to leave the steering wheel at the right position for a while until grip is regained.
Is that the same for real high-speed slides? My only referance are cockpit-videos where it doesn't look like that, but that's hardly an evidence.
(A problem might be that in order to regain grip quickest, I often load the diff with some percent gas, so I can utilize the LSD while regaining grip. This might hinder regaining grip, while still being better than trying to do the same with an unloaded (and thus open) diff.)

Vain

The problem of a single tire model not hitting all the criteria dead-on could be solved by having a few different tire makes, each with their different gripping character, as in reality.

Quote from Breizh :

The problem of a single tire model not hitting all the criteria dead-on could be solved by having a few different tire makes, each with their different gripping character, as in reality.

I like that idea =)

Anyone have any graphs of slip angle on real tires? That will help alot in this discussion.

(here is a basic link for us slip illiterates) http://www.insideracingtechnology.com/tirebkexerpt2.htm

The question is, how do you actually measure such curves in real life? Who knows if all books saying the curve looks like *this* are actually correct? All that mathematics and theoretical calculations are nice, but who knows if they really match reality?

Quote from AndroidXP :

The question is, how do you actually measure such curves in real life? Who knows if all books saying the curve looks like *this* are actually correct? All that mathematics and theoretical calculations are nice, but who knows if they really match reality?

The only people that would really have that kind of data would be the tire manufacturers themselves, or somebody with alot of money to invest. I honestly do not know and I have never felt what a race tire feels like. I have talked to an SCCA driver that runs in their Pro series and he says that his Trans-am would just "snap" after too much loading and his RX8 would gradually lose traction. So maybe both could be true?

Here is another quick link for your reading pleasure http://www.turnfast.com/tech_handling/handling_tractn.shtml

I was suggesting it because Scawen said something similar in the U Patch previews: that for now the different tire 'brands' (Cromo etc) were only different in their sidewall graphics.
I think it'd be a good idea... Plenty of motorsports competitions have lesser machinery beating better teams thanks to tire performance inequalities.

So while it'd be a cheap shortcut to just ignore a different set of a few of all the criterias for each tire brand, and get the others spot-on, it would be analogous to real tires' diversity and might make it easier for Scawen & co.

I don't think it's a tyre diversity issue... tyres of the same profile and purpose generally feel 'reasonably' similar in their behaviour on the road.