Quote from Shotglass :

which one of those 2 limits you in the data gathering ? (you mentioned something about limited raf sizes somewhere)

The RAFTyreExtract.exe limited me in my data gathering. Now that I've actually found out the XTRs are simple text files, there was no problem appending multiple of them to form one larger. I already used the output of six RAF files for the screenshots I posted above. It has 69415 data points, which means it basically contains 11.5 minutes of raw driving data

Quote from AndroidXP :

The RAFTyreExtract.exe limited me in my data gathering.

I'll just post my current ('WIP') versions of both programs here, while there is some interest in them. The new RAFTyreExtract should not have the problem mentioned (just checked with over 12 MB RAF). It also works with all 4 wheels and hopefully is more correct then the previous version, though I still know how to improve it further. The new version of MultiDim has two little new features: dimension listing option and double-click centering.

Yay!

E: Speaking of that, how exactly do you calculate longitudinal/lateral "grip"? The reason for my question is because the data looks kinda weird - if you plot lateral grip versus slip angle, the unloaded inner tyre seems to produce higher amounts of "grip" than the loaded one. In my example extract the loaded one peaks at 1.15g, while the unloaded tyre produces anywhere from 1.2g to 1.6g.

If I use "force" instead of "grip", it already looks more normal, with the inner unloaded tyre having a lot lower force readings.

It's very simple:
tyre longitudinal grip = (tyre longitudinal force) / (tyre normal load)
tyre lateral grip = (tyre lateral force) / (tyre normal load)

What you describe is correct (on tarmac at least), it's just load sensitivity, although whether this effect should be stronger or weaker is arguable.

Ahh okay, that makes sense. Thx for the explanation.

As load increases, force increases, but the coefficient of friction falls.

Quote from tristancliffe :

but the coefficient of friction falls.

Huh? You mean after the tyre has peaked?

Edit: Ahh yeah, I see what you are talking about, stupid me.

We're not talking about slip ratio peaks anymore Dave, keep up.

The coefficient of friction for rubber on many surfaces is highest with almost zero load*. As vertical force increases, the lateral or longitudinal force needed to make the rubber increases, but in a less than linear fashion. Thus coefficient of friction decreases with load. With sufficient vertical load, the maximum lateral and longitudinal forces will actually begin to drop, as the coefficient of friction will be dropping very rapidly.

IIRC, the highest CoF achieved for rubber is about 42 (while road tyres are about 0.9, race tyres about 1.5, about drag tyres about 4.0). Try searching for a thread by JeffR on rubber friction and ping pong bats. Might of even been back on RSC.

Now I have read most of this thread a while ago, but dont think I put up a post, however I recently went for an "agressive drive", not saying I know much about the topic, I noticed that there was more wheel spin than I had been used to, comparing to lfs.

(Now, I hadn't expected the traction to be the same, that would be naieve of me to expect so)...luckly I knew the road...

Back on topic, as I have read in this thread, lfs is missing that snap on regaining grip, as well as some wheelspin on loss of grip.

The car I was comparing was, and luckly still is, a 1991 miata w/gready turbo, to the XRT w/normal tires. I know the miata is much lighter ,and shorter, but the turbo waste gate is only set to 5 lbs of boost, wich isn't much so I think the power to weight ratio is about the same. My point is, in my novice opinion, there is not enough wheelspin. So, I guess I agree with the main topic of this discussion.

Edit: Reminder:make sure you take every precaution when going out to the mountains (caution goes with the territory)

I assume your Miata has an open diff?

Quote from Ball Bearing Turbo :

I assume your Miata has an open diff?

It was optional, but I think most did come with the LSD.

Quote from Ball Bearing Turbo :

I assume your Miata has an open diff?

Nope its limited slip, I dont know how many ways though, definately not fully adjustable, but not open any more. Upgrade!!

Edit: and it didnt have a LDS when I got it. Aperently according to the above statement.

And it had the LSD at the time of the insident.

Weheelbase of car, weight and tireprofile greatly affects how car handles in such situation, but I think too that there could be more of snap, but is it because of setups that there is not now, it is hard to say.

Quote from Hallen :

It was optional, but I think most did come with the LSD.

since he has a greddy turbo, he has a 1.6l miata, wich came with either an open diff, or an VLSD, wich acts as an open diff anyway after a few years.

my 1.8 mx-5 came with open diff, but recently installed an Kaaz (clutch pack) LSD myself

factory mazda lsd's are the Torsen type diffs

Well, I dont want to go saying I am a drifter or anything like that, but, I am into it some and have been for the last 5 years. I was addicted to the sight of drift cars in action since I was little. Despite being an american I did have knowledge of the drift scene in japan from a rather young age despite never visiting the country though.

I started driving 5 years ago and live for speed, since very very early S1 demo's, has walked hand in hand with my progression to being as good as I am in a car at this point.

The latest physics and tyre deformation are the closest I have ever seen and felt to real life. The sensation drifting in real life is only compared to in LFS!

I have personally owned 260hp cars, not boosted, but enough power, low enough weight, and plenty of LSD left to use. It is pretty exact to the XRT at wide open throttle in 1st 2nd and 3rd gears with the wheel spin on cold normal tires, vs, a similar size of "all weather" tires you can get at almost any tire supplier on a 200+whp car.

The confidence to come into a corner hauling way too much tail on LFS is there. But, like the guy with the 91 miata was stating, its not as easy to get a car to spin the tires in real life.

Been there too bud, indeed had myself a 91 Miata, BRG, Hard top, 5 speed, worn out LSD, GC lowering springs, koni shocks, and a mean attitude of wanting to be backwards the second the back end came out over 50mph. Its a terrible car to compare to anything but other miata's.

Maybie compare it to the LX4? That would have the huge caster angle feeling the miata does. Plus just like the miata you are nearly sitting on the rear axle dealing with the center axis of the car at your heels on the firewall. Its just a hard to drive car like a mid rear engine. Props for handling one boosted though!

My current car is a 1989 Toyota Cressida, factory worn down LSD, 3200lb curb weight and a worn out 7M engine putting out in the area of 150hp. That indeed feels like the XRG with a nasty soft setup and normal tires. Pretty much as hard to get loose but once its there your yawning while controlling it due to the ease of driving.

The tire physics, when used properly with the right air pressures and camber angles, act as real as anything I have ever seen.

When I get my camera back, I'm gonna fabricate a mount and get some video of my front tire deforming and then some replay footage, mix it together for a side by side comparo of the same size, pressure, camber measurements, and caster measurements. I have the technology to do this, so maybie Scawen would dig seeing someone going that far to show the "real to life" physics that LFS really has.

Loving this Sim more than words can say. I could wait forever to get my hands on the wheel in S3 with the way the progress is moving now. How can you be tired of everything available so far?!


So far LFS is prefect! If you look at the curve of release, its Prefect!




Ben

Very good post up there.

I think drifting in LFS is very realistic as well. Nothing else comes close.

There is definitelly improvement to be made like you said in apsect of "losing grip, starting drift". But I also think that some things during the spin of the tires have to be adjusted as well. Tires might not be spinning fast enough maybe like someone mentioned, but also there's more to it. How it feels when tires spinning slow downs, how it feels when it spins a lot etc. It just needs adjustements.

Other than that, like "overally". Drifting in lfs is pretty much like in real life, at least in situations that I could compare with.

www.bartdrift.pl also has G25 and started drifting in lfs recently. He actually thinks it is harder than real life and that experienced lfs drifters could easily adjust after some practice, to drifting in real life.

And this is what I love about LFS. It is so "open-minded". You can drive on 2 wheels, you can drift etc. If something can be done in real life, it can be done in LFS too. That's what a proper sim should be. The fact that the physics in sims are mostly used in racing situations is a different thing and not what I'm talking about.

Quote from kamkorPL :

Very good post up there.

I think driving in LFS is very realistic as well. Nothing else comes close.

FYP.

Actually you are very right. Thanks for correcting me. And actually your line sums it all.

No other sim can simulate driving in as many aspects as LFS.

Quote from K. Tsuchiya :

Loving this Sim more than words can say. I could wait forever to get my hands on the wheel in S3 with the way the progress is moving now. How can you be tired of everything available so far?!

I'm definately not tired of LFS and can agree that is IMO thr only sim to get any where close to actuall driving.

of course thats my inner LFS fanboy talking.

Quote from tristancliffe :

I have yet to try an rFactor mod that is even remotely like real life (except of course Niels 'Vette ).

I'll stick with GPL - at least you know you have a decent physics engine underneath.

And no matter how flawed the physics engine, the same thing rings true - crap data in = crap data out. You can't fudge the input data to make it work properly. It might end up 'okay' in ONE scenario, but in a 10 lap race a simulator has to cope with thousands of different scenarios.

Maybe one day... but I'm not holding my breath.

I don't know if you've tried the catherham mod with realfeel (alot of work has gone into getting the suspension correct), but ive done a couple of seasons in that now. along with the vette and 79 mods thats the only ones I think are close in rfactor.

The Vette was nice (assuming you meant Niels') but not something I'd want to drive very often really. The 79 mods didn't feel very good to me. Haven't tried a Caterham mod for a while, and certainly not with RealFeel as yet. I'll have a go at some point and see what I think. But FFB is only part of the problem, and there are flaws in the basic engine that need resolving before I can get much enjoyment out of rTractor.

Quote from tristancliffe :

The Vette was nice (assuming you meant Niels') but not something I'd want to drive very often really. The 79 mods didn't feel very good to me. Haven't tried a Caterham mod for a while, and certainly not with RealFeel as yet. I'll have a go at some point and see what I think. But FFB is only part of the problem, and there are flaws in the basic engine that need resolving before I can get much enjoyment out of rTractor.

Realfeel doesn't seem to be much different with the Caterham than with the Vette. It is a better thing than stock, but still not very good.

I thought the Vette's suspension was way too soft. The amount of squat and dive is way, way too much compared to the real car. I also couldn't figure out why the cockpit instrument panel was just a bunch of blurred gauges. It is probably one of those esoteric settings in an ini file or something that I don't know about.

The thing that is really bothersome in rFactor, and is also a factor in LFS, is how the tires behave when they lose grip. Simple understeer is the best way to feel this. If you go into a corner just a tad hot, and you start to understeer, your front end loses all grip until you slow way down, well below the speed that you would normally enter the corner. If while you are slowing down you enter more steering angle, which would be normal since you are now overshooting your turn in point, the car just won't respond. In my real car (and this may be just my car) if you understeer going into a corner like that, you still have some control. Yes, you have to back out of it as much as you can, but you can still turn the wheel more and get more bite. You start scrubbing the tires and you are heating them up quickly, but you will get more response. And then once you slow down enough, the grip gradually comes back and you stop scrubbing. With rFactor, and to a much smaller degree LFS, you just keep right on sliding until the tires decide that they have grip again. This behavior makes it very hard to do a late apex entry into a corner. You are at a slower initial speed, but the initial steering angle is a bit higher. This seems to cause the tires to break away immediately and you lose any hope of taking the corner quickly.

I have been driving rFactor a bit more lately because somebody released a pretty good version of my home track (they call it Vanport, but it is really Portland International). It really helps you notice some of the oddities of the game when you are driving on a track you are very familiar with.

Next incompatible Patch is coming.

When will we have the longitudinal grip improved?

And the dynamic undertray/wings?

That was the most spected improvement to me and simply nothing comes in that patch. Who knows when will come the next incompatible patch?