I'm on a coffee / beer / choclate diet; perhaps I'll try to make sense of your art there later Android

Here is the real f3000 data.

Front and rear, the results at 8 degrees lateral slip versus mu at 300, 450 and 600kg.

Last edited by Niels Heusinkveld, Thu, 13 Dec 2007 19:18.

Depending on the FPS you get, FF 'flapping' tends to happen when you set the forces too high. During yesterdays LFS online-a-thon, driving various cars, often 20% in game FF strength was about enough to actually deliver the full force of the G25. Setting this higher causes flapping/oscilations easier, specially at lowish fps..

Configure your mouse for driving and see if the fps are noticably different. I doubt they are; big fields are fairly FPS unfriendly even on decent processors.

Its probably been like this but just more noticable because of the FF issues?

The Antec truepowers are fine; and indeed 550W is about 250 more than you need

Yeah good point... I'm far more sure that something is wrong than I am sure WHAT exactly is wrong..

Won't hurt to compare LFS to the Avon data though.

Edit:

Quote :

If you lift off in mid corner moving all the load to the front tyres, they will indeed lose lots of efficiency, but they will still provide more lateral force than the rears.

Absolutely. Still, I think my argument would stand; as we're talking relative changes. Perhaps nothing is wrong with LFS's load sensitivity; but if there is, the result from lifting mid corner would mean more understeer compared to how LFS currently is; even though on an absolute scale the fronts can develop more lateral force than the rears. The diffrence will become smaller with more pronounced load sensitivity.


Edit2: Pic attached of simplified straight line load sensitivity from an unknown Avon single seater tyre; more later..

Last edited by Niels Heusinkveld, Thu, 13 Dec 2007 11:26.

Of course.. 'weight transfer' is often used; and what's wrong with that? If you put large weighing scales under each wheel, which would be kinda tricky to do, they'd show more weight.. But thats not about load sensitivity anyway. I suppose a couple % of non linearity could already do a fair bit, as it happens on the front and rear.

Cool AndroidXP, looking forward to that! Could you plot friction i.e. (lat force / vertical load)? I'll do the same on the F3000 excel thingy that should be on my HD somewhere at home..

Hiya,

There haven't been too much threads about it but this one (old!) http://www.lfsforum.net/showthread.php?t=4214 shows a plot from LFS. I heard (blame Axus ) that load sensitivity was not or not modelled to a significant extend. I quite like LFS again with the patch; especially the 'race' cars have improved. I wonder how much of the remaining problems I have are down to load sensitivity not being modelled or not being modelled to a great enough extend.

There is lots of AVON excel data available, measuring lateral force at quite a few loads. It would be pretty easy to come up with load sensitivity curves for f3000 / f3 / fford tyres based on this data. I also have some numbers from Goodyear rubber from the Z06 Corvette. So should loadsensitivity not be modelled in a detailed way; I don't see why as there is lots of data around based on which you can realistically implement it (at least for lateral mu vs load).

Driving on South City yesterday, There is that drifty righthander, short straight, followed by what basically are 2 lefthanders, taken as one ish, the last one followed by an immediate right. I find myself always in some sort of fear at that corner (just one example) as it is so easy to initiate a sort of constant slide, where the effect of lifting or giving it a bit of throttle doesn't seem to change the balance of the car enough to stop this slide. In all cars this can happen and you can sort of leave a long skidmark, even though you're not *really* going sideways or giving driving inputs that could sustain this sliding.

Tyres are complex and it could be many things. However, thinking about it, load sensitivity might be part of it. During a long slow lefthander, your grip is mostly mechanical. Accelerating or lifting / braking a little mostly changes the load on the outside front and rear.

Now if load sensitivity where not modelled; the effect of lifting (which is what I'd naturally do) would not change the friction coefficient on the tyres. Load would change (weight moves to front) but the grip increase is linear. Hence the balance of the car not necessarily changing.

Now if load sensitivity is modelled, and I do the 'natural lift', weight would go to the outside front, making its friction coefficient drop a bit, causing some understeer. The rears have more lateral grip in this case as there is less load on them, plus you take away longitudinal force. Lifting would, I imagine, have a pretty siginificant effect on mild slides, straightening the car out, after which you can try again and apply power.

I also notice in LFS the general risk of oversteer on corner entry. Hard turn-in would load the outside front a considerable amount, loosing just a tad of efficiency and grip there. Washout some call it, is lacking, imo, in LFS. Braking into a corner is the 'worst case' for the tyre; lots of sudden load on it. It seems to have no effect on grip in LFS. Take T1 at Blackwood (the right hairpin) for example. Turn-in is unnatural to me, how there often is almost no risk of washout yet easy lift oversteer can happen very late into the corner, and once the slide has started, lifting or acceleration (change in front/rear load) doesn't seem to do enough.. I find myself somewhat unrealistically just choose to sustain the slide which costs far less time than trying to stop it and drive smoothly out of the turn.

Still, tyres are complex, this may be down to force combining all again but I think load sensitivity might be part of it. Since, as said, there is plenty of real info available to derive it from, I see no reason why it can't easily be improved, SHOULD it not be right at the moment.

The thread I linked to at the start of this post; perhaps someone can try to plot lateral grip at various loads with X30/31? Say the F08; which we can compare to the AVON formula 3000 data..

Whadda y'all think?

Last edited by Niels Heusinkveld, Thu, 13 Dec 2007 08:39.

I'll admit that I did spin a few times and had to drive away. As soon as I know I'm going to spin, I fully press the clutch. Driving away depends on what you want; harsh with a bit of wheelspin doesn't heat the clutch, smooth road car type launches do, a bit, but even then I drove away a few times with the clutch temp still in orange; never red!

I haven't been hit from behind yet, though I did notice the AI needs some tweaking in this regard..

Are we all playing the same sim??

Yesterday I was online driving the new BMW, Lx6, F08, FZR and umm the 4wd gtr thingy and not once did the clutch heat up more than it did on initial driving off from the pits.

I don't understand how one can heat it up? Or is it the auto clutching? With 3 pedals and a H shifter for the cars who use it.. No issues whatsoever!

Uber Join!

The LFS demo was and is very generous! 3 cars, one track, no time limits, even online is unlimited!

And now, people can drive entry level FWD, RWD and single seaters, exactly the cars that are in LFS, but then if you want the higher end and MO POWA! you buy S2. The formula BMW would probably convince me to buy S2 a lot better than the tintops. But that is personal.

That the demo now represents S2 a lot better is pretty much a fact and therefore a good thing. If you miss the turbo soo much, it means you play it a lot, which means you should save up for S2..

Good story! haha

There is no relationship between speed (laptimes) and controllers or wheel range. The car is the same and unless you run a single seater at 900 degrees steering, a good lap is a smooth one, not too busy on the steering front..

Realism is a good reason. The G25 at some 400 or 500 degrees is much closer to real single seaters than any of the other wheels available. Needless to say, driving a road car with a ~210 .. 240 degrees turning wheel makes little sense, your steering is bound to be 3, 4 or 5 times too sensitive.

In this regard, I'd even like it if its not quite realistic, as long as there is a way (nursing / carefull lifting) to make it last a long race. Its about time we treat our cars as if we owned them!

In sims I find the view shake to distract from my ability to 'read' what the car is doing. I tend to settle for little or no shake. Its a cool effect that may add immersion but it makes it harder for me to find out where I am in relation to crashing or spinning out.

I didn't test extensively yet but the LX6 didn't heat up its clutch during a few laps, if there is no slip there is no heat and proper blipping and lifting avoids slip..

I embrace the idea of 'nursing' your car during a race because it is one of those big areas where sims haven't punished us enough until now.

I did notice you can't do a lot of starts in the new BMW, but I did a few laps, even spun and had to do two clutched launches, and it was still fine, even cooling down a bit during the next laps.

Still, not tested thoroughly but I haven't encountered heat issues yet..

Though I always want more, the changes in engine inertia seem to have helped the single seaters especially, and the gearbox things are neat. Good going. The F1 without TC is a lot less nervous now because of it, if my memories of the pre patch handling are correct.

AI is well made! Though an AI only race with all the 20 different cars is a little .. hard for the poor fellas.. Very impressive coding though; so good that I accept that the tyres haven't been worked on; at least this patch shows that quite a bit has happened over the last months.

Ahoy! LFS

I sacrifice everything for framerate, making sure its 100+ all the time. This gives swift response and non jerky FF. I also don't run vsync and have the 'frames rendered ahead' to zero.

Sudden jerks might also mean you have not set the max force value setup properly; its some 6500 for the corvette. If you use a G25, you can also set the extra options in the realfeel file to smoothing level zero. Damping should be 11500 for the corvette which equals 'no damping'.

So 11500 damping is no damping, and smoothing level 0 is no smoothing. This, a 100+fps framerate, a max force set to ~6500 and a G25 is what I use..

I use about 107% in the logitech software but still there seems to be a slightly 'damped' and weak zone near the centre. IMO LFS and rFactors FF are perfectly fine. If you measure a G25 and look at how many steps of foce it delivers with the wheel held still, it maxes out at about 10 steps. So you only feel 10 different strengths of FF.

At least 50% of the people I visited and used their FF wheels also had their FF set too strong so even small sim forces caused 100% force feedback on the wheel. Just yesterday I did some GPL at a mates, who likes his FF to be binary.. on or off.

Wheel quality and how we set them up are the main reasons why FF isn't as good as it can be. But still perfectly fine with a G25 and a decent setup. Even if you spend 1400 euro on a VPP wheel you'll still have many of the drawbacks so it seems we just have to settle with a G25 being the best humanly available wheel.

Kompa, I don't think I'll fire up LFS until the new patch comes.. Plus it wasn't so much a test of a car in LFS, more looking at the differences in 300 /600 / 900.

Ade, understandable thought; but nope, I wanted the game..umm sim to be the same. So it would *desire* the same thing from the steeringwheel. The G25 just had either 300, 600 or 900 degrees of steering to do. The sim didn't change, just the wheel. So ideally the car reaction would be the same, just the G25 having to turn more / quicker in order to keep up with the sim.

Current sims like LFS, RBR and rFactor with RealFeel, have far more advanced force feedback than our wheels can transmit back to us. It would be fairly pointless to improve the software side of the FF considering the lack of fidelity in the wheels. And this comes from someone who uses a G25!

Oh dear, why are there so many companies making money with '(lack of) style over content'?

I recall mailing this flash looking Corvette ''aero kit'' company; asking that, since they modified the undertray and had wings etc on it, what the difference in lift or downforce was between theirs and the stock car.

They had no clue, designed just for looks. God knows it may produce MORE lift rather than less..

sigh..

An underpowerd front wheel drive 4 cilinder ''ferrari'' .. Buyers need a firm slapping.

Last edited by Niels Heusinkveld, Mon, 3 Dec 2007 14:02.

On powerfull cars and certain corners it can pay off to short shift; not for fuel use reasons.

Exiting a long corner can be benificial to do 'one gear too high' to avoid having to shift up halfway in the corner exit. The same situation can happen when there is a crest you go over or in general things are downhill. Often, the increased smoothness this gives you during acceleration gives you a speed advantage, even though you might have a bit more power at your disposal if you used a lower gear.

Short shifting can be an important tool for learning smooth driving; you'd be surprised how quick one can be even when half the time you think you should drop a gear. Short shifting calms the car down, and you don't want too many attitude changes.

It is actually one of the areas where often a simracer differs from a real driver; the overdriving we can get away with in a sim isn't so easy in real life, physically and wear/tear wise.

Real cars are good, I'm sure the BMW F1 helped sell quite a few copies of LFS. The Formula BMW is not quite as spectacular but its VERY good news to have any real car in LFS.

When there is a chance of doing a real car, the actual type of car isn't too important IMO, any chance should be taken to include it.

Sure I'd far rather have a Formula Ford (wingless formula cars, not yet in LFS) or some historic formula car.. but for now, more licensed content is a great thing that might lead to more licensed stuff in the future? Who knows.. More Beemers, perhaps a track..

The difference between LFS prior to the BMW F1 and FBMW and 'now' is huge from a umm perspectives perspective.

Nice video!

Scawen is not about to drive slowly in real life, that was good to see.. Lets hope it not only inspired him to do the gearbox but also to get back to the tyres.

Really looking forward to xmas