bumps are very important.. The tyre model is about as important as the bumps model I'd say. Sine wave bumps like GTR are horrible. RFactor seems to do them a bit better but I'd say its time for a new approach to bumps.. Iracing is now laserscanning tracks or something with all bumps taken into account.. If you can put this in a sim somehow..

Todds tyres almost look too easy but once there are bumps it might be a bit harder.

Sims haven't really moved in the 21st century yet :/

Brian,

you'll get as many opinions as replies to this one

I agree LFS is 'unrealistic'.. The promis it holds is great however. And after long hard work you can actually make the cars hard to oversteer.

Try the attatched setups, though they only are for RWD road cars. It is hard to say what is wrong exactly. It seems like the tyres don't have a transition from grip buildup, stick, grip loss.. you seem to go from grip loss to grip loss as if the tyre barely has a preference of not slipping / sliding.

It has been discussed at high and low quality levels of conversation.. We will have to see what the physics updates before S2 goes final do to the handling. Meanwhile try these setups. I'm now working on a new pack which provides more of a challenging / rewarding drive than these ones that where there basically to make it nearly as hard as possible for LFS to oversteer out of control..

N

Well, I don't really care about how accurate the engine is modelled (and posted this before finishing my reply?!)

Anyway, the power to weight ratio isn't that extreme, the car has slick tyres and the tiniest 'weaving' at speed makes it oversteer. I actually think the low weight 'extreme' might be highlighting the / some physics engine troubles perhaps? At 222hp/ton vs 250 for the Fz50 just to give some idea on the power. Of course the lack of weight will make it a lot more nervous but somehow, at guessed yaw angles of only a degree or 2, is the acceleration force enough to make the rear tyres overtake the front?!

Last edited by Niels Heusinkveld, Sun 15 Jan 2006, 13:42.

Hi all,

Some of the 'kart track' layouts are quite a blast. I think there is something quite weird happening at mid to high speed in the MRT5. Going fast in 1st gear is about the speed where accelerating really wants to make the car oversteer. The 'push' caused by changing to 2nd without lifting is often enough to cause oversteer that violently snaps into the opposite direction. But even in 2nd or 3rd gear there is still enough power to easily cause a snap snap snap / death kind of thing.

I find this VERY weird as at slightly lower speeds the little car had a far greater tendency to understeer on power.

What is going on here?

Oooh I love the one from the original poster! Maniac stuff and about to break the 1:30 barrier.. (or another suspension.. )

Its the ultimate Fz50 'under control' drifter too, very tricky being so narrow. Framerates do suffer with all those barriers!

Good ideas guys! This might be even more important when the sound 'engine' (hoho) improves and gets more complex, but if you can go from 18 to 40fps now already.. this is a must have.

Hmm from the grip vs load graph it seems clear that it is a straight line..

I've been letting Google loose and found this at the catheram official site:

Quote :

When cornering, the wheels on the outside of the turn get more heavily loaded than the inside pair. Load is 'transferred' to the outside. It is natural to think that the outer tyres, being under higher load, produce more grip and the inner tyres produce less grip. This is true, but the total grip produced by the axle pair is in fact less than if the tyres were evenly loaded - Honest! This effect is often referred to as the load sensitivity of the tyres. One way to minimise this load transfer is by generally using a softer suspension system.

I never really knew if load sensitivity was minor or major but this indicates that it is fairly major. The sim "Racer" (Ruud van Gaal) uses the Pacejka tyre model and someone (Alpine at RSC) found some actual coefficients including load sensitivity. With the Pacejka Player supplied with Racer, you can vary the load and see how big the effect of load is on available grip based on some real measurments!

Of course I don't have the real pacejka data on my drive anymore to check..

Edit: source: http://www.caterham.co.uk/aftersales/upgrades/suspension.htm

Last edited by Niels Heusinkveld, Fri 13 Jan 2006, 00:34.

I don't think you will be dissapointed Tristan, they seem very solid and adjustable, have decent electronics, and are the closest to 'force sensitive' you seem to be able to buy on the sim markets.

Tristan, although I think the ECCI pedals are a good product, their brake pedal is not force sensitive. They use a slightly progressive system but applied force isn't linear with actual braking as far as I know.

Their USB connection also doesn't allow axis swapping or inverting which might cause some issues with certain games where the Y axis in particular might only work 50%.

I am of course biased as I made my own which absolutely rock, at much less than half the price of a set of ECCI's or BRD's..

N

I'm most curious why people think a brake pedal needs feedback? I'm not the braking feel expert having only driven road cars but I simply can't imagine there IS any feedback in a real pedal under normal use!

Excessive wear / bioling fluid might make the pedal more spungy but under normal conditions I really can't see why? What am I missing?

The kit is just the sensor (a piece of ~ 13x3x3cm aluminium).. You have to create the actual pedal around it. I don't think there are easy ways to modify Logitech or any commercial set for this, but you can see pictures of my pedal set linked to at RSC which is I think as simple a design as possible if you want a functional and adjustable set.

And if I get 100 people who want such a pedal set I might consider it

Oh and I don't think force feedback would do anything for a brake pedal. If your brake discs are nice and round you don't really get any feedback from the brake pedal. Only when something is seriously wrong does the total feel of the pedal change. If the sim (like GTR) models brake temperature you will find that you have to press less hard once the brakes are at their optimal temperature and you have to press harder when they are not..

Last edited by Niels Heusinkveld, Thu 12 Jan 2006, 09:03.

http://forum.rscnet.org/showthread.php?t=215834

there is my original pack, which includes the LX6 (it can still bite) and RA (hate that car! it either understeers or oversteers you into the virtual hospital )

/N

Hi guys,

Some of you probably browse though the RSC forums but I'd just like to point you to something that is the result of a lot of research and techy stuff by the community and yours humble truly: parts to make a force sensitive brake pedal.

No longer do our brake pedals have to respond to motion, now we can feel the force! Just like real cars work. Anyone who tried my pedals using this force sensor is amazed. It really puts even the most expensive commercial pedal set in the corner for pure realism of operation! And rated at 50kg you could of course use a wimpy 5kg, but hardcore users will use all the 50kg and find out that driving a race car is hard work!

With LFS I always found braking the toughest thing to do. I am much more steady now, as you don't easily 'overshoot' using force. Weaker motion based pedals are easily pressed too far.

Perhaps the coolest thing is driving the single seaters and the feeling of simply loosening the 'tension' in the leg to slowly get off the brakes as downforce levels drop. No movement in the pedal, just pressing it less hard.

Point your browsers at:
http://forum.rscnet.org/showthread.php?t=239373

Regards,
Niels Heusinkveld

Well, it is almost physically impossible in real life. The gear ratio depends on the amount of teeth on coghweel 1 vs cogwheel 2. The cogs need to be strong so they can't be too small. This means that in the space of a gearbox you can't have cogwheels with all that many teeth.

It would be a bit tricky to find out what is and isn't possible perhaps, so something more simplified like steps of 0.05 or 0.1 would be the easy thing to do.

I think GPL uses real gear ratios which might give some idea about the steps encountered.

Interesting stuff!

Ironically I have been looking for the same data but didn't really find a lot in the 30 minutes I googled.. But sadly I'm not alone in this LFS Fz50 world

Driving Antsa's setup almost makes LFS 'acceptable' but still the Porsche death rate would be rather high if it was real. I did a quick experiment of taking Antsa's setup and doing two laps with the exact setup and two laps with normal front tyres, which has helped a LOT in improving LFS for me.

IMO the setup is not nicely balanced whichever tyre used. Of course I'm just driving my first laps with them but you can see the oversteer is much more violent and frequent using the super fronts. With normal fronts it still oversteered at places where I didn't really think it should, but it also had pretty bad understeer. I've attatched the two replays for those interested.. Overall I get the feeling that the tyres lack 'bite'. They give up grip without a fight (i.e. a tiny little peak in grip) it seems, making the experience a bit 'floating' and not as 'tight' as I would imagine it to be.

You really get punished with understeer if you're on the gas too early with normal front tyres but I'm quite sure you're *really* punished, everywhere, using the super front tyres.. Perhaps worth a try to swap the front tyres and have a go? Needs much more slow in fast out but once you get used to it..

About the gear ratios, they are correct according to Antsa, but is the final drive as well? Then the engine max torque and max power rpm should be close to the real car as well for it to work in LFS.

Some things I think are not really known is how the LFS suspension geometry matches a 911. Perhaps real life camber and parallel steering are different. I think tuning those to match the LFS suspension could help quite a bit. Also the damping seems quite 'firm' but I really have no idea if that would be realistic or not..

All in all an interesting experiment! (and I want a porsche for real now..)

Yes I'm plugging my own setups.. Have a look at the 'new philosophy part 2' thread in the setups sub forum and enjoy LFS a lot more

Well what I mean is the amount of cogs on the cogwheels makes a 'big' difference.

a cog wheel transmission with 40 and 41 cogs is a step of 0.025. For a step of 0.001 to work you need one 1000 tooth cogwheel and a 1001 cog wheel which would have the diameter of a lorry tyre if the cogs need to be any bit strong

I don't really know how gears work but I bet you can't have 40/41 40/40 40/39 as the distance from center to center would be different so for one gear you might have something like this:

40/40 = 1.000
38/42 = 0.905
36/44 = 0.818
34/46 = 0.739

just as an example.

If only real cars could set gears in 0.001 steps.. Sadly the ratio of available cogs is much more limited. Its one of those small things that I'm just mentioning just in case its not on the long 'to do' list yet

added a GT turbo setup and updated the fz50 setup in the first post. Here are some replays of certainly not really good driving but its the kind of above average (uh?) track day guy doing some laps not really knowing the car or the track that well..

Hmm I think that you are 'over driving' a bit. With the LX4 I can't get the front tyres to their alledged optimum temp (stuck at about 40c, optimum being 50c). The rears hover somewhere around 60c. With the Fz50 I recall (its been a day.. lol..) front and rear to be near optimum, perhaps a few degs too warm.

Just about any (I'm quite sure *all*) setups with super front tyres are *so* lacking understeer that a lot of LFS racers have become used to a very unrealistic and most of all unsafe handling car. When people complain about understeer in cars, they are often simply not driving the car the right way. Mostly entering turns too fast causes understeer. Without a LOT of power you can't always get rid of that, especially in faster corners in 3rd/4th gear. I believe this is fairly realistic as in these gears you don't have enough power to make the rears loose grip so your high corner entry speed will be punished with understeering as the corner is too tight for the speed you're travelling at.

Most LFS car setups you can dial in oversteer at any point. Even just cruising in 3rd gear half throttle can result in a spin which is so far from reality that my setups are a bit of a shock as they are so different, and I hope a lot more realistic. I'll upload a couple of replays after breakfast to give some idea.

After a few hours of tweaking and lots of fun I more or less completed a new setup for the lx4 and fz50.

Short intro to those who haven't tried my original 'new philosophy' pack, here is the trick:
- normal fronts
- super rears

This time I've changed a few things:
- springs based on weight distribution of car + fuel + driver (does wonders for general neutral feel)
- dampers also evened out based on this rule for balanced damping
- added stiffer rollbars

The goal of the first setup pack made ages ago was to show that 'oversteer anywhere' didn't have to be the case with LFS. The result was sort of overly safe handling cars, a tad too extreme. I also didn't realize that having 16 front and 2 rear rollbar is indeed a factor of 8, but their stiffness isn't really enough to do a lot compared to what the springs do, so their effect became a lot more noticable when I upped their values.

Again, IMHO these setups transform the handling of LFS from 'obviously way too unsafe and oversteery' to 'might actually drive the car in real life without too much fear of dying'.. But you can play with the cars a bit. I wanted to:
- not have major lift off oversteer / spinning
- unless you scandinavian flick unsettle the car
- not have power oversteer
- unless again steering violently or
- being aggressive in 1st or 2nd gear.

When you drive smoothly and within the limit you'll notice that the cars really don't bite whereas with most setups you will spin way before you reach what you think is the limit of grip.

I might make more setups but for now here are the ones for the Fz50 and lx4, aptly named 'safe2006'

I hope you enjoy them, my first pack got more than 600 downloads and positive feedback at RSC so I think they're worth a serious try. Laptimes are not on my mind, they will probably be slower due to normal instead of 'death wish' front grip. I want to make LFS more realistic and that is what - I hope many will agree - these setups do!

Edit: I use a 900 degrees turning wheel so I use maximum steering lock. Since you don't have to use a lot of lock to catch the mild slides these setups might develop I *urge* people without a DFP wheel to lower the value. Really you can use 12 degrees of steering lock on a 'single turn or less' wheel.

Edit jan 9: XR GT turbo added, Fz50 changed... but I think I'm mixing two setups up now so stay tuned for the 'real' new one for that soon..

Last edited by Niels Heusinkveld, Mon 9 Jan 2006, 01:28.

yes its dark but you can see the wheel, screen, and pedals being pressed.. Thats all you need really!

Some might have seen my alternate setup pack which puts normal front tyres on all the RWD cars and super rear tyres. Combined with safe differentials, rollbars and springs, this makes LFS RWD cars not oversteer automatically. The rear weight bias of the FZ50 makes oversteer still quite possible but you have to throw / be rude to the car a little bit.

Not that easy with 720degs of lock and trying to heel & toe! But entertaining

I had those artifacts when my geforce 4 overheated, but it could be a driver thing as well..

In all honesty it does seem that LFS currently does have a rather big grip dropoff with temperature that I doubt is there in reality, edit, or they heat up too fast..


I also think drifting is rather pointless, but its a nice test of 'extremes' and the tyre model should cope with it well, making it an acceptable thing to try and do in LFS imo

I'm no expert on drifting but it seems I can heat the rear tyres of the fz50 in less than a lap to the point where they have no grip at all which I doubt is totally realistic. Edit: The few drift video's i've seen seem to last more than one lap with no real change in car behaviour.

Last edited by Niels Heusinkveld, Thu 29 Dec 2005, 21:31.