I also find that some tracks are simply horrible to drive on. Especially when they use ISI trademark sine wave bumps. I modified my terrain.tdf so these crappy unrealistic bumps are turned off. On tracks that have their own tdf, I tend to turn hem off as well.

Also, some tracks have ''grip zones'', often overdone. Then there are many tracks that simply don't have proper transitions in road camber..

The difference is staggering between a bad and a good track, not just in the 'nature' of the track. At the Ring for example you bounce all over the place over the sine wave bumps and big polygons. At Barcelona you have aaaaaaaaaaages to slowly smoothly drive it..

At the moment I love Road Atlanta by Uzzi. Snetterton 06 is alright, though some parts have a deliberatly 'gripless' outside of corners.

Good tracks in rFactor are few and far between.

Quote from Hyperactive :

Not big fan of offline racing but so far I kinda like this car. Although I had to buy rfactor to try this I don't regret this at all. Although I must say that the car feels a bit too easy to drive; it kinda oversteers in a way that is always very controllable and understeers only when you know it is going to understeer.

http://www.edmunds.com/insidel ... cleId=103666/pageId=61310
http://en.wikipedia.org/wiki/Chevrolet_Corvette

Sorry, gtg, I'll finish this post later...

Very happy to read that actually! rFactor being easy and predictable? Many LFSers won't believe that ;-)

Hey Kompa, glad you like it..

Those stutters.. I don't know .. we haven't had reports about that. There aren't many VISTA users probably so I wouldn't rule some odd OS / rFactor compatibility / driver isseu out..

What about directx7 mode, just to see if lots of fps helps?

We didn't ''do'' damage in this mod, online with damage enabled, it breaks all the time..

We even managed to blow an engine with mechanical failures turned off.....

Editing the tyres is far too difficult as the model itself just doesn't guarantee results.. You really have to feed it well.. plus the rest of the car has to be correct as well.. I get some masochistic pleasure from it nowadays..

BTW, don't forget that there are no less than 3 choices of rubber for the corvette, from 'not so good' (though not bad!) 0.89G on the skidpad to 0.98 to 1.07..

Basically you get 3 cars hehe

Quote from Ian.H :

JT: Yup, using a DFP (set at 720 degrees). I will grab the realfeel plugin at some point as I plan to add some config settings for it to an update of rF Ignition at some point but had given up with rF before it was released.

I did notice that if you shift the weight around in the corner, you can definitely use your right foot to steer it and keep it there in a smooth powerslide too (but there's a limit that can be reached.. as expected.. but it feels a _LOT_ better than most other rF mods in this respect, which most seem to suffer the age old F1C issue of "more than 10 degrees and kiss ya arse goodbye!" syndrome).

I only did maybe 20 laps and the track's pretty tight and 1.3miles long and as I say, not touched rF in ages (actually not played any racing game for a couple of months) so I suspect I need to get used to things again. That said, it didn't feel "horrible".. I guess I was expecting a little more front end bite, even from a road car.. but then again, it's a Vette.. and getting US cars to corner is like getting blood from a stone


Niels: I'll try some more and a few other tracks (only ISI addon track I have is Silverstone) and will have a gander at the realfeel plugin sometime too (and adjust the sound stuff in the PLR file). 60fps is just a dream however, I get on average nearer 30-40, 20 at the back of a grid with 11 AI, 6 cars visible.. my FX5900XT don't cut it for much more than that, but it still seemed fine to drive (maybe I just got used to lower FPS over the time).

I didn't change the setup much, just the fuel.. so I'd need to give it a proper test really, the above was my first initial thoughts. I do prefer street cars to GTR style cars too, so this could be fun.. shame the AI is a pittance in rF as I don't play it online


ajp: Track's 'Ashtown Park'.. my first attempt at track building built about a year ago, but never completed it how I wanted it to be so never publicly released it.



Regards,

Ian

Morning Ian,

Those framerates are killin ya! What about dx7 mode, no AI cars? Plus did you do the 'frames rendered ahead=0' trick (using RivaTuner)? If you that and manage to get the fps up to 60+, it becomes quite a different experience.

I've said enough about how I feel about the DFP.. I...umm dislike it. I would not calibrate more than about 450 degrees with it, just to make its internal resistance 'acceptable'.

Glad you agree its better than most though, I always post at the LFS forum because.. if an LFS player likes an rFactor car, something must be quite good somewhere..

Slooooooow in.. fast out.. find your turning point, wait a while.. and find your throttle application point, and you can drive it on the power out of any turn.

You can't turn the wheel and expect the car to turn of course Slow with the inputs, nothing too sudden.. not too fast into the corners and a lot of patience.. then I hope it'll get better. Boring as it may be, ISI packed Barcelona with the game, which is fairly well modelled. See if you can get your times to a steady 2:08 using the 'stock' tyres.

And yes, get 1.250, some things improved there! (and apply the readme PLR file sound settings, and in general make sure you get like 60+fps all the time)

Did you make those vids you mentioned?

Quote from spankmeyer :

Could you please elaborate a bit, never heard of such settings. Are those settings some kind of rFactor-made-up-physics-thingies-to-make-it-somewhat-feel-right or real world suspension geometry fundamendals? Fast-bump dampers? Fast-bump damper threshold?

This was not a troll, by the way.

Anti dive is the tilting of the upper wishbone..


purely physical, very much real and very much often used to some extend on real cars

Dampers are not uncommonly 'low' and 'high' speed. Very common in racing and probably somewhat used in road cars as well.. not sure.. Its simply the speed at which the damper moves. Below a certain speed damping x is used and above this speed damping y is used. suspension movement 'speed' at which this changes is the threshold.

rFactor does more suspension thingies than LFS at the moment, full 3D.. so you get bump toe, dynamic roll centre movements, dynamic roll camber rates, scrub.. the lot..

Quote from Bob Smith :

I don't have rFactor to try out your car Niels but:


Is that a case of changing locking factors/what we have in LFS setups, or something different?


Well I have to say, two things completely missing in LFS (to my knowledge). How much difference have those changes alone made?

It changes the lock % (though this car has basically a locked diff looking at wheelspeed differences from 40% lock) and also a 'pump' setting, the part of the diff that increases lock toruqe as wheelspeed difference increases.

Anti dive is important. Real wheelrates of performance cars are still low! 1.2hz is not uncommon. A beemer M3 has aparantly 18000N/m front wheelrates. The Vette has 22500N/m. Without antidive you are in serious trouble with a normal centre of gravity height of about 50cm, it'll dive onto the bumpstops. Without anti squat and anti dive, I simply could not work with the real wheelrate data.

Anti squat also helps the rear end drop with low wheelrates.. I use some 15 .. 20%, which is 'guessed' though compared to videos it seems to be ok now.

In many ways like full 3D suspensions, rFactor isn't as simple physics wise as many people think.

Edit: and now even the tyres don't suck anymore!

count me in for a good pitchfork showing

Hi lads,

Corvette C6 2.0 is out, this time physics have improved a lot:
- roll 'bug' fixed (much less body roll, calculations match result)
- better diff, it was 'too locked too soon' smoother more progressive feel
- three tyre types, 0.89, 0.98 (std) and 1.07 skidpad G
- real wheelrates
- proper anti dive / anti squat geometry
- more..

I still think its an rFactor car anyone who owns the game should try.

*read the readme* though! you need a few settings (PLR sound settings) to really make it work..

Those interested, make sure you spend some time driving it with a 'well running' rFactor. As long as you're sure you've disabled all the driving aids, get high fps and run 'render ahead' to zero, you get a quick responding smooth game. The supplied Player file will help you with some of those things..

end of off topic.. :0

/niels

http://rapidshare.com/files/51444754/corvette_c6_v2.rar.html

Quote from JeeP :

http://nl.youtube.com/watch?v=-xb7FaId1gQ



some racing from last week

Bad hands on wheel technique! Give me a BMW and an empty Zandvoort!

Nearly choked hahahahahah

Not for Norwegians!

Here is how the new 'poor' tyre 'upgrade' drives, 0.88G on the skidpad but they're a bit flexible and suffer from load.

http://www.youtube.com/watch?v=0rq4ovijurM

I do have *some* money

Over here they tend to try and sell them for near 100 euro which is a bit much, but I made some (lower) offers. 75 would already be pretty steep, so I think along the lines of about 50 euro, though that may be optimistic..


Edit: Been very lucky to find a local guy put his 6800gt on an auction site. No shipping costs, and no further delays, so i'm back in 3D land already! (until I try to mount the cooler again? )

Last edited by Niels Heusinkveld, Wed, 25 Jul 2007 21:12.

Heya lads,

Looking for one of these, so if you have one laying around and willing to let go of it for not too extreme cash, I'd be happy to hear from ya!

/Niels

The sad story: I bought a new cooler for my 6800GT, the old one was hard to take off but I managed well, or so it seemed.. after about 10 mins the card gave me all sorts of purple thingies, odd 'blocks' in screen, anywhere from the bios to windows, it also failed to go in windows screen mode..

Work on the new version continues, tyres are made more around 'rules' (i.e. simple maths on the thread width / sidewall height to get load sensitivity / peak slip / peak slip change with load etc).. which seems to work well.. Elsewhere on this forum I was shown a big inertia database that seemed to imply that the inertias where too low, which is good news, if you can make them higher the car will become easier and 'slower' in response, helping yaw and roll behaviour, while seemingly being more realistic just looking at the numbers..

Been long enough for a new vid..

PS notice it is topless now.. though for those who don't like nudity, the topped version is still available..

Quote from BuddhaBing :

Speaking of which, Niels, how confident are you about the moments of inertia you've derived for the C6? The reason I ask is that I've been looking at the NHTSA (National Highway Traffic Safety Administration) inertia database (http://www-nrd.nhtsa.dot.gov/v ... ertia_database_metric.pdf) and the MOIs that you're using for the C6 look to be on the low side. They're even lower than the MOIs for a 1998 Dodge Neon, which is a much smaller and lighter car. The Neon weighs 12199N (1244kg) and has MOIs of (1748, 441, 1945) kg-m^2 in the pitch, roll and yaw axes respectively. Your C6, according to the HDV, weighs 14926N (1522kg) and has MOIs of (1650,395,1942) kg-m^2.

Heya,

Thats a good find. I had this but didn't see any inertia numbers in there... Scrolling down a few pages helps..

Providing they tested it correctly, which seems to be a fair assumption, yep, my thoughts of using a solid box + the unsprung weights results in inertias that are a bit too low most likely. Thats really good news, the roll behaviour and yaw will become 'easier' making it, if possible, even more LFS like in some ways..

BBT, I prefer ''my'' corvette for rFactor (it has improved since the release) over anything in LFS, not just because I tweaked it until I liked it, I tried to use realish numbers for everything. Therefor I think rFactor is better.. well.. one car..

And the danger about those grip curves remains that in reality you always have a few of the tyres in a combined longitudinal / lateral slip combination. This is aparantly easy to do wrongish in sims. Looking at base curves used in a game doesn't have to say a lot; Todd also mentioned the variation one gets with drum test rigs and 'flat' surface test rigs when real data came up.

Its all just a bit daunting!

rFactor is better.


damn..

I'm serious too.. However, thats only with good numbers entered, who knows how LFS would feel if some numbers improved..

Hard to know if you're judging the physics engine or the numbers entered

That is a big thing; you're not 'riding on the curves', because the result on the road is often a combination of longitudinal and lateral slip. If you have real curves, measured perfectly, and you enter those curves in a sim, the output will only be perfect if the force combining is perfect as well. Since, aparantly (Todd said... ) force combining is tricky and easy to do slightly wrong, likely seen in LFS and ISI, the whole point of realistic curves in sims sort of stops being all that important! The target is not 'real curves', the target is 'exact final force vector'. So I am saying, even if you would find that curves drop a lot after the peak, copying that curve to a sim won't necissarily make it more realistic if the force combining isn't perfect!

I've been spending too much time with rFactor and only when you get to the nitty gritty of it you tend to get some appreciation how changes in the curves (god knows how they are combined), lead to changes in car handling. With the released corvette, sustaining a high angle powerslide is a little nervous; seemingly lateral grip isn't as dependable as I'd like. I've since only slightly changed the shape of the curve. At a slip angle of 26 degrees, the new curve has 1% more lateral grip. Hardly spectacular, but this made a noticable change in the handling; more confidence in keeping the back stepped out at a big angle. Given the likely inaccuracies in force combining, a completely flat curve after it reaches its maximum would probably be a simplification one could defend in court..

Longitudinally I've never really been sure what is going on. Its common knowledge that you can screw up your 1/4 mile time if you don't launch smoothly. The conclusion is that excess wheelspin must mean a reduction in grip, which could VERY well be the case. Thinking on the matter though, say you're doing a drag run, with ''knowledge'' in the back of your mind that wheelspin is bad. When you hear / see the wheelspin, what do you do? Get off the gas to try and stop them from spinning... So where does the lost time come from, the spinning tyres or the gas pedal not being pressed for a few tenths of a second! Not saying this is true, but its worth considering at the very least!

Another longitudinal ''thing'' that I can imagine is the excess heat generated by noticable wheelspin. When smoke comes from tyres, I can imagine the composition of the rubber is sort of fluid and mushy right at the surface of the tyre. This might reduce available grip somewhat, though the extend is open to debate. If you would find data up to high slip ratio, and it would show a drop off to, say, 80% grip at 1.5x slip, this would already include the effect of the rubber heating up. It seems that most sims use base curves and, on top of that, add temperature effects, reducing grip further. Here also, force combining is what makes the driving experience, so some amount of simplification might well be justified.

Attached the current grip curves for the Corvette, plus a comparison (that 1% difference at 26 degrees slip) that you can barely see, yet do notice when driving, of the new curve and the one that is in the Version 1 release of that car.

So in semi conclusion, speaking about tyre curves and how much they drop off tends to assume the force combining is 'perfect' which it probably is not. Secondly, you can't see how the handling will be affected by different amounts of lateral dropoff; you can't predict how a drop to 80% feels just by looking at the graph. From my limited but practical (rFactor that is) experience, 1% difference in grip at a big slide angle of 26 degrees makes a noticable difference. My slightly premature conclusion would be that any tyre that drops noticably towards, say, 30 degrees slip angle, will be VERY hard to drive beyond the limit, unlike what you see so many real drivers do in real (road) cars.


PS: once again, a really informative thread about cars / physics; LFSforum - respect!

One of those things I used to find about rFactor is how little tye tyres communicate with sound. Especially with GTR you'd hear that dreaded bad loop of a 'skid sound', almost regardless of the magnitude of your 'slide'.

I looked for a way to really make the tyres sound different from slight scrub to peak grip, but then still increasing in noise and pitch a LOT beyond this peak grip. A maniac slide or locked tyre tends to make a lot more noise than driving at the peak, yet I never really heard that in ISI!

Until more random parameters got tweaked and sounds edited!

Preview attached, its not about the absolute sound quality of the skid, but more to show the bigger dynamic range of tyre sounds.. notice the mistake at ~30secs (big slide) and the locked tyre at ~1:30 (not too pretty).. and the intentional sliding after 1:40..

Very early days, but chuffed I am for sure. If you look at rFactor as an unpolished early Beta version its not too bad!

CarFactory makes suspensions with certain characteristics that you enter:
- roll centre (and how much it moves about)
- roll camber rate
- travel..
- ackerman
- anti dive

and it just makes a geometry that has these properties. Since its just a sim and there are no physical bits getting in eachothers way, you might end up with long A arms that would in a real car, be mounted in the middle of the engine..... Luckily space is no problem for a sim..

Thanks! Glad to see the 'ultimate test' turn out ok: LFS players on rFactor tends to be a sure 'miss' If LFS players find an rFactor car drivable, its a good sign!

I have no force feedback so I have no idea how that feels, I hoped it would be as good as rFactor can do with realfeel. The TBC file has an 'pneumatictrail' value, you can play with that to change the FF, and of course the main realfeel ini settings play a big role..