I think the point he was getting at was the fact that you can crank the steering to full lock, and there is actually hardly any understeer or even oversteer. It is so neutral and so stable. Driving the track normally, it is very possible to just do full-lock turns and you will be just fine.

If you crank your wheel at 90 degrees, of course you won't get oversteer from that, like on this skidpad, but I think it is very hard to create any oversteer with the little 1600 unless you have some uneven surface or just do some wild control behaviour. If you mount the rain tires (or whatever those RG tires are), try the car with those. To an extent, those feels kind of nice, and have a bit more possibility of sliding. They still have grip, but they are loose for pushing it faster (but those tires have lower grip levels anyways, so oh well).

EDIT: Doh, some words for understeer, I meant to say oversteer.

And if we really want to talk tires, maybe wait till this new LFS patch too.

Quote from jtw62074 :

Why do so many people perpetually insist this behavior is impossible?

for one its based on experience (havent doen any slides like that in a real car yet but ive done plenty with rc cars on all sorts of tyres) and with time you get a feel for what a car can do and what it cant possibly do
and its also that kunos mentions that you can feel the 3 stages of his tyre model (grip ... slipping at the edge ... and sliding) and somebody here voiced his concerns that it sounds like the model switches between those stages instead of a smoother more realistic transition which incidently is exactly what it feels like

Quote :

If you have more rear grip than the front this is indeed what will happen provided you don't yaw the car so quickly it doesn't get a chance to straighten back up.

the problems begin with the way you enter that slide ... you step on the gas pedal and the tail starts to overtake the front ... so far so good ... but once the tails stars to step out the car instantly snaps (so much for not yawing quickly) to a full 90 and stays there
but it gets worse ... the usual reaction to this is lifting your foot from the loud pedal and countersteering ... the result of this is that the car instantly turns a 180° and you find yourself still sliding perpendicular to the track but facing the other way this time

RC Cars, lmao.

you do realise that im replying to someone whos afaik using essential the same tyre physics code for a rc car simd and a "real" car simd and that in the real world pyhics are the same for all cars regardless of the size dont you ?

I don't see how an R/C car and real car tire can compare. Maybe Todd can explain that, but I find it very hard to believe they are the same. A pebble or dimple is about the equivalent of a pothole or tree log. And to have the car weigh in to about the weight of your floorpanel carpet, quite a lot differs... in huge ways.... especially if you have experience through 'feeling' the car though remote control :zombie:

Quote from Shotglass :

you do realise that im replying to someone whos afaik using essential the same tyre physics code for a rc car simd and a "real" car simd and that in the real world pyhics are the same for all cars regardless of the size dont you ?

Um... no not really, considering the tyres are completely different in design.

The "lack of sound" feedback when pushing to the limit or blocking tires may perhaps be accurate, BUT I think they developers forgot that this is a sim - We can't feel how the car is behaving, so ultimatly I would say we are being handicapped.

I've driven several laps in nK - actually so many that I did the lamest laptimes in LFS last night, as I my mind was geared toward the nK gearbox

But still, every lap in nK it was like I was doing it the for the first time - I couldn't figure out the limits of the tires, especially on the braking zones - I found it to be very difficult to sence if I was braking on limit or actually blocking Sometimes the car would turn itself slightly - I guess I was blocking the tires since it did that.

The dev's could have implemented some FFB reaction so you could sense the tires more clearly.

I've never driven a Formula Ford, so I can't tell what thats like (or how the F1600 is more or less supposed to be like), but unless someone corrects me, I find it hard to believe that you can't feel the grip level of the tires.

There is ONLY sound and no feedback on the wheel - it does get harder to turn when ur in a curve, but other than that it actually feel like ur on a silky smooth road, especially in the turns.

I can feel the road - ie. the bumps, the curbs - flatspots are the only tire related effect I can feel, but other than that it just feels wrong to me.

The FFB is defenatly better on some areas when compared to LFS - I find it to be more crisp, but in LFS, you get the sence of the tires more clearly, wich in my openion is more important than feeling bumps and curbs.

Am I making any sence here?

Quote from r4ptor :

Am I making any sence here?

Yeah, somewhat, but I don't know what game you are talking about in some parts

Quote from Tweaker :

Yeah, somewhat, but I don't know what game you are talking about in some parts

The thread is about netKar Pro and LFS - I'm talking about those two.

Yeah, I know, I know.. only wrote nK instead of nK PRO, but figured it would be obvious

No no, I meant some sentances... I don't know what game they apply too.

Quote from Tweaker :

I think the point he was getting at was the fact that you can crank the steering to full lock, and there is actually hardly any understeer or even oversteer. It is so neutral and so stable. Driving the track normally, it is very possible to just do full-lock turns and you will be just fine.

Ok, I must have misunderstood. Still, this is isn't necessarily wrong. Really depends on the wheelbase/cg height ratio. If it's greater than a certain value then you'll start to get understeer at some point. If it's lower than that you can very well continue more towards oversteer as you increase steering lock (to a point of course, as you said, approaching 90 degrees isn't going to do it.)

As long as the tire data and model, plus the mechanical stuff on the car is right, the behavior should be correct. I haven't played much with the setup in nKPro yet so haven't really examined anything too closely.

My point really was that if you get a real car to some huge sliding angle, then neutralize the steering and release the throttle, it is entirely possible that the car will straighten up. You can really design a car to do more or less what you want it to do, so just because that behavior exists in one sim and not in another (of two different cars and sets of tires), doesn't mean one of them is wrong.

Quote from Tweaker :

If you crank your wheel at 90 degrees, of course you won't get oversteer from that, like on this skidpad, but I think it is very hard to create any oversteer with the little 1600 unless you have some uneven surface or just do some wild control behaviour. If you mount the rain tires (or whatever those RG tires are), try the car with those. To an extent, those feels kind of nice, and have a bit more possibility of sliding. They still have grip, but they are loose for pushing it faster (but those tires have lower grip levels anyways, so oh well).

EDIT: Doh, some words for understeer, I meant to say oversteer.

And if we really want to talk tires, maybe wait till this new LFS patch too.

I haven't tried switching tires yet. Will give that a go. Thanks for the tip.

Quote from Tweaker :

I don't see how an R/C car and real car tire can compare. Maybe Todd can explain that, but I find it very hard to believe they are the same. A pebble or dimple is about the equivalent of a pothole or tree log. And to have the car weigh in to about the weight of your floorpanel carpet, quite a lot differs... in huge ways.... especially if you have experience through 'feeling' the car though remote control :zombie:

Assuming a clean surface, of course: We've actually been testing foam RC tires on a machine for quite awhile now in order to find out what the lateral force vs. slip angle curves look like for different sizes and durometer readings, and indeed they're quite similar to full sized, air filled, rubber tires. The cornering stiffness is a lot lower (peaks are at very high slip angles), but the curves look the same overall. So really you can model these RC car tires with the same model you use for big cars. Just change a few parameters here and there and off you go.

Granted, this was not done on a carpet surface with electric tires, although we may do that in the future too. I expect them to look pretty similar. It's really just about finding what slip angle the peak is at as well as overall grip as a function of load so you have load sensitivity. All tires look pretty much the same in that regard, even the tiny little ones

Quote from Shotglass :

for one its based on experience (havent doen any slides like that in a real car yet but ive done plenty with rc cars on all sorts of tyres) and with time you get a feel for what a car can do and what it cant possibly do
and its also that kunos mentions that you can feel the 3 stages of his tyre model (grip ... slipping at the edge ... and sliding) and somebody here voiced his concerns that it sounds like the model switches between those stages instead of a smoother more realistic transition which incidently is exactly what it feels like

I wouldn't worry too much about how the transition occurs. Stefano has had a lot of experience with tire models. I'd bet it transitions just fine. Isn't he using a Pacejka model?

Quote from Shotglass :

the problems begin with the way you enter that slide ... you step on the gas pedal and the tail starts to overtake the front ... so far so good ... but once the tails stars to step out the car instantly snaps (so much for not yawing quickly) to a full 90 and stays there
but it gets worse ... the usual reaction to this is lifting your foot from the loud pedal and countersteering ... the result of this is that the car instantly turns a 180° and you find yourself still sliding perpendicular to the track but facing the other way this time

Oh, ok. I haven't tried that in nKPro as I'm usually driving pretty nicely without a lot of sliding around. However, if something sudden happens right around 90 degrees that could indeed be a bug. I've had problems with that in the past too. Took awhile to figure out what was wrong and fix it though. I'll give it a try and see if it feels like mine did.

Granted, don't get too upset about that. As long as you're driving in the normal range or just a bit over that, a bug like I had really doesn't effect the handling at all. I.e., everything's just fine until you really get the back end waaaay out. It's a bit like low speed models where a car will float around a bit when it's supposed to be sitting still, or slide slowly down a hill even with the wheels locked. It doesn't effect the realism at all once you're going more than a foot per second or whatever (some very, very low speed). Lots of professional vehicle models used in engineering research have had this same problem. Many folks just ignore it because they don't really care what happens at anything less than typical driving or racing speeds.

Quote from joshdifabio :

Um... no not really, considering the tyres are completely different in design.

no theyre not
rc car tyres are rubber tyres with somewhat stiff sidewalls and a foam filling that gives the whole tyre about the stiffness a real cars tyre would have scaled down ... theres no reason why rc tyres shoudl behave completely different from real ones
and considering todds post the same holds even for cellular rubber tyres
of course there will be differences in how the tyres react to bending sidewalls (especially on cellular rubber tyres) but for one afaik lfs is still the only game that simulates sidewalls at all and the effects of this shouldnt lead to entirely different behaviours
so what i gather from todds testing is that any piece of rubber you press on a strip of tarmac will behave more or less the same regardless of its size

Quote from jtw62074 :

I wouldn't worry too much about how the transition occurs. Stefano has had a lot of experience with tire models. I'd bet it transitions just fine. Isn't he using a Pacejka model?

the transitions feel very dodgy to me though ... they happen extremely suddenly ans violently and there is nothing in the ffb sound whatever that tells me when im close to the edge

Quote :

Oh, ok. I haven't tried that in nKPro as I'm usually driving pretty nicely without a lot of sliding around.

dont take me too literal on what ive described though i have exagerated a bit but the way it happens gives you the feeling i tried to convey
and it happens to me while racing one moment i have the driving on rails feel next second i find myself very sideways wondering what the hell happened

hey wait a min , what's that RC thing you're talkin about ? is it a sim ?? if yes , how come i've never heard about it ? is it somethin like LFS ? and most importantly , is it realistic ? anyone's tried it here ?

You mean Todds RC sim?

is he trying to be ironic or is he really just uninformed ?

Quote from silent_wind :

hey wait a min , what's that RC thing you're talkin about ? is it a sim ?? if yes , how come i've never heard about it ? is it somethin like LFS ? and most importantly , is it realistic ? anyone's tried it here ?

http://www.virtualrc.com/

Like it says in the man's sig.

It is very realistic apparently, although I admit when I tried it, i couldnt tell whether it was running at ten times speed, or the cars are just insanely fast. Probably the latter, but its extremely hard to keep the cars on track as you need reactions like a ninja.

Quote from colcob :

It is very realistic apparently, although I admit when I tried it, i couldnt tell whether it was running at ten times speed, or the cars are just insanely fast. Probably the latter, but its extremely hard to keep the cars on track as you need reactions like a ninja.

well just assume those tracks are also to scale (and they more or less are)
so you have a 1:8 car on a 1:8 track going at about 140kmh down the straights

there was (maybe still is) some weird butg though that somtimes makes my car actually go at many times its normal speed and warp too for a while until all return back to normal (looks like im watching myself lag)

but either way rc is short for radio controlled so its not a sim its real cars scaled down

Quote from Shotglass :

but either way rc is short for radio controlled so its not a sim its real cars scaled down

Real cars scaled down?

Lol those buggers are hard to control with the keyboard. Digital input doesn't seem to suit this one but it's kinda fun in the end..

Quote from Tweaker :

Real cars scaled down?

tyres behave similar ... suspensions are mostly double wishbone ones and the dampers also work the same as in a car (only one way adjustable though)
technically they are very similar to real cars and therefore behave similar (you could say better than real cars as their grip level and cog and so on i vastly better than in real cars)

On VRC, indeed it's a real challenge with the keyboard and most people are really put off by it immediately without a proper controller. You couldn't run the real cars with a keyboard either, it'd be just as hard as in the game really.

On the real RC engineering level things are actually quite high tech. VRC was done in colllaboration with Serpent, one of the manufacturers (Pieter Bervoets, the founder of Serpent, is the owner of VRC), so I spent a lot of time talking with the engineers, Michael Salven and Rene Cornella (I stayed at Rene's place for about 6 weeks once). When Michael was designing their F-1 car (RC version of course), he had his CAD file open when I walked in to his office one day. I thought it was a real F-1 car on screen there. Nope, he had modelled the RC version after a real one and they were working on the prototype right then. Was very cool to see

Anyway, the vehicle dynamics of RC and big cars are the same really. It's just the numbers you plug into the model for weights and so forth that are different for the most part. The drivetrains are different of course though and there are some slight design differences, but all in all it's the same thing as a big car. Tires are similar in that force is a function of slip angle/ratio/load/etc. (just like any deformable body rolling on a hard surface), so again, you can use the same model there, but with different inputs.

Either way, I'm enjoying NkPro, and am also really looking forward to seeing the new tire improvements Scawen has come up with for LFS soon! These are sharp guys here on this LFS project and I'm enjoying watching them continue to improve this. Things can only get better and better, so let's just keep on supporting them. I think with all the time I've spent on LFS it's probably cost me only a few pennies per hour of entertainment. Well worth it!

@jtw62074:
Is that a VRC review or did you really want to say anything specific about nkPro?

Vain

I actually did post some stuff about NKPro, but changed my mind and deleted it. I'll move along now