Karts - Steering range and spinning easily?

At it's most basic level rF2 FFB sends the steering shaft torque as calculated by the physics engine to the FFB wheel.

The first challenge in doing this is that the physics engine calculates the steering torque in Nm however the FFB output is sent via Microsoft's DirectInput which expects an incoming value between -10000 and 10000 to signify full force left and right, or vice versa. Which direction is which varies between devices.

So, somehow we need to convert between Nm and DirectInput units.

To do this we need to decide on a Nm value that will correspond to 'full force', or 10000 DirectInput units.

[Anybody familiar with rF1's RealFeel plugin will know this as MaxForceAtSteeringRack, or whatever we called it]

In rF2 this value is set in the vehicle's HDV with the parameter NominalMaxSteeringTorque.

At this most basic level, if we ignore all the various other parameters that can affect the final FFB output, we have a simple equation:

ForceOutput = (SteeringShaftTorque / NominalMaxSteeringTorque) * 10000

The Skip Barber has a NominalMaxSteeringTorque of 9.5Nm, so when the physics engine is calculating a steering torque of 9.5Nm we'll get 100% force output at our wheel (10000 DirectInput units):

ForceOutput = (9.5 / 9.5) * 10000 = 1 * 10000 = 10000

If the steering shaft torque was 4.75Nm we'd get a 50% force output (5000 DirectInput units):

ForceOutput = (4.75 / 9.5) * 10000 = 0.5 * 10000 = 5000

At it's most basic level that is that, there's not strictly any need to worry about any other parameters.

Assuming all vehicles have their NominalMaxSteeringTorque set correctly the above system will use the full range of our FFB wheels for every car, with the calculated steering shaft torque scaled linearly to our FFB wheels.

However, with the introduction of consumer level direct drive wheels there is a drawback with this approach.

Basically, no matter how much torque the sim is outputting if calculated torque hits NominalMaxSteeringTorque then FFB output will be 100%. In something like the Skip Barber, with it's 9.5Nm NominalMaxSteeringTorque, if the FFB wheel is capable of more than 9.5Nm then we will get whatever the wheel is capable of, there is nothing to limit it to 9.5Nm.

The solution? Steering Torque Capability (STC).

Steering Torque Capability is very simple, it defines how much torque the FFB output device is capable of.

If STC is larger than NominalMaxSteeringTorque then a slightly different equation is used:

ForceOutput = (NominalMaxSteeringTorque / STC) * (SteeringShaftTorque / NominalMaxSteeringTorque) * 10000

Let's say we have a wheel capable of 19Nm and we're driving the Skip Barber again, with it's NominalMaxSteeringTorque of 9.5Nm.

This time, with STC set to 19Nm, at a shaft torque of 9.5Nm we'll get:

ForceOutput = (9.5 / 19) * (9.5 / 9.5) * 10000 = 0.5 * 1 * 1000 = 5000

5000 is half the available DirectInput units, so we'll get 50% of our wheels output. Our wheel is capable of 19Nm, half of that is 9.5Nm - bingo, we have true 1:1 torque output at our wheel. When the calculated steering shaft torque hits 9.5Nm we'll get 9.5Nm at our wheel.

No magic, no controversy and maybe a little less misunderstanding now? One can only hope.

 

Marc, for whatever reason you seem unwilling to understand what others are saying to you. If you think through your own suggestions you will realise that what STC does is completely logical and in line with your wishes. The shortcomings are unavoidable and absolutely not unique to rF2.

*I don't think I can offer any more in the current loop of explaining what rF2 does and why, and you coming up with 'problems'. Unless TechAde can get things across to you better I think the better starting point is you tell us what you want, specifically (your wheel's max torque, how much torque you want from a car that produces up to 9.5Nm, how much you want from a car that produces 20+, etc) rather than a single line pie-in-the-sky wish that lacks detail, and once we get to something that's actually possible we can help explain the rF2 settings that will produce it.

 

You are the one who doesn't understand and has made misguided suggestions and claims that there are simple fixes for the complicated issues discussed here. These are issues people like TechAde have been working on since before rf2 was even released.

TechAde's explanation just confirms what I already told you. Are you still worrying about what I am saying or would you like to now explain how STC solves problems for people with toy wheels? And why playing around with input parameters of 250 Nm is somehow useful or helpful?

I understand exactly what's going on here and some if it I agree with and some of it I do not. But STC is more or less irrelevant to the topic (as TechAde hopefully just hammered home). I have been saying that too, all along. Others have introduced STC as some sort of solution or useful adjustment into this conversation. It would be helpful at this juncture if those people would chime-in and say, thanks TechAde, we understand now and will withdraw STC as an issue that has anything to do with the original point of this thread...sorry for the distraction. Then, maybe we can get back to relevant adjustments, settings and sim car design choices. Some of which we might agree on and some we won't.

 

Sorry, I thought the sarcasm in my comment was obvious.

 

This thread has been so derailed, it was supposed to be with helping with driving the kart

 

So I'll just ignore pretty much every question you've posted, because apparently you didn't care anyway. In hindsight I guess I should have realised.

STC fixes that. Perfectly proportioned.

It covers the whole FFB range, the max is just set too high. 3 of the 4 versions will be adjusted by ISI later, especially the road course config.

I told you, and if you took 5 mins to understand how STC works you'd understand why you felt no difference. Why do you think I tried 250? Because I would think that's a reasonable setting? No! Because it shows absolutely that it works in the way it does, and if you tried 250 you would also see. And if you tried 50. And if you tried 25 with the skip barber. But hey, let's not get bogged down in actually trying things...


Regarding TechAde, you gave him a +1 when he disagreed with using STM to help with the DW12 (I agree with him also, if you're curious), suggested he'd agreed with you about caster not having such a significant effect (it's not clear where he did... I asked, but you didn't answer), then you kept arguing the DW12 behaves incorrectly without supplying any sort of supporting evidence (I keep asking, but you ignore it and just attack one thing I've said that you don't understand).

Finally, after you show your continuing lack of understanding of STC TechAde comes in to try and explain it to you, and now you're putting your arm around him as supporting your argument. Whatever that is.

I really can't follow it.

And yeah, sorry about the OT.

 

just gonna put it out there that the latest update is the most realistic iv ever felt a kart drive in a sim to date

 

+1 Let's get back to the point.

 

Ok so can anybody help me? I only drove rentals with 13hp and u really had to tackle them to kick the rear out. And even then they were nice to handle at the limit. Steady slow corrections.

If I try this in rf2 an instand spin is garanteed.

So do I really need to be that sensible with it? So delcate? Just small increments of turn-correct-turn-correct?

If that's the case I thing I'm done with the karts. :-( I tried that for hours and I don't like it. It doesn't satisfy.

 

Well to me it feels okay, I even get what Z06Trackman wrote about. Getting the Kart on 3 wheels but then it just spins instantly. Maybe I'm getting old and my reflexes are gone. Haha. ;-) Would love to enjoy them, as I really like Karts in general.

 

Hmm. Well maybe yeah. Maybe there has to happen so much within those first 5 percent of steering that it ruins the drive-ability of the Karts. I wonder if there are people with the same problem but different wheels... At least on my end I have no possibility to prove this. Haha. Only have this one wheel and there is no setting around it. Although I use a linear curve in the Logitech profile 96% and raise the multiplier in rf2 to between x2 and x4....// I also tried a lot of other stuff, written in here, to get rid of the dead-zone.


Edit: Went back to 100% in the profiler and added 4% of STM in rF2 at a multiplier of x1 and it behaves a lot better. Steering feels way to light now.´

So I guess it is just the FFb wheel itself.

 

It all depends on setup as well. I drove Rental karts that were setup with some understeer, and they were hard to spin, but also have had rental karts that spin very easily. Also, I have done karting in racing karts, and to me the ISI karts feel pretty close (well, 'feel,' they look very simular to how I would expect them to react to input). What I think is the biggest difference is just the feel, you don't feel what the game is doing as soon as you would in real life, and that is the biggest difference. For example: I once was in a rental-kart race, and I hit my elbow against a metal bar protecting the engine, and I couldn't feel my right hand for almost two laps. Just with that loss of feeling the kart felt much harder to control, and I was sliding (slightly) more then the other laps, just because I was correcting a fraction later. So feeling and setup are very important aspects that might make the game feel difference then real-life experience.

EDIT :: But off course, improvements to the in-game karts can (and probably will) still be made

 

I don't know why the default setup in RF2 for both karts is setup for rain, they have seat struts in they have the side pod bars tight and a lot of caster I take out all seat stays loosen the side pod bars as much as possible and take out about 5 degrees of caster. If the steering is to light (which is totally possible) then put some caster back in it so you will have a better feeling of what the kart is doing, that's the only reason I think ISI put that much caster in it by default to give some feel back for what you don't have (your butt in the seat feeling what the kart is doing). Let me know if this helps.


Sent from my iPhone using Tapatalk

 

Correct, you can't get rid of the deadzone because G25/G27 uses dual FFB engines so they've set up deadzone in middle to prevent oscillation between the two engines. The issue is the wheel itself, G25 uses quite ancient FFB tech and the torque it outputs is weak compared to modern wheels, this hurts especially with the Karts as their steering resistance should be fairly strong.

 

It's way better now. Not that immersive but faster to drive. Thanks guys. Appreciate all the input. Thumbs up!

 

I would prefer to accept that the G25 is a good wheel, but not a great one (I used one for years, so I know it well). The ISI karts, at the default steering rack setting, need a very high quality, low or no deadzone wheel to feel good. My Fanatac CSW doesn't even qualify.

Instead of altering the fundamental FFB settings, which will likely have various deleterious effects, some of which you won't even know about, I would just widen the steering ratio to somewhere between 210 and 240 degrees. Probably start with 240 and then go down if it feels good. Unfortunately, you can't change the "use car" setting for only one vehicle because the UI doesn't (yet) support that.

Using a wider steering range (still very quick by car standards) will allow your wheel to not be stressed to the max. It won't cure the deadzone problem, but it will mask it a bit. You can then go back to default forces where the kart will hopefully feel something like an actual kart (the steering will get a bit heavy when you are balancing on the edge through the corners, or, when you bind the drivetrain by turning sharply at low speeds).

Even on high-end wheels, the default super-sharp steering ratio is difficult to adjust to and the gives the wheels difficulty.

 

And I almost forgot: at least for me, without left-foot braking, these things are uncontrollable. I go so far as to re-map my clutch pedal to the brake so I can have a more kart-like stance. The ISI karts respond just like real karts maintaining better balance around corners with a certain amount of brake and throttle applied simultaneously.

 

Exactly. From F1 2002 to RF2 (although RF2 has improved on it more-so relative to any other ISI engine-to-engine update before it).

Still a blast though, but ya, those moments can become frustrating especially when you understand them. They stick out and are nothing like reality. And before the fanboys start, no, it has nothing to do with how good/bad/"accurate" the particular vehicle/mod is, car setup, your real-life wheel, FFB settings, what you ate for dinner, how good or bad of a driver you are, how much/little latency and input lag your PC and/or wheel has, the last insult your ex-girlfriend said to you, how much in-or-not-in the zone you were while you were playing, etc. etc. etc. It's a fundamental part of something/s in the physics engine going back almost 15 years now, i.e. it has nothing to do with the user or the user's inputs.

 

Lol I cant drive the karts to save my life. I just touch the throttle, I mean JUST TOUCH the throttle while exiting a curve, and the rear completely loses grip. then I apply 1 degree of countersteer, and the kart darts the other direction. They are impossible. I have driven karts in real life, and they are WAAAY easier to drive than these. I have a couple holes in my wall from trying to drive these things. Haha not really, but they make me extremely angry lol.

 

try these hints.


i had thesame problems initialluy.


http://isiforums.net/f/showthread.p...pinning-easily?p=361311&viewfull=1#post361311