That my post was more like a joke but if someone still happened to matter-of-factly mention lack of turbo modelling in some other context at the GTR2 forums, I'm sure he would get flamed by "I can hear the turbo sound!" posts and probably most of the players just simply refused to suspect it.
Lol, looks like so, 'turbo is sound, it is nothing else', what an odd way to think
I have asked long time that ISI would make turbo model into gmotor, there is no point to put turbo car in as it will never be anything like real turbo. Some say that you can do same effect with torque curve, but that is absolutely wrong statement, powercurve is WOT power, if you make it so that power comes at late rpm you are just creating engine that put out it's power at higher rpm, turbo lag is whole different thing, sure rpm affects it but it is not possible to emulate even a little by torque curve.
Currently LFS is only game that has turbo engines, others have only NA engines, of course there can be some title that is not known by me or that I don't remember yet.
But turbo modelling is coming to rFactor, next patch will contain rain, don't know if then there is turbo stuff too, perhaps not yet. Also too small tire load variables need to be sorted out, that is limiting too, big wheels or heavy cars are not possible currenly.
Yes you are right, there was gauge, but I'm not sure at all if there was correct behaviour, too long since I did play that to remember if it was just moving with rpm or did it actually have real turbo model behind it.
Many praise RBR to be most realistic sim etc. but I think it just give proper illusion of rally feeling, it has some oddities that make me very suspicious. Great fun it is however and very good feeling too.
I searched for former RBR devs posts at rscnet and BHMS forums, didn't find what I was exactly looking for but found this, not a from a dev though so might not be 100% true.
"RBR does proper turbo modelling, based on actual compressor maps. It calculates the exhaust gas rate in MFR (mass flow rate), based on load and RPM, then uses that information to calculate the manifold pressure (including boost pressure drop across the intercooler, lol!). From manifold pressure, you then get a direct reading for horsepower at the engine when combined with current RPM and engine load."
Hmm, if that is true it is very impressive, but for me at least it is bit difficult to believe that things are so complex in RBR, but maybe they are, I need sometime examine it better, but currently I have no possibility for this.
Edit: Seems that there is really no understanding how turbo works and what it affects to driving, no wonder GT4 like games are being praised as realistic.
From what I know, the turbo modeling is quite a bit more advanced in RBR than in LFS. Even the damage model incorporates the turbo, so if you damage one of the related parts the turbo pressure might be reduced or gone altogether.
Comparing RBR with LFS is probably a bit pointless, mostly because of the fundamental differences in gameplay. It's a bit "apples and oranges" in so many respects that a comparison thread would be difficult to keep on-track, so to speak. I've a great deal of admiration and appreciation for RBR, just as I have for LFS, but I can't see a way to align them so that a comparison can be drawn. Horses for courses, and LFS and RBR are very different beasts.
Well yeah, from the physics viewpoint yes, a comparison doesn't make much sense - but the turbo modeling doesn't exactly have much to do with rally or non-rally . Anyway, I agree, it's off topic so I'll not push in that direction any further.
Very true, however I think some aspects are similar, like how engine works. Of course it is possible to make it differently and still end up with same result, but I guess here we have two different results. RBR engine seem to take ages to drop down to idle for example, that is difference to LFS engine that I think is pretty well possible to compare and evaluate which feels more natural.
However comparing them as whole sim is going to be pointless indeed, with our limited hardware it is sure compromises are needed to make to get game running decent speed at cost of simulating some aspects. LFS and RBR has different compromises made.
But as I said earlier, it would need own thread. That might be however not very reasonable.
Don't get me wrong, if you wanna start the RBR vs LFS thread I'll do my best to participate! I just see it being a bit of a mutual appreciation society thread. On the occasions RBR has cropped up in conversations here before, I keep thinking I can hear wedding bells!
I'll continue this, this thread has had already so much unrelated stuff so why not...
This is one of the RBR issues... engine braking has nearly no effect at all, some say it's because anti-lag system in WRC cars is so effective but it is still very odd.
Yes, it might just mean the usual value tables but it's still obvious that it's more complex than the ISI approach, if you can even call it approach.
Generally speaking that's probably true. However, the internal construction of the tire has a huge influence over the cornering stiffness. One could build two tires of the same tread width, one low profile and one high, and depending on what was done with the cord angle(s) and materials, winding details, and so on, either one could have a higher cornering stiffness.
I know a guy that worked with the test data from the Firestone tread separation case years ago for the US government, and what he described happened to the cornering stiffness when you removed the tread was quite startling. The peak force didn't come in until an unbelievably high slip angle and the initial cornering stiffness was only 1/10th what it otherwise would be with the tread (and maybe the first couple layers of cords, I'm not sure exactly what they removed). So it's safe to say that the internal structure and build have a much larger influence on cornering stiffness than the actual sidewall height.
That being said though, I'd suspect that if you tested a whole bunch of tires you'd probably find that in general, the high profile ones have lower cornering stiffness just as you're saying. I've seen a comparison on a couple hundred bias/radial/cross ply cornering stiffnesses that were laid out in bell type curves on the same graph. The construction definitely had a larger impact on cornering stiffness than the dimensions did. That was probably by design to a large extent, so it's tough to say for sure just from that.
Formula one tires have this as well. The area between the sidewall and tread is so flexible that you can stomp the tires nearly flat. Paul Haney visited an F1 tire manufacturing facility and was surprised to see a bunch of guys doing that. That's just how they stored them.
Anyway, from what I read, the reason for that is likely for allowing the tread to remain flatter and in better contact with the road even when there is undesirable camber present, like under straight line braking when you have a few degrees camber because a passive suspension system just can't give perfect camber control in all situations. So it's a bit of a crutch. That would make sense with kart tires too as you guys run a lot of caster which is going to make some pretty serious camber at high steering angles, and not all of it is probably desirable.
Initial turn in bite, if you're thinking of the same thing I am from the 'behind the wheel' perspective, is likely the initial cornering stiffness, unless you're talking about steering to a large slip angle and then activating your butt-meter. The higher that initial cornering stiffness is the more turn in bite you'll feel. Granted, two tires could still peak at the same slip angle, but the shapes of the curves before that could still be quite different. This is probably what you're feeling as the difference between the two.
its just that the way i understood it is that as a rule of thumb a strong sidewall will cause a steep rise and a low peak angle
a low profile tyre basically has a very stiff sidewall with most of it being the rim and less of it being that impossible to simulate rubbery stuff we like to call tyres
What is real difference between table and realtime models from drivers point of view and is it possible to notice when table is enough large?
You can even make code to interpolate from table cell to another so you could have quite nearly same as realtime simulation, I just came to think about this and I think that there is not necessarily much difference, only thing is that you need lot of tables, some things are perhaps then easier to calculate real time, but mostly it should feel same, am I wrong?
I think for something like that, where the variables can be pre-calculated, then it's fine to use look up tables and interpolation. But when variables are unknown or changing a lot (e.g. the core aero physics in a flight sim, or the dynamic tyre behaviour in a car sim) then I'd much rather see real time generation of results.
It works for LFS and X-Plane, and is one of the main reasons why ISI and MSFS are lesser simulations in my book. For turbo modelling I'd have no problems with a sim using lookup tables.
the problem is the 'large enough' bit
when is a table large enough for the interpolation to work out
with a very large table you will approach the finesse of a forumla based system but eventually constant lookups interpolations and memory usage will grow larger than if you had used a forumla based approach in the first place
at that point you wont gain any cpu cycles to use for other parts of the sim and youll be stuck with an inherently flawed mathod that works just as good
of course if the code is well written it should be a no brainer to change the lookup method into a forumla based method (the weaving it into the current codebase not the actual working out the forumla and coding it bit)
also simulating different kinds of tyres/turbos/engines becomes a bitch with lookup tables ... think changing a few thousand matrix elements vs a few constants in a forumla
I'm certain that table based system will work for some things but of course more complex things require formulas.
You can calculate parameters to tables when you load car, so that wont be a problem, I believe.
Maybe there is some golden path with this.
As you know car ECU does contain fuel map, that is then interpolated and in some applications it is not interpolated, however you can't feel difference between cells, because those are enough close to each other to provide correct air/fuel mixture.
This is why I think that intake pressure could be for example in table based and that can be used for power output calculation or finding engine power from table so that there is map & rpm on y and x axis, values are then engine power, you can have WOT power curve where you can then calculate other values by formula. Turbo would then be multiplier, timer & TP table to get turbo spool timing.
In general that's probably true, even though it's not always the case. I suspect the cords have a much greater influence on cornering stiffness then the sidewalls do. Changing cord angles has a massive impact on the stiffness of the belts in different directions, much more so than anything you can probably do to the sidewall.
All else being equal though (cord angles, etc.), a low profile tire will indeed generally have a higher cornering stiffness as you said.
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