Wrong Russian fighters performance at high alts again

February 18, 2015

The Yak-1 goes around 580 km/h TAS at 4000 meters at standard atmosphere (assuming that the speed on the HUD is CAS and not IAS, i'm not sure about that, but the HUD speed differs from the in cockpit gauges). Nothing wrong with that imho, well inside 2% tolerance if you use the 571 km/h or 592 km/h figures that are floating around.

The problems starts above that altitude.

Exactly,we need to know whats going on with klimov above 4km.Its behaviour is weird

February 18, 2015

The Yak-1 goes around 580 km/h TAS at 4000 meters at standard atmosphere (assuming that the speed on the HUD is CAS and not IAS, i'm not sure about that, but the HUD speed differs from the in cockpit gauges). Nothing wrong with that imho, well inside 2% tolerance if you use the 571 km/h or 592 km/h figures that are floating around.

The problems starts above that altitude.

Damn sure it is wrong. Just make a speed comparison with the 190 A3, and you see how wrong it is.

Maybe devs used Yak 1b max speed of 591km/h at ~4km as reference speed.Then addition of 20km/h to get to 611km/h seems legit = increase of speed inbetween +15/-15°C is reffered to in Stepanec book.

And this is legit? Ok so next, when the G6 comes, we just use the K4 performance. Nothing wrong about it?

Try again. My point is that, instead of going on and on and on and on here about how you (and Kwiatek) think things are wrong, summarize your claims about why you think things are wrong and submit them to the team for review. That's the only way things will be changed. This doesn't feel right / the data is flawed / something is off, etc., just doesn't cut it. The team doesn't have time to analyze emotions and how one "feels" about a certain flight model. Like it or not, they deal in facts, and it's been that way since they began coding ROF.

You guys are truly unbelievable. First of all Kwiatek already did exactly that! And look at the answer he got from Zak.

Second of all are you blind? Who does talk about "feelings" here?? Are you making those statements on purpose to annoy people? Alone in this topic here, the numbers and data are in 5 different posts, nothing about feelings. Or are you just to lazy to read them, before making your statements?

Third of all back when i did all that research about the 190, it took me really ages to convince Han what is wrong with the 190 (parts of it), to get the Devs to fix it. I am sure i lost 10 hours in total. That's not my goddamn job. I am a student, and i am working at the same time, 10 hours of my time is worth 150 euros. In the spare freetime i have, i want to have fun, beside doing sports, primarily with flight sims. It's the job from the Devs to get it right, and not mine. And now i shall go through all that again? In this topic there are more then enough posts about what is wrong.

I am pretty sure the Devs have the same data available like us so there is no point in providing them topspeed data of the Yak1 (every available source says the same topspeed), and the other thing is testing it at high alt. They can/must do it themselves, and i think till now enough people made the test, to prove how wrong it is.

Fourth of all..what is this tiny "Tester" signature in your profile? Aren't you supposed to test things like FMs, if they are right or wrong?!

Edited February 18, 2015 by Celestiale

February 18, 2015

Although LukeFF indeed sounds sometimes kind of arrogant speaking or being from another star (which is not offended meant) , he is right in what he posted above.

The forum is not the right place to present ones claims of a wrong modeled fm.

Collect your stuff and get in contact with Han himself.

Forums are always full of emotions and it will be hard to present one claims in a correct frame, as each and everyone has another meaning or is of the opinion to leave his smell aswell.

I appreciate your work for doing "ou" sim better, but the forum is the wrong place to present it.

February 18, 2015

Yea i think we should closed all forums casue it is not point to write anything here

February 18, 2015

Forums are always full of emotions and it will be hard to present one claims in a correct frame, as each and everyone has another meaning or is of the opinion to leave his smell aswell.

I appreciate your work for doing "ou" sim better, but the forum is the wrong place to present it.

Yes, you are definitely right..same thing i lately wrote in one topic in the "general discussion". This section (technical issues) here is at least mostly free of the unreasonable yellers (unfortunately also not completely when i look at the last page). But i think it's good when more people can follow and understand what is wrong, also providing their own sources and tests, like in this case, where pretty much everybody who tested it, came to the same conclusion (that the FM is wrong). It's worth more, then only one person writing a Dev, because there is more "backup-feedback".

February 18, 2015

Damn sure it is wrong. Just make a speed comparison with the 190 A3, and you see how wrong it is.

No, i would rather compare it to real data instead, which i did.

The Fw 190 has nothing to do with this topic. If you think the Fw 190 is too slow, open another topic about that or send data to Han.

February 18, 2015

Sounds very much like a bug has been inadvertently introduced into the game for high altitude Yak / Lagg performance. I don't think it's anything to do with balance as the Yak didn't perform that well before if I remember right.

Hopefully the devs will take a look at this and if there is nothing wrong then provide an explanation as right now the data looks to be pointing to a major enough discrepancy. A blanket nothing will be changed explanation isn't really a good enough response to the tests performed by multiple users. Bugs can be introduced by accident. It happened in DCS recently where the Mustang accidentally lost some speed.

February 18, 2015

No, i would rather compare it to real data instead, which i did.

The Fw 190 has nothing to do with this topic. If you think the Fw 190 is too slow, open another topic about that or send data to Han.

Compared to real life data it's still 40kph to fast at full throttle altitude.

Btw why are you throwing around the Yak1b number? Since when it is ok, that a plane in a Sim has the performance of it's successor?

So when the G6 get's introduced, and has a way better performance then IRL, it's also OK i assume? Because it "matches the performance of the G10 pretty accurately".

Edited February 18, 2015 by Celestiale

February 18, 2015

Matt isn't throwing around any Yak 1b numbers. Somebody else mentioned them. His point is that when it comes to Yak speeds in BOS the only thing to refer to is Yak RL data. Seems reasonable and when users have done this it does seem like there's a significant discrepancy. Really at this point we need the devs to take a look and weigh in. If there's no response after a bit just have to keep poking.

February 18, 2015

Please,focus on problem we all try to sort out.High altitude - above 4km behaviour of M105PF Klimov engine.If Yak-1 can fly 571 or 592km/h at 3650 or 4100m is not important.Values in game are within error margin.Whats going on on high altitudes is point of this thread.So stay focused,folks.

February 19, 2015

Please,focus on problem we all try to sort out.High altitude - above 4km behaviour of M105PF Klimov engine.If Yak-1 can fly 571 or 592km/h at 3650 or 4100m is not important.Values in game are within error margin.Whats going on on high altitudes is point of this thread.So stay focused,folks.

Unfortunately it's not only at high altitude. It's clearly also at 3650..its 40kph to fast at this altitude as well, you just can't ignore that. This has definitely also be taken into account, it's almost as serious as it's high altitude performance

February 19, 2015

Fourth of all..what is this tiny "Tester" signature in your profile? Aren't you supposed to test things like FMs, if they are right or wrong?!

I do, and everyone else on the testing team does that, but at the end of the day it's the programmers that have to decide what data they are going to go with and what will be discarded. Like I've said, they are willing to take another look at the FMs, but they are not going to waste their time unless they are given factual, concrete evidence to review. It's that simple. And, in the end, if they decide to not change something, then that's just the way it is.

Edited February 19, 2015 by LukeFF

February 19, 2015

I think that these topic proved enough that Yak-1/Lagg3 in BOS are way too fast at altitude with 10 % error. Devs know these but from unknown reason dont want to change anything. These unfortunately show their attitude regarding historical accuracy and realism of these sim. So it looks that balancing game is more important here. Whats a pity.

Edited February 19, 2015 by 303_Kwiatek

February 19, 2015

I think that these topic proved enough that Yak-1/Lagg3 in BOS are way too fast at altitude with 10 % error. Devs know these but from unknown reason dont want to change anything. These unfortunately show their attitude regarding historical accuracy and realism of these sim. So it looks that balancing game is more important here. Whats a pity.

Well I dont think that it was proved - at least I dont get it.

Your tests were done with 0% and 25% radiators.

Is this the same setting that was used IRL for the data from RL? Or is this just the same as the setting that were used in German tests of German planes or???

Radiator settings have a big influance on speed, this is clear.

And it is a question of overheating and having resulting speeds.

I havent replicated the tests myself, but flying online I get plently of overheating with relativly opened radiators (50%+) with the Lagg and the Yak. So I dont understand the 0% opened raidiators and 25% opened radiators tests - what good are they if I cant fly in that configuration than?

So it is crucial to know how the tests IRL were done and test at that setting and than compare.

Same for german planes - we all know that we can fly the 109 non stop with completly closed radiators and get a big speed boost.

How are the speeds for the 109 in that case - 0% radiators and 25% radiators - compared to RL speeds.

Maybe its all a question of overheating and that the planes dont overheat enough? Or its just cold and the weak cooling on the Yak and Lagg are not exposed so much and as a result the planes apparently have much higher performance.

Its a double effect - colder air for more power and less drag because less radiators needed?

Its same in the 109 with constantly closed radiators so double the effect?

Maybe its and inline engine thing and the radials dont benifit that much from it due to having less external radiators and cant reduce the drag that much with closing of the radiators due to the cool air.

The important thing is to have the IRL data for speeds with the coresponding radiator / fuel... settings and athmosperic conditions.

Than something can be said about the performance of the planes and how it matches RL.

And I didnt see that here - no temperatures, no pressures, no fuel loads (talking IRL tests), not even exactly the data for the series of Yak / Lagg that we do have ingame.

That is the minimal ammount of data that someone would need to adjust the performance.

February 19, 2015

Compared to real life data it's still 40kph to fast at full throttle altitude.

Btw why are you throwing around the Yak1b number? [snip]

The 571 km/h at 3650 m that "i am" throwing around (see page 1) is not a Yak-1b number.

I have not tested the performance at 3650 meters (only 4000 and 6000 meters), so if you consider that necessary, i can do that today. Again, that's not what this topic is about and i doubt that it will reach 611 km/h ("40 km/h too fast"), but shouldn't take long anyway.

Or did you actually test that at standard atmosphere conditions?

February 19, 2015

Well I dont think that it was proved - at least I dont get it.

Your tests were done with 0% and 25% radiators.

Is this the same setting that was used IRL for the data from RL? Or is this just the same as the setting that were used in German tests of German planes or???

Radiator settings have a big influance on speed, this is clear.

And it is a question of overheating and having resulting speeds.

I havent replicated the tests myself, but flying online I get plently of overheating with relativly opened radiators (50%+) with the Lagg and the Yak. So I dont understand the 0% opened raidiators and 25% opened radiators tests - what good are they if I cant fly in that configuration than?

So it is crucial to know how the tests IRL were done and test at that setting and than compare.

Same for german planes - we all know that we can fly the 109 non stop with completly closed radiators and get a big speed boost.

How are the speeds for the 109 in that case - 0% radiators and 25% radiators - compared to RL speeds.

Maybe its all a question of overheating and that the planes dont overheat enough? Or its just cold and the weak cooling on the Yak and Lagg are not exposed so much and as a result the planes apparently have much higher performance.

Its a double effect - colder air for more power and less drag because less radiators needed?

Its same in the 109 with constantly closed radiators so double the effect?

Maybe its and inline engine thing and the radials dont benifit that much from it due to having less external radiators and cant reduce the drag that much with closing of the radiators due to the cool air.

The important thing is to have the IRL data for speeds with the coresponding radiator / fuel... settings and athmosperic conditions.

Than something can be said about the performance of the planes and how it matches RL.

And I didnt see that here - no temperatures, no pressures, no fuel loads (talking IRL tests), not even exactly the data for the series of Yak / Lagg that we do have ingame.

That is the minimal ammount of data that someone would need to adjust the performance.

Yak-1 test were done at 25% radiator and 0 %. With 25 % radiator in BOS Yak-1 reached at 6 km 600 kph and with 0% reached 611 kph TAS. There were no overheat problems with level flight at such speed in test.

German data show they made speed test with 1/4 ( 25 %) radiator opens. So i made all test with 25 % radiator opens for all planes for comparsion.

There is no way possible that Yak-1 with 105 PF engine could reached 600-610 kph TAS at 6 km. RL data claimed about 540-545 kph TAS at these alt.

G-2 and A-3 at 6 km got very accurare results comparing to RL - below 2 % error. F-4 is little got more error.

What is hard to understand here?

Yak -1 and LAgg-3 with M-105 PF engine ( very low altitutde engine version) IRL reached their maximum speed at. 3.6-3.7 km in 1942. They can't be faster at 6 km as it is in BOS actually. Morover they shouldn't be faster then La5 which got very accurate speed results ( with 25 % open radiator also) comparing to RL. La5 was faster at alts then Lagg3/Yak-1 casue it has simpy more engine power at these alts.

What is so hard to understand here?

Thats it how it work in these game - Yak-1 and Lagg3 are overspeed at alts with huge error.

So solution is other planes should be also more faster ( 109, Fw 190 and La5 ) which would be little absurd casue they have accurate results or Yak-1/Lagg3 should be slowier casue they got huge error here.

Edited February 19, 2015 by 303_Kwiatek

February 19, 2015

The 571 km/h at 3650 m that "i am" throwing around (see page 1) is not a Yak-1b number.

---->

well inside 2% tolerance if you use the 571 km/h or 592 km/h figures that are floating around.

here you were clearly talking about 592kmh.

I have not tested the performance at 3650 meters (only 4000 and 6000 meters), so if you consider that necessary, i can do that today. Again, that's not what this topic is about and i doubt that it will reach 611 km/h ("40 km/h too fast"), but shouldn't take long anyway. Or did you actually test that at standard atmosphere conditions?

I tested in BoS conditions, and Kwiatek calculated the IAS into TAS with a TAS calculator. I think that comes closer then your assumption that "the HUD speed might be CAS". We definitely know that instrument speed is IAS, so taking this value is definitely safer.

Assuming that your CAS calculation would be right - well, then the Devs would have really f***ed up this game, because every fighter but the Yak would be to slow.

Just my personal opinion to all those performance issues now - i don't care if this fighter, or that fighter meets certain values spot on. I just don't know how much this cold air boost changes, i don't know how much this density variation distorts your IAS to TAS calculation. But i do know the performance/speed difference between every fighter at most altitudes IRL, and the difference between them in game should be exactly the same. I don't care when this plane flies 10kph to slow, if every other plane also flies 10 to slow.

I don't have all availabe data here (i think not even the Devs have) to exactly tell how fast the planes should go in Stalingrad Winter 42 conditions either IAS or TAS. There are to many variables. But i have never heard of a natural variable which gives different planes different performance changes.

All this talking by you, and other people "i don't care about the difference between the planes, we are only talking about plane XY here, and this is right because ......." because there will always be an excuse, why a certain plane "performs right". Then a discussion about the next plane is started, and suddenly the reasons which made the last plane "performing right" are no more valuable, and another excuse is found why this particular plane "performs right" again.

This way we got a historic completely wrong (almost ludicrous if you take the time to compare the planes, and then look at the real life data) balance between the planes, where the planes have strenghtes and weaknesses they never had IRL.

Edited February 19, 2015 by Celestiale

February 19, 2015

Of course its not matching for me.

109 radiators were at 25%. That is ok and that is a comparable test.

You now assume that the Russian planes also were at 25% for the test IRL. Are you sure that this is the case - or writen differently, what settings were they using really for those tests? Maybe they used 75% and that is why you get the difference and acctually the cooling is too efficient on the Russian planes - or the tests were done in summer and they needed to open the radiators more...

Fact is that they overheat more than the 109. So you dont get overheating of the Yak at 25% (dont know how, but ok - I guess you just use quick mission generator and spawn in air - what should be done is to acctually take off, get to the altitude and do the test).

But 109 gets no overheating with 0% radiators. So what now - the relative performance difference for me is at which setting the plane can consistently fly and what speed is achived at that point.

There is no way possible that Yak-1 with 105 PF engine could reached 600-610 kph TAS at 6 km. RL data claimed about 540-545 kph TAS at these alt

RL data claimed 540 - 545 TAS -> what were the conditions there. Which radiator settings, what air temprature, what atmosperic pressure????

I am not saying at all that BoS is right - but to do some changes the data must be described fully. And your data is not - far from it.

What you do is to make the same test for the German and Russian plane (25% radiators) and than cry faul. But this is not correct - for the German tests its correct, but for the Russian one it is not as you are not using the same radiator setting as was used in the test IRL.

So you are proving something. I could just as well now go fly the 109, used 100% radiators and complain that it is far too slow. Or 0% radiators and complain that it is much to fast. Or take the Yak, use 100% radiators and complian that it is too slow.

It dosent work that way - its not comparable.

To compare you must use the same settings in the game as were used IRL. Than you get something.

And if the planes are cooled too easily the issue is with the cooling - or with the cold conditions...

That is why it is necesary to provide the complete data to get the right results.

And about real advantages - from where do these claims come from? Is it really the pilots or just a bunch of data interpreted by some historians? Or just assumed performance advantages that we sim pilots know of due to us reading the data and knowing how we fly some planes (or would like to fly some planes in some cases).

The fact is that test give us data. This data can only be compared with other data if that test is done at the same conditions.

If not we are just assuming things.

And to be clear - I am sure that it is very tricky to get hte drag from the radiators right and the perfornace of the radiators. And not having data of planes with 0%, 50% and 100% opened radiators makes it very difficult to model the performance correctly and is a big possibility of having some areas of performance completly off (lets say 0% or 100% radiators). I suspect that BoS has a problem here and that this is why our assumptions of relative performance are not completly visable in the sim.

February 19, 2015

The fact is that test give us data. This data can only be compared with other data if that test is done at the same conditions.

If not we are just assuming things.

Not wanting to get squashed in the battle here, but I object to this on theoretical grounds.

In reality, no experiment can be repeated "at the same conditions"; there is always something that cannot be controlled for. Repeated tests are at best approximations of one another.

So to compare tests we need to take a probabilistic approach. If we get an odd looking results comparing two tests we can justifiably look at different explanations: in this case the "one engine is over-modeled" vs the "significant variable in the two tests was not specified" explanations, and ask which explanation is more probable.

Which is more probable in this case I leave to others to decide, but the idea that it is impossible to reach conclusions without some idealized standard test conditions is absurd: most of human knowledge would be impossible on this basis.

February 19, 2015

I tested in BoS conditions, and Kwiatek calculated the IAS into TAS with a TAS calculator. I think that comes closer then your assumption that "the HUD speed might be CAS". We definitely know that instrument speed is IAS, so taking this value is definitely safer.

Assuming that your CAS calculation would be right - well, then the Devs would have really f***ed up this game, because every fighter but the Yak would be to slow.

Kwiatek calculated CAS into TAS, not IAS into TAS. And not with standard atmosphere conditions.

I don't have all availabe data here (i think not even the Devs have) to exactly tell how fast the planes should go in Stalingrad Winter 42 conditions either IAS or TAS.

That's why it makes no sense to test the performance of the planes in BoS at anything but standard atmosphere conditions, if you want to compare the performance to real data (which is not what Kwiatek was aiming for with this topic).

February 19, 2015

Kwiatek calculated CAS into TAS, not IAS into TAS. And not with standard atmosphere conditions.

That's why it makes no sense to test the performance of the planes in BoS at anything but standard atmosphere conditions, if you want to compare the performance to real data (which is not what Kwiatek was aiming for with this topic)

CAS or IAS is not such metter here - i used the same reference from achived speeds by all these planes to calcutade TAS in ISA condtions.

It show relative performacne of these planes. It is enough for our purposese.

Some planes like 109 G-2, Fw 190 A and La5 which these test and calutation ( IAS/CAS ----> TAS) showed are very accurate to RL data and charts for these planes in ISA conditions ( within 2 % error).

Some plane like Lagg-3 and Yak-1 are way too fast with 10 % error. It clearly broke relative performacne of all these planes.

I thought these is quite simple to understand.

I think some dont know what what exacly mean low altitude supercharger settings ( like with M-105 PF engine which got peak at 2700 m) and its physical and logical influence of engine power drop at high alts.

Edited February 19, 2015 by 303_Kwiatek

February 19, 2015

Yes, of course it's enough for comparing the relative performance of the planes and it's clear what you're trying to say.

It's not enough for comparing the speed of a plane with flights tests which were done under different conditions, which someone else is trying to say.

February 19, 2015

Still suprisly some planes are really very accurate ( below even 2 %) using these calculation from achived maximum speed in BOS test and comparing to RL data and charts from ISA condtions. I mean here 109 G-2, FW 190 A-3 and LA5. There are only with max 10 kph error here ( less or more).

Edited February 19, 2015 by 303_Kwiatek

February 19, 2015

So to compare tests we need to take a probabilistic approach. If we get an odd looking results comparing two tests we can justifiably look at different explanations: in this case the "one engine is over-modeled" vs the "significant variable in the two tests was not specified" explanations, and ask which explanation is more probable.

Not really.

There is tons of variables missing in the data. And the tests ingame Were conducted in such a way that comparisons are done of 25% radiator for 109 v 25% radiator for Yak. Yak is close ot overheating (or overheats in my case) and 109 is far from it. Ingame you can fly the 109 with 0 radiators non stop and Yak at more than 25% if you want to not overheat at one point.

Tests IRL were done at some conditions under some standard.

That is the only thing that needs to be provided here - how were the tests done, what were the results and the final conclusion (performance specs). And this for all the planes. Its not a probability question at all - its a comparison between test conditions IRL and sim question. Just adjust the conditions and make comperative tests.

For that we need RL test data and the possibility to replicate this in the sim (pressures, temperatures, plane settings...)

The relative difference of the tests than comes out of physics. So to check if this holds up in the sim (drag, cooling....) these need to be crosschecked again with test data with different conditions (0% radiators open, 50% radiators open...)

It would be great to get the info from the devs on this I absolutly agree (this was one of my suggestions to the devs ages ago at the start of hte developement to provide all the data and how they are interpreting it to avoid these sort of disscusions). But if we want to say that the sim is giving out the wrong results we must say what is wrong and provide the data where it shows that it is wrong (not partial cherry picked data, but full tests with all the necesary data to model this in the sim!)

Get that data and I am sure that the devs will do something.

And Kwiatek - your claims mean very little without the data about the RL tests - the conditions under which the performance was measured. Get those, compare accordingly - than there is no question.

February 19, 2015

Well if Yak-1 with M-105 PF engine in 1942 got maximum speed 600 kph or 610 TAS at 6 km all known suorces surly would show 600/610 kph in 6 km instead 571 kph at 3.65 km.

I will reapeat again :

Planes like G-2, A-3 and La5 are really very accurate ( below even 2 %) using these calculation from achived maximum speed in BOS test and comparing to RL data and charts from ISA condtions. There are only with max 10 kph error here ( less or more).

For some reason Yak-1/Lagg-3 at 6 km got 50-55 km/h error here which give 10 % error.

I dont know exacly reason for these ( no overheat, too much engine power or rather both of these two combided) but it show achived performacne of these planes in game which is not accurate for relative performacne of these planes IRL.

Rest is just empy talk if someone dont understand these.

Edited February 19, 2015 by 303_Kwiatek

February 19, 2015

... I could just as well now go fly the 109, used 100% radiators and complain that it is far too slow ...

This is just demagogy. Do you understand that max speed test is conducted to find maximum speed? Maximum is an extreme obtainable/available/possible ... If you do not provide optimal conditions you are not testing maximum speed. You are testing "maximum speed under a non optimal setup / or specified conditions". Maximum speed test is conducted with optimal settings for given ambient conditions. You do not criple your craft for moaning purposes.

There are many variables in the equation and unless we are given standard atmosfere we won't be able to test the planes under standard conditions. There is possibility that different conditions may have somewhat different influence on individual types of planes performance. But that doesn't mean one has to shift the debate to demagogy. Kwiatek has taken an above standard effort to prove his claims and even if devs will come with a plausible explanation of current state of the game he deserves respect.

In this regard i'm looking forward to the announced summer and autum maps. They will provide a playground for more tests.

February 19, 2015

@PeterZvan: All empirical knowledge relates to probability, there can be no complete specification of the conditions in principle, only continued approximations. As you say, "There is tons of variables missing in the data": and there always will be.

We cannot know more about the RL tests than is available. We can only know so much about what is going on in BoS since we cannot alter pressure and temperature in the game (I think). So you are asking for a standard of testing that is simply unattainable at present. Hence we have to say, on the information available, what we think is going on.

Celestiale and Kwiatek have identified something that looks odd, to say the least.

February 19, 2015

This is just demagogy. Do you understand that max speed test is conducted to find maximum speed? Maximum is an extreme obtainable/available/possible ... If you do not provide optimal conditions you are not testing maximum speed. You are testing "maximum speed under a non optimal setup / or specified conditions". Maximum speed test is conducted with optimal settings for given ambient conditions. You do not criple your craft for moaning purposes.

There are many variables in the equation and unless we are given standard atmosfere we won't be able to test the planes under standard conditions. There is possibility that different conditions may have somewhat different influence on individual types of planes performance. But that doesn't mean one has to shift the debate to demagogy. Kwiatek has taken an above standard effort to prove his claims and even if devs will come with a plausible explanation of current state of the game he deserves respect.

In this regard i'm looking forward to the announced summer and autum maps. They will provide a playground for more tests.

You dont understand what I am getting at.

My issue with the test from Kwiatek is that he takes 25% of radiator for the tests. Which is fine for 109 as this was stated in the real 109 tests to have been the case. All fine and well. The results in game are very close as the results IRL - excelent.

But for the Yak tests its not fine. In game performed with 0 radiators and 25% radiators. Results are as they are - much too fast according to the RL data.

RL data we dont know what was the settings used to get these results - maybe it is writen somewhere, but I havent seen it mentioned once.

So what is maximum speed - maximum attainable level flight / after a dive maximum sustainable speed / with completly closed radiators / without bullets ....????

First lets get that clear and compare the planes than.

For me as a relative performance figure in the sim it is the speed at level flight without previous dives with optimum settings which can provide a sustained prolonged flight.

So the 109 at 0 radiators, the Yak at 25% radiators (I am still unsure here as I always need to use more in MP)...

Also the 109 can have the prop pitch adjusted manualy to get it faster if we go that far (substantialy faster acctually). Same for the 190.

Those need to be relativly comparable to each other and than all is fine I guess.

However in game the 109 is than overperforming as I can use 0% radiators non stop and be much faster than RL data. This nobody wants to touch at all and nobody complains about - funny that fact.

And now look at the relative performance of the planes - all with the max attainable speeds ingame with all sorts of ways of getting them (fly the 109/ 190 / Lagg / Yak / La in a coordinated fashion by yourself and with manual prop pitch / manual radiators as closed as possible after a take off)

Something does look odd - I am not saying that it dosent - not even once did I write that.

How much is this odd - to what to fix that speed is what is at question here.

How can the devs change something if they dont know how far off they are? Provide that ammount of discrepency with enough data so that the engineers from the devs can do something with that data.

My oppinion is that the radiators are too efficient on the inline planes and that the drag from the radiators is not right over the complete radiator range.

That is why we dont get the overheating and huge performance of the inline planes. And relativly the Yak and Lagg are apparently faster as they should be.

Lets get the base data of what they should do at what radiator setting and temperature and things can get fixed easily - and I dont think that devs will dispute anything than.

And someone should do a test of the 109 with 0 radiators and manual pitch control (1,3ata and 2800 / 2850 revs - they can sustain that quite long) + usage of rudder to have no side slip.

Lets see the relative speed difference than.

February 19, 2015

This is just demagogy. Do you understand that max speed test is conducted to find maximum speed? Maximum is an extreme obtainable/available/possible ... If you do not provide optimal conditions you are not testing maximum speed. You are testing "maximum speed under a non optimal setup / or specified conditions". Maximum speed test is conducted with optimal settings for given ambient conditions. You do not criple your craft for moaning purposes.

It's less demagogy, more the case of requirements.

Each plane is designed to meet specific, given by the engineers, numbers. They are not testing maximum speed but rather testing if airframe they designed, powered by specific engine is meeting the calculations done before prototype was designed.

And no, I'm not saying Kwiatek is wrong. I'm not saying he is correct either. But what is PeterZvan saying is true, to compare the tests done in game to the tests done in real life you have to recreate the exact settings and conditions under which the airplane was tested.

February 19, 2015

@PeterZvan: All empirical knowledge relates to probability, there can be no complete specification of the conditions in principle, only continued approximations. As you say, "There is tons of variables missing in the data": and there always will be.

We cannot know more about the RL tests than is available. We can only know so much about what is going on in BoS since we cannot alter pressure and temperature in the game (I think). So you are asking for a standard of testing that is simply unattainable at present. Hence we have to say, on the information available, what we think is going on.

Celestiale and Kwiatek have identified something that looks odd, to say the least.

We agree with each other here - what I want to say is that if we want to change the devs we need to go the extra step - find the info that is missing. Else their interpretation is at least as good as ours and who is to say who is right.

We need the data - it must be somewhere - official tests have the specifications of the tests.

February 19, 2015

I think you guys still dont understand what is relative performacne between these planes. If you dont understand these there is no point to talk futher.

I dont care if all planes will be faster by 50 kph but if all will be faster at similar way.

So now LA5, G-2 and A-3 should be faster at 50 kph at 6 km to keep relative performacne with Yak-1/Lagg3. It is simple.

What is worry me more it is devs attitude. It show that they dont care as much in historical accuracy. I think that we could see more such things in the future. There rise a lot untrust in their products.

Im sure think a lot before i buy another sequel. Maby there is better to invest money in other sim where devs care about realism and historical accuracy.

Edited February 19, 2015 by 303_Kwiatek

February 19, 2015

I will quote from comrade Stepanec book:

To achieve max speed and climbrate

1. For Yak 1 water radiator flap is opened 150mm (for Yak-7/9 200mm) = make radiator adjustment wheel to position "max open" and then go 3-4 full turns back

2. For all Yaks oil radiator flap to be opened at 90mm = make radiator adjustment wheel to position "max open" and then go back 1 full turn back

And definition of max speed itself:

The maximum speed is the one that airplane can reach in level flight for a long time without any abnormality and damage to the craft and its components, with the most complete and correct use of the factors affecting the speed.

February 19, 2015

Exactly Brano. Maximum speed is not a theoretical value only to be confirmed by tests. It's by definition maximum sustainable speed given the AC is operated correctly. And test pilots have always been competent to determine this maximum. On top of that Kwiatek clearly states that the most suspicious is the fact some AC achieve max speed at different than expected altitudes. Not only that they are too fast but mainly that they overspeed at altitudes way above their rated max speed altitude. Plus Bf 109F4 is also mentioned so it's not some hot air blue talk.

I can't understand some people in my eyes definitelly knowledgeable in this field talk about radiators and cool air and do not stop right at the fact that the low alt engine gives the Yak max speed at 6000m. This is a no go. You may argue that some AC receive larger boost because their construction favores this cold weather and some don't get as much because radial engines have high drag even if shutters are closed. But there is no feasible explanation for a totally different performance envelope. Either there must be sources proving the Yak 1 equiped with the M-105 PF engine performed better at 6000m than at 4000m or it's an error. It's not only a matter of relative performance of different types of AC but also relative performance of this single type in regards of altitude.

A final note: when i studied dynamics and simulations the proffesor always told us "Never fall in love with your (mathematical) model" and I add "The real system is always right". Simulation is always wrong. The only question is by how much.

February 19, 2015

Yes,performance of klimov above 4km is topic here and I agree that there is problem of overspeeding at those given alts.My humble oppinion - smtg is wrong with vysotnyi korrektor.Engine acts at 6km as it was still at 3.5-4km.

February 19, 2015

A final note: when i studied dynamics and simulations the proffesor always told us "Never fall in love with your (mathematical) model" and I add "The real system is always right". Simulation is always wrong. The only question is by how much.

I really like these sentence

February 19, 2015

Again according Stepanec:

max speed of Yak-1 with 105PF engine before and after s.99 (from this series there was first plane tested with aerodynamical improvements suggested by CAGI and LII)

Before After

improvement

Маx speed, км/h

ground level ..................... 516 523

1st critical altitude ................ 565 (1950 м) 568 (1850 м)

2nd critical altitude ................ 589 (3950 м) 595 (3850 м)

At 5000 м ............ .....574 579

Yak-1 with older M105PA engine

Маx speed, км/h

ground level ..................... 471-473

1st critical altitude ................ N/A

2nd critical altitude ................ 560-573 (4860м)

February 20, 2015

These data for Yak-1 before 99 ( series ) looks still optimistic. We have in game Yak-1 from 42 ( 69) serie ( who knows what difference were between 69 and 99 serie?). Also wonder what was take off weight of these Yak. As i know Russian often take some equimpment and armamanet from standart Yaks to drop some take off weight. These data before 99 series looks for me as for such reduced take off weight Yak-1 ( maximum speeds was reached at little higher alts )

Most known data are not such optimistic. 500-510 kph at sea level and 571 kph at 3.65 km. Thats for sure for standart Yak-1 from 1942.

February 20, 2015

It was standard serial plane from production.Series 99 was october/42 production,tested plane was nr.16 of that 99.series.Switching from PA to PF increased speed by 20-24km/h finaly meeting I26-2 prototype performance.Further aerodynamical improvements increased it ,if only marginaly (+3-6km/h for later series from 111. till the last 192.).Personaly,I think that Stepanec is quite an authority for yaks.So if devs used his data,then someone should perform new test at 5km if yak can get to 574km/h TAS.I cant do that,out of my gaming PC for at least another week.

February 20, 2015

Kwiatek can you give me the link of your Tas calculator? I will compile a proper report the next days about high altitude imbalance between the planes and sent it to Han.

Don't see any point anymore to discuss in the forum, because anytime you find some flaws there are just to many people trying to highjack your concerns, with any methods available..no matter how obvious the flaws are. It was exactly the same back then with the 190

February 20, 2015

I will compile a proper report the next days about high altitude imbalance between the planes and sent it to Han.

Better send it to Zak. My report has not been read by him for more than 3 weeks now.

I like he ammount of (productive) contribution in here and wish I could help, but my times of being part of the FM buisness are long over. I feel confirmed by your ad Kwiatek's test hwoever in my initial impressions about plane performances and hope you'll finally be able to convince the devs.

Wrong Russian fighters performance at high alts again

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