440km/h ias at 6K, Yak 1b?

[L3Pl4K]

Is it possible that the yak 1 b overperforms at altitude? I make a testflight on Stalingrad autumn at 6k, wind 0m/s. Fuel 100%, mixture 80%, oil radiator 25%, water radiator 20% to set oil and water to 100°C. Reaching ~440 kph ias. Tacview shows ~ 610km/h tas. Is the full throttle alttiude of the Klimov 105pf  not ~4000m? Should the performance not drop?

[303_Kwiatek]

Yes it overperform the same like Yak-1 and 109 F4. Yak1b should achive ab. 600 kph at 4 km then speed should significantly drop. It was proved many times here. Its rather known fact.

Btw if tacview show TAS now it is even more proveable without needed futher conversion IAS to TAS.

 

Peak power at 2nd supercharger for Klimov M105 Pf engine is 2700 m and maximum speed achiveable for Yak1s is range 3800-4000 m. Then power and the same speed should significanlty drop. At 6 km even old Db601a got more power then Klimov engine

Edited May 25, 2017 by 303_Kwiatek

[L3Pl4K]

Has someone sources for the yak alt performance?

[303_Kwiatek]

They were in similar topics

[L3Pl4K]

Ok i found this offical statement:

https://forum.il2sturmovik.com/topic/26139-new-yak/?p=410889

This little 3,8% relegated the Gustav. With the real life advantage of ~50 kph, it is possible to gain ~830m separation in 1 minute. With the ingame~25kph a gain of ~420m is possible. This quite noticeable.
 

[-=PHX=-SuperEtendard]

You are having the radiators a bit too closed to compare with the IRL speed testing, which according to one of the devs when the Yak-1B was released was around 50% for water and 35% for oil IIRC,although I guess the speed difference won't be that big... (just a little remark to have the test 100% comparable )

Edited May 25, 2017 by -=PHX=-SuperEtendard

[L3Pl4K]

 

 

You are having the radiators a bit too closed to compare with the IRL speed testing, which according to one of the devs when the Yak-1B was released was around 50% for water and 35% for oil IIRC,although I guess the speed difference won't be that big... (just a little remark to have the test 100% comparable )

Sure but noone will fly with this radiator settings

[Finkeren]

Sure but noone will fly with this radiator settings

No, but the fact that we run our engines insanely hot, much hotter than you'd do IRL, doesn't mean that top speeds should be based on anything other than the historically used radiator settings.

[-=PHX=-SuperEtendard]

Sure but noone will fly with this radiator settings

 

Sorry, I didn't mean to sound snarky (that's why I put the face, but I guess it made the opposite effect). Thing is that in order to properly test if the plane is correctly modelled or not speed wise, you have to use the same testing standard as IRL, because if not you can't really extrapolate. What setting people uses in game has little importance really.

Edited May 26, 2017 by -=PHX=-SuperEtendard

[L3Pl4K]

 

 

Sorry, I didn't mean to sound snarky (that's why I put the face, but I guess it made the opposite effect). Thing is that in order to properly test if the plane is correctly modelled or not speed wise, you have to use the same testing standard as IRL, because if not you can't really extrapolate. What setting people uses in game has little importance really.

The fact is, if i use the "orginal" Radiator settings, the temps are very conservative. Oil ~70°C Water 62°C. Topspeed is 426kmh ias. The speed looks ok, but the temps looks to "low". The operaton limits for oil and water are 100°. The shorttime limits are higher.

[LLv34_adexu]

The fact is, if i use the "orginal" Radiator settings, the temps are very conservative. Oil ~70°C Water 62°C. Topspeed is 426kmh ias. The speed looks ok, but the temps looks to "low". The operaton limits for oil and water are 100°. The shorttime limits are higher.

 

Probably over performing comes from that? You can fly with more closed radiators than IRL. But, what it would change if we write about it here. In my opinion Yak climbs too well too. Also you can fap the stick in Yak-1b, and enemy wont hit you as you can't fap the stick that way in any other plane.

[303_Kwiatek]

Real Yak-1 max speed 590 kph at 3800 m and 15 m/s climb rate. BOS Yak-1 much better then these

[StG2_Manfred]

Probably over performing comes from that? You can fly with more closed radiators than IRL. But, what it would change if we write about it here. In my opinion Yak climbs too well too. Also you can fap the stick in Yak-1b, and enemy wont hit you as you can't fap the stick that way in any other plane.

Exactly! Today we made a couple of flights on Berloga server. The Yak 1b has no overheating problem, still benefits from flaps, fly like on rails, overperforms in climb rate - and left us speechless We'll see what happens when the FM update comes, whether something will change or not. But then the next Russian planes are just around the corner we think. Better stand on the sidelines and look in what direction this all will go...

[LLv34_adexu]

Exactly! Today we made a couple of flights on Berloga server. The Yak 1b has no overheating problem, still benefits from flaps, fly like on rails, overperforms in climb rate - and left us speechless We'll see what happens when the FM update comes, whether something will change or not. But then the next Russian planes are just around the corner we think. Better stand on the sidelines and look in what direction this all will go...

 

You are really a bit too optimistic about the FM update. It's a premium plane (pay to win). The view to the back, maneuvering, speed, the weapons, just makes me wonder, what kind of plane Yak-3 was (which my grandfather praised, as he was serving at a/f during the war) if Yak-1b is performing like this... 

 

That is your opinion.. and an erroneous one at that. Please keep it to yourself. 

Edited June 11, 2017 by Bearcat

[L3Pl4K]

 

 

It's a premium plane (pay to win).

This allegation is  hard. It is more believable,  the devs had/have not enough time/money for fine tuning.

[BlitzPig_EL]

If the Yak 1b is pay to win, then the P 40 is pay to lose.

 

Get over yourselves.

 

BTW where is the outrage over the over performing F4? 

 

 

There is a global problem with the game engine that affects aspects of all the aircraft in the sim, and it has been here since day one.  

The devs admissions about the airflow modeling and it's effect on control surfaces is the tip of the iceberg of this problem.

 

 

Making a flight sim is a lot harder than most realize, and the more realistic they try to make it, the higher the difficulty becomes, and the more unforeseen issues that will happen.

Edited June 5, 2017 by BlitzPig_EL

[Barnacles]

I think the problem in general is the radiator performance, in all planes. If you use historical radiator settings the planes all seem to achieve their historical speeds. The 109s' auto radiator barely ever opens, it seems, even in a vertical climb at combat power. It is only possible to overheat some planes if you fully close the radiators. (p40, 109e7 for example)

[LLv34_adexu]

If the Yak 1b is pay to win, then the P 40 is pay to lose.

 

Get over yourselves.

 

BTW where is the outrage over the over performing F4? 

 

 

There is a global problem with the game engine that affects aspects of all the aircraft in the sim, and it has been here since day one.  

The devs admissions about the airflow modeling and it's effect on control surfaces is the tip of the iceberg of this problem.

 

 

Making a flight sim is a lot harder than most realize, and the more realistic they try to make it, the higher the difficulty becomes, and the more unforeseen issues that will happen.

Could you link thread where F4 is over performing?

 

I think the problem in general is the radiator performance, in all planes. If you use historical radiator settings the planes all seem to achieve their historical speeds. The 109s' auto radiator barely ever opens, it seems, even in a vertical climb at combat power. It is only possible to overheat some planes if you fully close the radiators. (p40, 109e7 for example)

Don't have p40 as I hear it sucks, don't fly E7 as much as I should. But I think that radiator performance is not only problem Hope they would fix things faster.

[JtD]

Actually, comparing the Yak-1 cooling real life to game, they don't seem to be overly optimistic. Tested with the S69, with fully open radiator oil (red) seems to be where it belongs, water (blue) slightly higher. With radiators at 50%, both water and oil are considerably hotter than they were in the reference. While 50% is flush for the water radiator, 50% is more open than flush for oil. In what can be considered flush for the oil, maybe 20%, oil temps go rapidly up to 115°.

 

The most striking difference between game and real life is the speed at which the temperature changes. Obviously, heating up or cooling down several hundred kg of metal, oil and water does take or free a lot of energy, and the game does not take this into account properly.

[Holtzauge]

With the reservation that this is old data (pre 2.007 patch) and I have not had time to update it, I still think it could be interesting because when it comes to climb performance it actually looks like the Me-109F4 and G2 not the Yak-1 s69 are the worst offenders.

 

I made a few observations in the spreadsheet and what sticks out most is the G2 climb, the German fighters poor turn performance at higher altitudes and that the Fw-109A3 was consistently slightly undermodeled while the others were a bit on the plus side.

 

Of course the Fw-190A3 has been adjusted since then but AFAIK the Me-109G2 FM has not been tuned? If so this would indicate that it is the G2, not Yak that is much too “stronk” in climb.

 

[Brano]

Hi JtD,

 

Good post there.I have few remarks to your graph,if I may.

1. It says M-105P engine,which is of early yaks (PA version has been produced till may 42)

2. If it is M-105P,then MP of 1045 mmHg is out of limits (in forsazh it was max 950mmHg for M-105P)

3. RPM of 2550 is less then nominal of 2700 for PF version. But on the other hand it was recomended setting at 1st supercharger gear not to exceed max allowed temperatures.

 

Graph values resamble the tests soviet did in april 1942,with standard M-105PA engines forced to 1050 mmHg,which later become standard for PF version. During test they didnt use full 2700rpm,as temperature was rising up rather quickly (in 2 minutes).They set it for 2400-2550.

 What rpm setting did you use in your test? 

[JtD]

I don't really think the difference between P and PF matters that much, given how easily they could be and were converted. I'd also suspect that the cooling wasn't changed for worse in the S69.

 

I've been flying in standard atmosphere at 1000m, which is pretty much what the Soviets did in that test, and I was using 2550rpm (85%) and 1050mm boost (100%).

 

Where did you find the additional info about that test? Any more hard figures in there?

[Brano]

It's from A.T.Stepanec book. No graph there,only info about tests done in April 1942 on standard M-105PA engines forced to 1050mmHg.

Of course on s69 the cooling was not changed for worse. On contrary,to mitigate the increase of engine emitted heat with PF version,new oil radiator has been installed with larger cooling area. It was more of an inherited problem of oil leakage with M-105 family thru gas release valve of engine's crankcase. Gradually covering oil cooler inlets, further reducing it's already underrated heat dissipation. OP-252 type of M-105P oil radiator had 800-850cal/min. Required value was 1000.

Edited June 6, 2017 by Brano

[Venturi]

The most striking difference between game and real life is the speed at which the temperature changes. Obviously, heating up or cooling down several hundred kg of metal, oil and water does take or free a lot of energy, and the game does not take this into account properly.

 

Easy enough to calculate.

 

mass of material X specific heat = Thermal J absorbed for 1 deg C delta

 

Run each series of calcs, one for oil, one for aluminum block, and most importantly, one for the coolant. This should give you a total J for 1 deg change in SYSTEM heat (easy enough to get coolant temp, etc, from that since it is by far the most important value).

 

Of course, rapid changes in J would impact aluminum and oil temperature more rapidly than it would coolant...

[9./JG27MAD-MM]

I mean the Data that is very well documented like Top Speed and Constant Climp Performance and Turn Rate ist not big evidence here.

More things like Parasite Drag in a Turn Flying and Climbing with Flaps deployed AOA  and accelerate are more or less compare later togheter to a Energy Managment how on Earth you can claim this is correct or not?

[LLv34_adexu]

With the reservation that this is old data (pre 2.007 patch) and I have not had time to update it, I still think it could be interesting because when it comes to climb performance it actually looks like the Me-109F4 and G2 not the Yak-1 s69 are the worst offenders.

 

I made a few observations in the spreadsheet and what sticks out most is the G2 climb, the German fighters poor turn performance at higher altitudes and that the Fw-109A3 was consistently slightly undermodeled while the others were a bit on the plus side.

 

Of course the Fw-190A3 has been adjusted since then but AFAIK the Me-109G2 FM has not been tuned? If so this would indicate that it is the G2, not Yak that is much too “stronk” in climb.

 

Are you top level aerodynamical engineer? Like project manager or leading engineer? If you are not, good. If you are, could you type down the planes you were involved with?

[Holtzauge]

Are you top level aerodynamical engineer? Like project manager or leading engineer? If you are not, good. If you are, could you type down the planes you were involved with?

 

Well depends on what you mean with top level...

 

On a more serious note: I have an MSc in aeronautical engineering and the C++ simulations results I sometimes post are from an extension of a program I coded for my master’s thesis which originally was to determine the effects of external stores on modern jets. And since you asked, I have worked on the AJ37, JA37 Viggen and JAS39 Gripen, both in engineering and in project management. But I’m not claiming to be right because I have an MSc, there are plenty others here in the forum who are quite knowledgeable so as in all other things on the internet you have to read what people post and draw your own conclusions if they know what they are talking about or not.....

[Holtzauge]

I mean the Data that is very well documented like Top Speed and Constant Climp Performance and Turn Rate ist not big evidence here.

More things like Parasite Drag in a Turn Flying and Climbing with Flaps deployed AOA  and accelerate are more or less compare later togheter to a Energy Managment how on Earth you can claim this is correct or not?

 

The figures I posted only makes comparisons for hard numbers like speed, climb and turn rate. When it comes to the low speed handling then yes, I'm sceptical as well when it comes to the way popping flaps at low speed is rewarded. In addition when it comes to energy retention, I made the observation that the German planes seem much worse ingame at higher altitudes than my simulations indicate.....

 

However, the point I was trying to make earlier was that it seems to be the F and G 109's, not the Yak that is the most "overmodeled"  in climb......

[LLv34_adexu]

Well depends on what you mean with top level...

 

On a more serious note: I have an MSc in aeronautical engineering and the C++ simulations results I sometimes post are from an extension of a program I coded for my master’s thesis which originally was to determine the effects of external stores on modern jets. And since you asked, I have worked on the AJ37, JA37 Viggen and JAS39 Gripen, both in engineering and in project management. But I’m not claiming to be right because I have an MSc, there are plenty others here in the forum who are quite knowledgeable so as in all other things on the internet you have to read what people post and draw your own conclusions if they know what they are talking about or not.....

 

Oh, Grippen, that is a good reference . Carry on. I hope FiAF won't get em as our next fighters, they somehow get down w/o shooting.

 

On serious note, there is a lot of things which are modeled differently in this game as it should be. I am just wondering why some test data is ignored by developers. I just had good advice from one FiAF engineer to stay away from FM forums. I think I will take his advice. I am just wondering why they did get so bad climb rate to Yak in RL documents, when your C++ says otherwise? Don't bother to answer.

[1PL-Husar-1Esk]

Low speed handling and near/post stall behavior is what concerns me more than few kph more/less at high altitude.

[Holtzauge]

<snip> there is a lot of things which are modeled differently in this game as it should be. I am just wondering why some test data is ignored by developers. <snip>

Those are pretty bold statements: Can you back that up? What should be modeled differently? What data is ignored by the developers?

 

<snip> I am just wondering why they did get so bad climb rate to Yak in RL documents, when your C++ says otherwise? <snip>

What RL documnets would that be? My C++ simulation is nation agnostic and performance is dictated by aspect ratio, aerodynamic cleanliness and P/W and W/S loadings etc. In general, RL data shows quite a big spread so usually you have to look at many numbers to determine anything. You can cherry pick numbers to fit any agenda so I'm assuming you have a bunch of RL documents on the Yak then?

 

[L3Pl4K]

Nice, this topic is turning into a Kindergarten.

[LukeFF]

You are really a bit too optimistic about the FM update. It's a premium plane (pay to win). The view to the back, maneuvering, speed, the weapons, just makes me wonder, what kind of plane Yak-3 was (which my grandfather praised, as he was serving at a/f during the war) if Yak-1b is performing like this...

Ah, the ol' "if a Soviet fighter is competitive, it's obviously overmodeled" argument.

[Finkeren]

You are really a bit too optimistic about the FM update. It's a premium plane (pay to win). The view to the back, maneuvering, speed, the weapons, just makes me wonder, what kind of plane Yak-3 was (which my grandfather praised, as he was serving at a/f during the war) if Yak-1b is performing like this...

The "pay to win" comment pretty much discredits your entire argument (is the Ju 52 "pay to win" too?)

[StG2_Manfred]

Ah, the ol' "if a Soviet fighter is competitive, it's obviously overmodeled" argument.

 

The "pay to win" comment pretty much discredits your entire argument (is the Ju 52 "pay to win" too?)

 

It doesn't discredit him and it is also not about being competitive.

 

https://youtu.be/oobd2_ko4Co?t=3m03s

Edited June 6, 2017 by StG2_Manfred

[DD_Arthur]

Manfred, what do you think of the over-performance of the 109's in BoS?

[LLv34_adexu]

 

Low speed handling and over 10G turns should be somehow fixed. Untill that, game the game.

 

The "pay to win" comment pretty much discredits your entire argument (is the Ju 52 "pay to win" too?)

Well its german plane, given as opposite, fun for Yak-1b owners to something to shoot at.

[Stig]

https://forum.il2sturmovik.com/topic/29541-tacview-161-available-and-working-il-2/?p=477086

 

Don't rely too readily on those numbers Tacview is showing.

[Willy__]

Low speed handling and over 10G turns should be somehow fixed. Untill that, game the game.

 

What boggles my mind is how fast the Yak is able to regain speed while the 109 struggle doing so 

Edited June 7, 2017 by JAGER_Staiger

[Brano]

Please,add that line here,to your wingies enlighted comments and review.

 

 

Edited June 7, 2017 by Brano