549kmh Bf109f2?

[=TBAS=Sshadow14]

You dont need to buy tacview its free to use..

Anyways have you guys tried with HUD on Testing the max speed for an engine mode based on what the hud says and IGNORE RPM and ATA don't think into it too much.
But Game does not care if listed power for combat power is actual 2400RPM @ 1.4Ata All it cares is that hud state is in Combat power.

Eg,
In 111/88/87 you can run @ Rated climb power for 30 mins (2400rpm @ 1.25 ata in 111)
Or you can run at (2480 RPM and 1.295 Ata) for 30 mins and game dont care as long as it says you are in Climb mode then game does not care and it will last 30 mins or 20 mins depending on plane regardless of engine settings.
so you have to look what Hud percentage = what engine specs for a given speed (IGNORE ATA and RPM listed in Real manuals and fly by %% and HUD Labeling and retry test.)

Or you can run take off mode but if you climb steep the reduced airflow over engines kicks them back to Climb mode even tho engines on take off settings.
so with those take off settings i can run 30 mins climbing steep (for reference with care 111 can run 30 mins of 89% power n 90% prop (or 2495 RPM and 1.299 ata GAME DOES NOT CARE As hude says CLIMB MODE)

Edit: im curious so ill check out what settings are max power for each hud state. (must ignore RPM and ata its meaningless)

 

Edited May 22, 2017 by =R4T=Sshadow14

[Boaty-McBoatface]

Finkeren, Mig 3 will do 525 with near closed rads every time. Seems accurate with the devs stats this one but anyway that's another topic.

 

So 5tuka gets the same incredible speed results as me. 548kph on the deck in an F2 with DB601N. Raising the RPM it will get 549 as per OP. This seems ridiculous speed to me. Some very suspect power coming out of the old N model there. My test conditions were exactly the same but at 300m alt.

 

And on that point, why would the Dev stats be 528kmh@1175hp for the F2 and 522kmh@1200hp for F4? 25 more HP and the F4 with near identical airframe is 6kmh slower. Must be something we're missing here?

Edited May 23, 2017 by B0SS

[Willy__]

And on that point, why would the Dev stats be 528kmh@1175hp for the F2 and 522kmh@1200hp for F4? 25 more HP and the F4 with near identical airframe is 6kmh slower. Must be something we're missing here?

 

The propellers are different. 

Edited May 23, 2017 by JAGER_Staiger

[=TBAS=Sshadow14]

Ok if this is not intended then there is a bug maybe.

Finally had time so i just tested this in 109 - F2 (clean plane, no weapons, 60% fuel-rear tank empty) quick mission @ 300m no weather calm 13:00
You lot already know the rated combat mode specs for F2 but just in case
(Combat power (up to 30 minutes): 2400 RPM, 1.25 ata)

Here are the settings i just ran for 23mins before i got bored as i dont really fly fighters (Auto level non stop cruise @ 300m with -100% Nose down Stabilizer Trim - Pic taken around 12 minute mark
ATA: 1.305
RPM: 2500
PITCH: Manual 52%
RADS: Auto


Also Curiously in this pic below i only changed 1 setting(state) of the plane and i bet Nobody can guess what it was to change to these readings.
They just don't make sense.


 

Edited May 23, 2017 by =R4T=Sshadow14

[Finkeren]

From game data:

 

MiG-3 series 24

 

Maximum true air speed at sea level, engine mode - Boosted: 525 km/h

Maximum true air speed at sea level, engine mode - Nominal: 493 km/h

Maximum true air speed at 7600 m, engine mode - Nominal: 626 km/h

 

I reached similar results in game ( autum map +15 deg) with no problem prolonged flight without overheating. If you cant probably you are doing something wrong.

Ok, will have to speed test it again, when I get the chance.

 

My point is: The MiG-3 does 490 km/h on the deck in boosted mode with radiators open (which apparently is how it was tested) so it doesn't seem to be too fast.

[StG2_Manfred]

Kwiatek wrote 'prolonged flight without overheating'. If he's right then it means she's too fast. Either too fast or the overheating is modeled poorly. In real life they opened the radiators for a reason. What is the difficulty to understand this.

[Finkeren]

Kwiatek wrote 'prolonged flight without overheating'. If he's right then it means she's too fast. Either too fast or the overheating is modeled poorly. In real life they opened the radiators for a reason. What is the difficulty to understand this.

It's not hard to understand. Maybe the cooling is too generous on the MiG? That might well be. But its performance seems perfectly fine. If you fly it with radiators open (as was done during testing) the speed matches the source material - ergo, it is not too fast.

 

If you want to make the case, that the Mikunin engine is too easy to keep cool, that's a completely different matter and might well be worthy of discussion.

[StG2_Manfred]

Yeah, and if you fly the F2 with a brake chute it performs within the margins as well.

[Finkeren]

Yeah, and if you fly the F2 with a brake chute it performs within the margins as well.

Sigh....

 

Not even worth getting into this.

[StG2_Manfred]

Sigh....

 

Not even worth getting into this.

Why? I particularly went down to your level!

[Boaty-McBoatface]

Please try keep this on topic lads. Migs are another topic.

 

The problem here is the F2 not performing by the devs specs. An F2 shouldn't reach 549kmh with the old 601N model.

 

1175Hp reaching 528kmh, F4 at 1200hp only reaching 522kmh with a smaller diameter propeller doesn't add up either.

 

Cheers.

Edited May 23, 2017 by B0SS

[19//Moach]

there is also the known and acknowledged fact that in lack of the proper specs for the VDM propeller at the time it was made, the BoX 109's were "fitted" with the same propeller as the Yak

 

 

and apparently, that causes "magic"

 

 

this is one prime suspect for the cause of the 109s uncanny ability to prop-hang in ways that would have had their historical counterparts spinning like a cinder block in a tumble dryer - it's odd that it would cause it to also overspeed at the opposite end of the speed envelope....

 

AFAIK, the Yak propeller is more of a low-speed design than the VDM, which means the latter should have more "oomph" at higher speeds at the expense of static thrust (i.e. longer takeoff run, not ideal for turn fighting)

 

it is then not very logical to suppose that this would be the reason for it overspeeding

 

 

it may then be so that there's more to the puzzle here

 

 

 

anyways, the whole F series has all the signs of being a "first generation" plane, as far as the IL2 fleet is concerned, which means it was made around some aspects of the core simulation that have since been revised - I reckon this is just one of the many reasons they're having to rework all the flight dynamics now

 

 

also, please keep the forum-warrior comparisons away from this board -- the ONLY valid reason for FM revisions is historical accuracy -- this is NOT a board for lobbying the devs to "nerf/buff" one plane or another for "balance" - any comments to that end are thus purely detrimental to the purpose of this forum and even the whole premise of the game

 

 

anyone who then refutes "<plane> shouldn't be able to do <thing it does>" with comments such as "but <enemy plane> does <other thing it maybe shouldn't do>" - is more than welcome to leave and go find a game where the main premise is NOT realism

Edited May 24, 2017 by 19//Moach

[=TBAS=Sshadow14]

how are you getting 548 out of the F2?

what alt & settings

[Boaty-McBoatface]

On my OP and 5tuka's test you'll see 548/549 on 760mmHG no wind at 300m auto level, stabilizer down, full power. It will get 549 on 2800rpm and it will blow.

 

Even on the devs official stats of 528@1175hp 1.35ata, it will far exceed the quoted 528kph. Why is this faster than a F4 with 25 more HP is a mystery.

Edited May 24, 2017 by B0SS

[novicebutdeadly]

From what I read in one book (confirmed by wiki which may or may not mean anything),

 

The F-2 had the DB601N which produced 1,158.9 hp at sea level unknown RPM

 

The F-4 had the DB601E which produced 1,331.5 hp at sea level 2700RPM

 

As an aside just under a third of the circa 1841 F-4's built were the F-4/Z which had a nitrous oxide boost system for high altitude.

 

 

 

Edited May 24, 2017 by novicebutdeadly

[6./ZG26_5tuka]

From what I read in one book (confirmed by wiki which may or may not mean anything),

 

The F-2 had the DB601N which produced 1,158.9 hp at sea level unknown RPM

 

The F-4 had the DB601E which produced 1,331.5 hp at sea level 2700RPM

 

As an aside just under a third of the circa 1841 F-4's built were the F-4/Z which had a nitrous oxide boost system for high altitude.

 

Although this may derail the topic, it seems that the Warthunder Mig 3 is more accurate in terms of 2 main features:  

 

It doesn't have canons (these were fitted by some pilots much later in the conflict) and no slats as they were never fitted to production aircraft.

Don't know where your figures come from so I'll go by original manufacturer data:

 

DB601N

 

DB601 E:

 

 

how are you getting 548 out of the F2?

 

what alt & settings

Shouldn't be difficult to find out for anybody with the ability to read.

Edited May 24, 2017 by 6./ZG26_5tuka

[303_Kwiatek]

DB601N used in F-2 power rating

[novicebutdeadly]

Don't know where your figures come from so I'll go by original manufacturer data:

 

DB601N

 

DB601 E:

 

 

Shouldn't be difficult to find out for anybody with the ability to read.

Interesting power graph for the 601E, is there one that shows how the Nitrous Oxide improved the performance (at altitude)?

Edited May 24, 2017 by novicebutdeadly

[Boaty-McBoatface]

I made a finding with the F models. If you run F2 at default stabilizer setting (I think -45%) it will get exactly the Devs figure of 528kmh@1175hp 1.35ata.

 

Similarly F4 gets 522kmh@1200hp 1.3ata.

 

This accords with the official dev claims. Problem is there's an inconsistency with the other BF's as the figures for those other planes don't seem to agree with the in-game performance at same default stabilizer positions (too slow, only reach near these claimed speeds at maximum negative stabilizer)

 

2 questions remain:

 

1.How did the devs come up with these speed claims, because the in-game speed is too high on full negative stabilizer.

 

2. How is the F2 this much faster with less power than the F4.

F2- 528kmh@1175hp

F4- 522kmh@1200hp

Edited May 29, 2017 by B0SS

[303_Kwiatek]

F4 could have different prop optimized for higher alt performamce?

[Finkeren]

F4 could have different prop optimized for higher alt performamce?

 

Yep, and a larger chin radiator and supercharger intake. That could easily account for that small difference. 

 

The bigger question is: Why does the adjustable stabilizer provide such a huge speed boost? You'd think that during the real life testing of the Bf 109, they would have trimmed it to fly straight and level.

Edited May 30, 2017 by Finkeren

[=EXPEND=Tripwire]

Anyone know what stabilizer settings were used in actual speed tests? For max speed tests when performed by the Germans were they using full negative stabilizer?

You'd think that during the real life testing of the Bf 109, they would have trimmed it to fly straight and level.

 

Agreed.

[Finkeren]

I'm not sure trim settings were recorded. They'd just trim the aircraft for level flight, same as a pilot would normally do.

[Jizzo]

Not 100% sure, but i think they used fully nosedown stab settings during german tests.

 

If i am not mistaken even the manual says, to achieve max speed in the 109 fully nosedown stab is required.

Edited May 30, 2017 by [TWB]Jizzo

[Finkeren]

Not 100% sure, but i think they used fully nosedown stab settings during german tests.

 

If i am not mistaken even the manual says, to achieve max speed in the 109 fully nosedown stab is required.

Can you locate a source for this? That might be all the proof that's needed to show that the F2 speed is wrong.

[JG13_opcode]

An aircraft is fastest when it's in trim, so if every aircraft in the sim is fastest at full negative stab, I think that that is a bug.

[Finkeren]

An aircraft is fastest when it's in trim, so if every aircraft in the sim is fastest at full negative stab, I think that that is a bug.

Unless full negative is the setting that's "in trim" at maximum power and airspeed?

[6./ZG26_Klaus_Mann]

An Aircraft is at it's fastest if it doesn't Slip and the Control Surfaces are in-Line with their Stabilizers. Flying straight and Trimmed in a 109 the Elevator is always Pointing Downwards inducing Drag. 

It Produces the smallest Drag when the Stabilizer is Pointing fully Upwards which means the Elevator is fully inline with the Stab thus Producing the Littlest Drag. 

A Flettner Trimmed Aircraft when the Flettner Tab is Flush with the Surface, ingame that would be 0% for ALL. However, depending on Weight Distribution you have to Push or Pull to Maintain Straight Flight. 

 

That's why Modern High Performance Gliders use either Spring Loaded Trim which works Mechanically, not Aerodynamically or All-Flying Tails.

 

Flettner on the Left, All Flying on the Right.

 

 

 

Adjustable Stabilizer as on Bf109 which Works by Moving the Leading Edge up and Down.

 

 

 

Spring Loaded Trim (as in Ju-52 Rudder)

 

[JG13_opcode]

Unless full negative is the setting that's "in trim" at maximum power and airspeed?

True. However from an aircraft design perspective it's unlikely that this was historically the case. If full negative trim was required for maximum level speed, you would not be able to trim it for a dive.

 

Edit: spelling

Edited June 1, 2017 by JG13_opcode

[JtD]

According to the Soviet tests of a 109G, a tailplane with 1.5 degrees nose heavy trim still requires around 2 degrees of nose down elevator at high speed for level flight at combat power.

 

The German dive test documents posted on this forum a couple of times mention a 1.0 degree position in nose down direction for cruise, with a trend towards nose up as speed increases, necessitating more nose down trim.

 

The trim range of the tailplane was limited to 2 degrees in the nose heavy direction.

 

So the trend for a maximum nose heavy trim for high speed level flight is correct. It could be a matter of individual aircraft characteristics, some probably needed the maximum trim, some probably didn't, and this BoS doesn't model.

Edited June 3, 2017 by JtD

[novicebutdeadly]

According to the Soviet tests of a 109G, a tailplane with 1.5 degrees nose heavy trim still requires around 2 degrees of nose down elevator at high speed for level flight at combat power.

 

The German dive test documents posted on this forum a couple of times mention a 1.0 degree position in nose down direction for cruise, with a trend towards nose up as speed increases, necessitating more nose down trim.

 

The trim range of the tailplane was limited to 2 degrees in the nose heavy direction.

 

So the trend for a maximum nose heavy trim for high speed level flight is correct. It could be a matter of individual aircraft characteristics, some probably needed the maximum trim, some probably didn't, and this BoS doesn't model.

Does that inverse as it comes closer to compressability?

[JtD]

Does that inverse as it comes closer to compressability?

The push forces decreased and could become pull forces at speeds above about 500km/h IAS, 700km/h TAS or Mach 0.75.

[Panthera]

Would just like to add that you should be getting the max speed with automatic prop pitch enabled, that's how the German tests were conducted. So why is everyone running manual pitch?

[SJ_Butcher]

What did you get Finkeren? Autumn, ISA, 300m start altitude, maximum negative stabilizer, full throttle F2 until engine blows. 549kmh, I couldn't believe it myself. I did it multiple times. It is insanely fast for a DB601N with far less power than a F4 or G4. 

remember that F2 is lighter than other planes

[Bilbo_Baggins]

remember that F2 is lighter than other planes

True the F2 is slightly lighter by 100kg but this is actually irrelevant. Not only is the weight difference so small, but weight doesn't play any significant part in top speed whatsoever.

 

Weight affects acceleration but top speed is a relationship between drag and power.

 

Decrease fuel by 100kg and the top speed stays the same. Acceleration and climb will improve though.