Author Topic: how about MW-50 and or GM-1 for the Dora?  (Read 1085 times)

Offline Soviet

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how about MW-50 and or GM-1 for the Dora?
« on: May 30, 2002, 08:36:44 PM »
the current AH Dora has no MW-50 system I think it should be added.

The following values are the most commonly used figures in most publications and match captured German test charts using a standard Fw190D-9 using Takeoff-Emergency power, using B4 / 87octane fuel, with a Jumo 213A-1 in May 1944. There is confirmation that this was without MW50.

This gave the following speeds (without MW50)
357 MPH (sea level)
397 MPH (10,830 ft)
426 MPH (21,650 ft)
397 MPH (32,800 ft)
From: http://jagdhund.homestead.com/files/Dora.htm

"The addition of a "Ladedruckssteigerungs-Ruestatz" increased output from 1750 to 1900PS without an additional boosting agent such as MW-50 or GM-1. This could be used below 5000m and with the addition MW-50 gave an Emergency output of 2100PS. In addition, this enabled the previous Emergency power setting of  to be maintained for 30 min on the deck and The climb and Combat power setting (1620PS) to be maintained indefinitely. This "Ruestatz" was in  use with III/JG54 in October '44 and was in wide spread use with three other Jagdgeschwader by December '44"

"There are 5 speed curves represented on captured Focke-Wulf Flugzeugbau G.M.B.H. graphs available from the Smithsonian Institution. I have included additional tables for the use of GM-1 not represented on the
graphs from the Smithsonian but verified from U.K. documents. There is no known evidence that specifically states that GM-1 was used on the D-9 operationally but it was certainly possible and system tests were done with performance verification. All these graphs and numbers are for a Fw190D-9 at it's normal loaded combat weight ( 4,270 kg ) which includes; (2)MG131 (13mm) and (2)MG151/20 (20mm) guns along with the ETC 504 ordnance rack. "

Power setting Translations;

1) Start -u. Notleistung - Takeoff & Emergency
Emergency power (i.e. take off or emergency)   The Jumo 213 A-1 had a normal takeoff power of 1285kw (1750PS). A power output could be achieved, through a conversion kit, of 1395kw (1900PS) with increased boost pressure up to flight altitudes of 5000meters. The past takeoff performance (1750PS at ground level) could now be used for 30 minutes, and combat performance (1620 HP at ground level) became certified for continuous duty. This is the first sufficient measure to be corresponded that met the desires of the pilots for increase in output.   With the "Ladedruckssteigerungs-Rüstatz" this becomes 1900ps, sustainable for 10 minutes.


2) Sonder - Notleistung - Special Emergency
I beleive this power setting is the similar in principle to the Fw190A using "Erhöhte Notleistung" with C3 injection. That is, bleeding of the airline of the blower to induce a petrol surge and use it as a charge cooler. The setting was the same as in the A-8. There was a button, or lever, on the control panel to open the valve. To summarize, it was a petrol injection in the eye of the blower. It had the effect of allowing increased boost by its charge-cooling effect.  It could only be used at full speed and 3,250 rpm. It was usable for 10 minutes, This power curve is listed with C3 fuel. I do not yet have a power curve to verify engine output in this configuration but it would be greater than 2100PS based on the speed and climb curves.
After the use of this Special Emergency power, no form of Emergency power could be used for at least five minutes

3) Sonder - Notleistung mit A Lader als Bodenmotor
Special Emergency power with compressor as the base-engine I am not really sure what this means.
I have viewed a chart that lists a similar power setting with a Ladergang which I believe is a special low altitude compressor gear. This may have been a rare engine/blower combination. Maybe not? I have no idea how many aircraft actually had this "power egg" or blower gear but the chart lists it's use. I have speculated that the Dora "Red 13" of JV44 may have had one of these engines. I do not have a engine power curve for this setting but based on the numbers it must have produced a significantly higher power than 2100PS at low altitude. This may be the 2240PS power setting?


4) Sonder - Notleistung mit Ladedruckerhoehung mit MW50 u. 1.8 ata. Special Emergency Power (with MW50)  2100PS at 3,250rpm, MW-50 at 150 l/h and B4 at 800 l/h.

Maximum power with MW50 was 2,100 hp at 3,250 rpm and was not to be used above 16,500ft. (around 5000 meters). In any case, the RAE tested the Jumo 213 A-1 with MW50, and at 21,000ft the engine
produced 1680 hp instead of the 1600 hp. At that altitude the output is the same whether you are using Takeoff & Emergency or Special Emergency power. This power setting was to be used for 10 minutes then 5 minutes at normal power before used again. The engine power chart also shows a dashed line at  2,240PS. I am not sure if this applies with B4 fuel.

5) Steig - u. Kampfleistung-Climb & Combat

This could be maintained for 30 minutes. With the "Ladedruckssteigerungs-Ruestatz" this power could be maintained indefinitely. Combat and Climb power covers the same principle as in any other plane. This is similar to what the UK documents have found: 1680 ps @ 3000 rpm

http://jagdhund.homestead.com/DoraCharts.html


Offline GRUNHERZ

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how about MW-50 and or GM-1 for the Dora?
« Reply #1 on: May 30, 2002, 09:19:37 PM »
Just to alert everyone the 640 km/h speed on the deck translates to 398mph. FW190D9 at 398mph on the deck, go to hell Tempest!

This version could certainly be another worthy AH German perk fighter.

Offline Soviet

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how about MW-50 and or GM-1 for the Dora?
« Reply #2 on: May 30, 2002, 09:32:22 PM »
perk worthy is correct if it's 400 on the deck but unless it gets 4 hazookas i wouldn't make it too steep.  Say 15 perks since it's fast on the deck but not very manueverable (hell a p-51 outturns it i've even had jugs outturn my dora)

On a totally unrealated matter I propose bringing perk values down.

Me-262- 100 perks, (200 is a bit steep, i mean i can afford a few of them at 200 but what about your average Newbie or someone who can't spend a lot of time on AH?)

Tempest- 25 perks, it's good and has 4 super-lazer guns and would be able to outturn the "super" version of the dora

F4u4- 15 perks, This fighter isn't even worthy of it's extremly expensive perk, it deserves to be cut down drasticly

SpitXIV- 20 Perks, it's good but come on it doesn't justify the level of perking it received.

Ar-234- Fine, just make it so you can aim the 20mm.

Ta-152- the current 20 is good but still i'd like to see it a bit lower say 15 or even 10.  It's good high up but unless you climb past 35k it really isn't gonna do much.  All it's good for is going up to 40k and cherry picking bombers that are below you.

F4u1c- Fine, judging from the current stats it does fairly well and it's cheap perk cost allows little frustration when losing it.  I think 10 is a perfect balance.

Offline Karnak

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how about MW-50 and or GM-1 for the Dora?
« Reply #3 on: May 30, 2002, 09:32:36 PM »
Soviet,

The AH Fw190D-9 has MW50. I don't know if it has GM1 though.

Do some searches on this subject in this forum and the gameplay forum.  It has been discussed in great detail.  As I recall the conclussion was that the version you are posting about was a different version than the one we have, which is a different version than the one WB has.  They are all Fw190D-9s though.  Be glad ours has MW50.  WB version does not (at least not back in the 2.x days).
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Offline Soviet

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how about MW-50 and or GM-1 for the Dora?
« Reply #4 on: May 30, 2002, 09:35:44 PM »
Well also from the stats of the Dora I believe it has B4 fuel, it would be nice to have the variant with C3 fuel since it was more common in the latter part of the war.  I still think the P-51 would be faster so you runstang pilots don't have much to fear. and the dora really isn't that manueverable so it isn't too much of a threat with the C3 fuel

Offline HoHun

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how about MW-50 and or GM-1 for the Dora?
« Reply #5 on: May 30, 2002, 10:01:22 PM »
Hi Soviet,

from my analysis of the Fw 190D-9's performance, I'm certain that curve 3 in the diagram you posted is the one for the 2140 HP branch of the Jumo 213A engine (using B4 fuel and MW50 injection). I reckon 2140 HP are achieved by using supercharger high gear from sea level up. (There's a Jumo 213A engine chart showing the low gear branch as well, which would result in another 100 HP, but apparently it was not practically usable.)

Curve 4 is for the 1900 HP branch of the Jumo 213A engine, which depending on the aircraft's configuration seems to have been achievable with or without MW50. Accordingly, it would be more accurate to consider the Aces High Fw 190D-9 a "1900 HP Dora" than a "MW50 Dora".

(Speeds could be expected to be another 10 km/h higher without the bomb rack, by the way.)

Regards,

Henning (HoHun)

Offline Naudet

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how about MW-50 and or GM-1 for the Dora?
« Reply #6 on: June 02, 2002, 03:57:14 AM »
As i stand in constant contact with Brian (who made this website) and from own researches i know the following:

GM-1 was never used in an operational D9, there were test with GM-1 but no operational aircraft ever used it.

The A-Lader in Curve 3(the curve which gives 398mph/SL) was rare, so far there is just the guess that Klaus Fabers D9 of JV44 had such an engine, it would be a fun addition, but as above with GM-1 operational used is questionable.
At the moment, no information about the power output is really available.


Curve 4 must be a 2100-2240 PS (not HP) this is confirmed from a JUMO213 chart.

The 1900PS setting was one without MW50, it was possible through a Ladedrucksteigerungsrüstsatz (boost pressure increase kit).


@HoHun: Ich kenn ja die Rechnung die du vorgenommen hast, Problem ist nur immer noch, das wir den Propellerwirkungsgrad nicht kennen. Das kann die Ergebnisse verfälschen.

Offline Sachs

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how about MW-50 and or GM-1 for the Dora?
« Reply #7 on: June 02, 2002, 10:22:16 AM »
Naudet.  When I was reading the JV44 book, I was under the assumption that all the Doras were souped up?  They went into combat reckless thinking/knowing they had a fast as hell Dora.  I know that Sachsenberg would go into combat fearing nothing.  And with his tally of kills he was no slouch either :)  Wondering what was done to those doras to make them faster?  Any ideas?  Is the stats they show on this chart the doras that were used?  What about stats for the D-11 they also flew?  Anyone have stats on it?

Offline Vermillion

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how about MW-50 and or GM-1 for the Dora?
« Reply #8 on: June 02, 2002, 11:45:34 AM »
Sachs, it may well be true that JV44 was well known for "souped up" Dora's, just as the 56th FG was well known for modifying their P-47C's and D's to perform well beyond what the factory planes could do.

But to be consistent, HTC has to have a rule on what they use to model their aircraft.  And basically the rule is to use factory performance numbers, not locally modified aircraft.

Offline HoHun

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how about MW-50 and or GM-1 for the Dora?
« Reply #9 on: June 02, 2002, 12:16:20 PM »
Hi Naudet,

>Curve 4 must be a 2100-2240 PS (not HP) this is confirmed from a JUMO213 chart.

Curve 4 makes no sense as 2100 or 2240 HP chart. The 2100 HP branch is a smooth curve without any supercharger gear change "step" in it, just like curve 3.

>@HoHun: Ich kenn ja die Rechnung die du vorgenommen hast, Problem ist nur immer noch, das wir den Propellerwirkungsgrad nicht kennen. Das kann die Ergebnisse verfälschen.

Propeller efficiency doesn't change the relation between the different curves, and the Jumo 213A power curves match the Fw 190D-9 speed curves very well, including the 2100 HP branch and curve 3.

Regards,

Henning (HoHun)

Offline Naudet

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« Reply #10 on: June 02, 2002, 04:54:14 PM »
HoHun, i will answer in german, as i would not get it right understood in english:

Ich kenn das Problem, hatten wir ja damals auch schon. Wenn man die Kurven miteinander vergleicht, fragt man sich woher den die unterschiedlichen "Zacken" in der Kurve kommen.

Wenn man nur die Laderstufenumschaltung des JUMO213 Blattes mit dem Geschwindigkeitsgraphen vergleicht würde es wie folgt aussehen:

Kurve 4 = Start- u. Notleistung aus JUMO 213 Blatt
Kurve 3 = Sonder -notleistung aus JUMO 213 Blatt, ohne den 1. Ladergang, da nur so der gerade Verlauf von Kurve 3 erklärbar ist
Kurve 5
Kurve 1 = Steig- u Kampfleistung (1700PS) aus JUMO 213 Blatt
Kurve 5 = würde zur "alten" Steig u. Kampfleistung (1620 PS) passen, die bei Motoren mit Ladedrucksteigerungsrüstsatz als Höchszulässige Dauerleistung freigegeben wurde, allerdings findet sich keine passende Stufe im JUMO213 Blatt

Allerdings habe ich folgende Bedenken:

1. Wenn Kurve 3 mit MW50 erreicht würde, und man der Sondernotleistungkurve im JUMO213 Blatt folgt, dürft die Kurve 3 im Geschwindigkeitsdiagram nicht unter der Kurve 4 in größeren Höhen liegen, da ihre Leistung im JUMO213 Blatt nahtlos übergeht
2. Es ist nicht sicher ob die JUMO213 Blattdaten genau mit denen eines D9 JUMO213 übereinstimmen, möglicherweise wurden andere Laderstufenwechsel benutzt (vergl. mit Spit XIV Prototyp und Spit XIV Serie, da haben sich die kritischen Höhen geändert)
3. Da ich Diagramme von echten Produktionsmaschinen gesehen habe, ist die Möglichkeit das Kurve 4 mit 1900PS erreicht wurde sehr gering
4. Da die Beschriftung der Kurve 4 unzweideutig ist, und diese meinem jetzigen Wissensstand zufolge daher 2100PS bringen muss.


Aber folgende Sachen sind noch nicht richtig geklärt:

1. Was ist der A-Lader? Er könnte durchaus die von Rodeike beschriebene "vollständige MW-50" Anlage (wahlweise Kraftstoff-/MW-Betrieb) sein, die 2100PS am Boden leistet

2. Was genau ist der Ladedrucksteigerungsrüstsatz? Ist er wirklich "nur" eine Ladedrucksteigerung, oder ist er das vereinfachte MW-50 System Oldenburg(ohne wahlweisen Betrieb), da er (auch wieder nach Rodeike) auch über den MW-Schalter bedient wurde. Das würde bei Kurve 4 den Eintrag "mit MW-50" erklären.

3. Sind beide wirklich nur unterschiedliche MW-Anlagen, die aus irgendeinen Grund (Druck, Einspritzung etc,) andere Steigerungen bringen, dann ist die Annahme das Kurve 3 für die vollständige MW-50 Anlage gilt und das Kurve 4 für die vereinfachte MW-50 Anlage Oldenburg gilt, sehr wahrscheinlich richtig.

Offline HoHun

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« Reply #11 on: June 03, 2002, 06:01:53 PM »
Hi Naudet,

>1. Wenn Kurve 3 mit MW50 erreicht würde, und man der Sondernotleistungkurve im JUMO213 Blatt folgt, dürft die Kurve 3 im Geschwindigkeitsdiagram nicht unter der Kurve 4 in größeren Höhen liegen, da ihre Leistung im JUMO213 Blatt nahtlos übergeht

Remember the Jumo 213A chart is for the engine alone, but the speed curves are for the complete aircraft. For example, a change in the supercharger air intake geometry to get the full 2100 HP at low altitude might reduce ram air pressure enough to get the slight difference at high altitude evident from the speed chart you're referring to.

>2. Es ist nicht sicher ob die JUMO213 Blattdaten genau mit denen eines D9 JUMO213 übereinstimmen, möglicherweise wurden andere Laderstufenwechsel benutzt (vergl. mit Spit XIV Prototyp und Spit XIV Serie, da haben sich die kritischen Höhen geändert)

If you don't look just at the supercharger gear change altitudes, but at the complete power and speed curves over altitude, you'll see that the curves match well all over the altitude range, not just at the critical altitudes.

>3. Da ich Diagramme von echten Produktionsmaschinen gesehen habe, ist die Möglichkeit das Kurve 4 mit 1900PS erreicht wurde sehr gering

I'd like to see those diagrams :-)

>4. Da die Beschriftung der Kurve 4 unzweideutig ist, und diese meinem jetzigen Wissensstand zufolge daher 2100PS bringen muss.

As far as I can tell, you're relying entirely on the "MW50" appelation in the speed chart to motivate the 2100 HP figure. However, the Jumo 213A underwent an evolution that makes MW50 an unreliable indicator for engine power.

>1. Was ist der A-Lader? Er könnte durchaus die von Rodeike beschriebene "vollständige MW-50" Anlage (wahlweise Kraftstoff-/MW-Betrieb) sein, die 2100PS am Boden leistet

"Lader" means "supercharger". "Bodenmotor" means that the engine was configured to provide maximum power at sea level, in this case by using the "A"-type supercharger. Since the Jumo 213E differed in the supercharger, I'd say the "A"-type supercharger was the Jumo 213A's standard supercharger - operating in high gear from the ground up.

(I'll skip the rest of your questions as they address the MW50 question, which -  as outlined above - I consider secondary.)

Regards,

Henning (HoHun)

Offline Naudet

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how about MW-50 and or GM-1 for the Dora?
« Reply #12 on: June 04, 2002, 02:06:24 AM »
About the MW50 indications:

The evolution of the JUMO213 (as i know it) looks like that:

JUMO213 basic:

1750PS Start- u. Notleistung (WEP) up to 3 mins
1620 PS Steig- u. Kampflesitung up to 30 mins


JUMO213 with Ladedrucksteigerungsrüstsatz:

1900 PS  Start- u. Notleistung up to 10 mins
1700~1750PS Start- u. Notleistung now up to 30 mins
1620PS Steig- u.  Kampfleistung now indefinitely


JUMO213 with complete MW50 system:

2100PS Sondernotleistung up to 4x10mins
1900 PS Start- u. Notleistung
1700~1750PS Start- u. Notleistung now up to 30 mins
1620PS Steig- u.  Kampfleistung now indefinitely


And cause of this evolution i can't consider the MW50 question secondary, if the Ladedrucksteigerungsrüstsatz used MW50 than i fully support and accept that curve 4 is very likely for 1900PS.
But if it DIDNOT use MW50 than it is impossible that curve 4 is for 1900PS.

I think if i can find out more about the Ladedrucksteigerungsrüstsatz, the Oldenburg MW50 System and the complete MW50 System, than this question can be definitivly answered.

P.S.: Mit den Datenblättern ist's so ne Sachen, schick mir mal ne Email dann erklär ich's dir.
« Last Edit: June 04, 2002, 06:29:11 AM by Naudet »

Offline HoHun

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« Reply #13 on: June 04, 2002, 01:24:35 PM »
Hi Naudet,

>And cause of this evolution i can't consider the MW50 question secondary, if the Ladedrucksteigerungsrüstsatz used MW50 than i fully support and accept that curve 4 is very likely for 1900PS.
But if it DIDNOT use MW50 than it is impossible that curve 4 is for 1900PS.

You're trying to match individual data points. I matched the entire speed graphs. It's like matching fingerprints - they might be a bit distorted and incomplete, but they allow no doubt about who left them.

The Jumo's 2100 HP power graph doesn't resemble curve 4 the slightest bit, but if you use it to calculate speed over altitude, it coincedes very well with curve 3.

Regards,

Henning (HoHun)

Offline Naudet

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« Reply #14 on: June 05, 2002, 04:07:31 AM »
Yes, i see what you mean, and i slowly get an idea how it works.

Has something to do with boost pressure.
And also after re-thinking a few things, it might well be possible that a late JUMO213 with "vollständiger MW-50 Anlage" might deliver the 1900PS without using MW50.

Here is how i think it works.

The main difference between Oldenburg MW-50 System and the complete system is, that Oldenburg can only be used with MW50 while the complete MW50 System allows to change between fuel and MW50 usage.

Also the Oldenburg was a low pressure MW50 system, while the complete MW50 system was a high pressure one.

Assuming this, the following might be possible:

JUMO213 with Oldenburg:
1900PS with "low pressure" MW50 for 10 mins

JUMO213 with complete MW50 system:
2100PS with "high pressure" MW 50 for 10mins
1900PS with "high pressure" fuel injection

that would explain why in the JUMO213 chart the 1900PS curve just uses B4 fuel, cause those powercurves must be for a JUMO213 using the complete MW50 system, otherwise it would never deliver 2100+PS on MW50.

Btw, we don't excatly know which JUMO213A Variant was used in the speedcalculations
and the JUMO213 powerchart is also not clearly labbeled.
Might well be the possibility that a JUMO213 with different charateristics was used for the calculations.

It's really hard that we can't ask the guys who recorded those charts what they were for. :)