DB 605A-1 1.42 ata (WEP) duration

[41Sqn_Skipper]

1 hour ago, VO101Kurfurst said:

...

 

Thanks, finally something useful. So 3 minutes is the limit for C3 fuel. Question remains for B4 fuel, but a limit of 5 minutes, 10 minutes or unlimited time for 1.42 with B4 is unlikely.

 

From the MW 50 manual:

"Bei Verwendung von B4-Kraftstoff darf keinesfalls (...) mit Sondernotleistung weitergeflogen werden."

Between the lines we can read that with C3 fuel some use of more than 1.3 ata is acceptable, but not so when B4 fuel is used.

 

So we have the documented limits:

• 1.42 ata for 3 minutes with C3 fuel
• 1.42 ata for 1 minute with B4 fuel; however it was blocked for several time periods.

 

 

[CUJO_1970]

22 hours ago, LColony_Red_Comet said:

Come off it.

You know full well that reading a MAP gauge is not the same as the issues with measurement errors that occurred in pitot tube as mach numbers increased. Not to mention that by your own logic we should also disregard pilot anecdotes of operating the engines within the limits...in fact, if you think the MAP guages were unreliable, its a wonder how anyone could think the pilots maintained MAP timers or even MAP limits since the gauges were too unreliable to tell lol! I mean how do we know their clocks even worked?

 

Find better sources that don't contain excessive fiction. That will help make your point more credible.

[Kurfurst]

8 hours ago, 41Sqn_Skipper said:

 

Thanks, finally something useful. So 3 minutes is the limit for C3 fuel. Question remains for B4 fuel, but a limit of 5 minutes, 10 minutes or unlimited time for 1.42 with B4 is unlikely.

 

Why ‘unlikely’? Why would be there different limitations for different fuels?

 

Fact is the Allies found a a G14 (factory MW converted G6/U2 given the serial) and it had 3 minute markings for 1,42 ata boost on its dashboard. Just like cocpit pictures of F4s posted earlier.

 

8 hours ago, 41Sqn_Skipper said:

 

From the MW 50 manual:

"Bei Verwendung von B4-Kraftstoff darf keinesfalls (...) mit Sondernotleistung weitergeflogen werden."

Between the lines we can read that with C3 fuel some use of more than 1.3 ata is acceptable, but not so when B4 fuel is used.

 

 

There is no such thing about fuel in any manual or document listed I have seen. And I have seen a few.
 

8 hours ago, 41Sqn_Skipper said:

So we have the documented limits:

• 1.42 ata for 3 minutes with C3 fuel
• 1.42 ata for 1 minute with B4 fuel; however it was blocked for several time periods.

I don’t quite see from where you get this 1 min for B4, 3 mins for C3 theory.
It is not listed in any manual as such, and it does not make any sense from the technical POV. Perhaps later spark plugs had something to do with it but thats speculation. Fuel definitively did not, either you have knocking or you don’t, and B4 was perfectly happy at 1,42 on all previous DBs (and in fact up to 1,5 on the later D series).

 

The MW 50 manual certainly does not say what you see implied. It says you cannot use Special emergency (Sondernotleistung), that is, 1.7 ata and above with B4 without MW injection. This is perfectly logical since the engine had to run in first and then set up for MW operation, including different throttle movements. Without MW your throttle gave 0,8-1,3 ata in the 0-100% movement range, and 1,42  ata at the 110% range, i.e. it was perfectly linear. With MW the setup was changed,  the first 0% - 100% of movement still controlled the throttle control the 0,8-1,3 ata boost region, but the last tiny 100% to 110% added almost the same boost, a whopping 0,4 ata boost to that on very little physical movement. You could very easily over-stress the engine using a rating beyond 1,42. B4 was perfectly capable of handling 1,42 ata, but not much beyond. C3 could go up to 1,8 even without MW without knocking though thermal load of the spark plugs without the cooling effects of MW could be an issue if persisted for  too long, even if there was no knocking issue with the fuel itself.

[the_emperor]

3 hours ago, VO101Kurfurst said:

The MW 50 manual certainly does not say what you see implied. It says you cannot use Special emergency (Sondernotleistung), that is, 1.7 ata and above with B4 without MW injection. This is perfectly logical since the engine had to run in first and then set up for MW operation, including different throttle movements. Without MW your throttle gave 0,8-1,3 ata in the 0-100% movement range, and 1,42  ata at the 110% range, i.e. it was perfectly linear. With MW the setup was changed,  the first 0% - 100% of movement still controlled the throttle control the 0,8-1,3 ata boost region, but the last tiny 100% to 110% added almost the same boost, a whopping 0,4 ata boost to that on very little physical movement.

Thank you. that is what I have been saying to that argument for the G-14 MW50 manual.

And the manual (as it is for the AS Version) further allows to throttle up to 2800rpm at 8,5km height without MW-50 enabled (FTH for the DB605AS 9,0km at 2800rpm/1.42ata)  where the supercharger is no longer capable to provide enough boost to run the risk of overboosting if you push your throttle the last bit to 110%. and your boost will be in the range of 1.42ata.

So a further hint, that the late DB605 engine does not have a problem with 1.42ata

[Roland_HUNter]

On 12/30/2021 at 9:40 PM, VO101Kurfurst said:

 

 

This is not the first historical evidence about the 1.42 ata--> 3 min.
Still, why it's not implemented into the game?

[354thFG_Rails]

Because those are probably in conjunction with C3 fuel? In game are the 109's only running B4 fuel?

[JtD]

No, other references are from earlier days where C3 fuel was not being used or considered.

[Roland_HUNter]

http://www.virtualpilots.fi/feature/articles/109myths/#testflights

 

"Case: Me 109 G-6
For example 109 G-6 model's performance numbers are usually quoted from a flight test flown by mr. Brown. The actual plane was a 109 G-6/U2, which is a three cannon night fighter variant with night fighting equipment. Authors now take these numbers, drop away the information that it was a 3-cannon night fighter and voila, we got weak performance numbers for the G-6. The 3-cannon night fighter G-6 made 621 km/h in 30 minute power setting. A clean G-6 does 635-640 km/h with 30 min setting and 650+ km/h with 5 min WEP setting. So you can see that the wing cannons not only decreased speed, but they decreased the climb rate, roll rate and overall agility of the plane. "

[the_emperor]

Some more information on Speed perfomances for 1.3 and 1.42ata for the Bf-109 G-6 with Gondolas (3350kg) and G5/AS (3230kg) as well:

G-6 with Gondolas @ 1.3ata: ~502kph at 0m -> 620kph at 6600m FTH   /  

@ 1.42ata: ~520ph at 0m -> ~ 636kph at 6500m

 

 

 

Edited January 22, 2022 by the_emperor

[the_emperor]

From the Engine Card state Sept. 1942 issued Oct. 1942

 

From engine Card state Apr.44 issued June 44 (take-offand emergency power cleared. allowed for short runways and/or heavy planes and in emergency sitation in climb or level flight. Only limitation is the stressed and therefore wear of the engine):

 

one might conclude that that the main issue with earlier engines the limit to withstand higher rpms, which the revised engine could much more easily due to better oil lubrication system. Use of higher rpm and MAP was also counterd by a higher pressurised cooling system (25psi -> 28.4psi) with higher tolerances.

Still have not found any time limitation for the use take-off for the revised engine in effect of April ´44. This is also the time frame, where we have perfomance charts for the use of take-off and emergency power, but only for the G-5/G-6 models.

So take-off and emergency power should probably be blocked till April ´44 and cleared for use (currently unlimited (just in the logic of the game, not in reality) as I have not found manual that states otherwise yet) for late G-Models.

The Engine Card of ´44 says it supersedes the engine card of ´42, so the engine card of ´42 was in effect till then and take-off and emergency blocked. Thus far no manual with cleared Take-off/emergency power state 1 Minute use. Alls manuals with 1 Minute still state it blocked and are dated before April ´44.

[the_emperor]

Th 1944 pilots notes of the Fiat G.55 with the licensed built DB605A does not name any limits or bans of the emergency power setting, in fact is does not give any limits except for the water and oil temperatures and the rev limit of 2800 (+2%)rpm.

 

[the_emperor]

From D. (Luft) T. 2109 G-5 Teil 8D Sonderwaffenanlage

Heft 1: 21 cm BR (state of Mai 1944) Issue July 1944 p.10

 

Here we get a look at the tachometer of the Bf 109 G-5 (DB605A)

d (dauernd - continuous) -> 2300 rpm

30                                  -> 2600rpm

3                                    -> 2800rpm 

Edited June 15, 2022 by the_emperor

[the_emperor]

 Vorlaufige Flugstrecke He 177 A3 (DB 610 A/B) November 1943 p.6:

Edited June 15, 2022 by the_emperor

[Roland_HUNter]

It says after 10 minute usage, you had to use 5 minute in "lower engine performance".

"Die Sondernotleistung darf höchstens 10 minuten entnommen werden. bis zur nachsten entnahme ist eine pause mit gerginerer motorleistung von mindestens 5 minuten einzuschalten."

In the game now it is: 10 for 10 min.

[the_emperor]

29 minutes ago, Roland_HUNter said:

It says after 10 minute usage, you had to use 5 minute in "lower engine performance".

"Die Sondernotleistung darf höchstens 10 minuten entnommen werden. bis zur nachsten entnahme ist eine pause mit gerginerer motorleistung von mindestens 5 minuten einzuschalten."

This is for the use of „Sondernotleistung“ (1.7ata /2800rp. with MW50).

Up for discussion here is the usage of “Notleistung” (1.42ata/2800) without MW50 of the earlier DB605A engine.

But the “regeneration time” for WEP is certainly something worth investigating, probably for all planes.

 

[the_emperor]

Squadron Signal Publications 5543 Walk Around Messerschmitt BF109G Number 43

 

Aero Detail 5 Messerschmitt BF109G p.64

 

 

https://airandspace.si.edu/collection-objects/tachometer-german-fl-20286/nasm_A19600646000

 

I guess by now, we can sum up, that by late 1943 three minutes use of Start&Notleistung should be reasonable.

These pictures and sources (D. (Luft) T. 2109 G-5 Teil 8D Sonderwaffenanlage and the HE-177)  were already brought up by other forum members in 2018 , so Iam merely refreshing here what was already posted ~ four years ago.

So in addition with the run in procedures which state 5min WEP during run in of the engines (that would make the 3min even more reasonable to give the pilot  room of error/safety of 2min) 3min WEP should reasonable

Again, that all was in already posted in 2018! whooping 4 years ago...By now I really would like to see the engine Option for the G-4/6:

1) Start&Notleistung blocked

2) Start&Notleistung cleared (for 3min)

Edited December 19, 2022 by the_emperor

[the_emperor]

L.Dv.T.2109 G-5 und G-6/Wa Bedienvorschrift Wa (Schusswaffenanlage state of March 1943; issue April 1943) does also show a marking at 2800rpm, but unfortunately not very readable. But it sports the earlier 1942/1943 MAP gauge also displayed in the picture above of the Bundesarchiv with the 3 min marking at 2800rpm

 

 

Edited July 13, 2022 by the_emperor

[CUJO_1970]

Some of those G5 were also running C3 fuel I believe. 

[CountZero]

wonder what timer will 109G5 have in next DLC  

[Roland_HUNter]

De cockpit van een aan Zwitserland geleverde Bf 109G-6 in 1944

(Right click on the title near my picture and open it on new page, with the arrow on the right: not working)

 

 

After I reported it: at that time, they deleted the 3 min.
If you check it out nowadays.
For 1.42 the cell is empty.

 

[AndytotheD]

5 hours ago, CountZero said:

wonder what timer will 109G5 have in next DLC  

Hopefully I don’t take the thread too off track but would a G-5 have utility in low altitude settings and were they used for anything other Reich Defense?

 

There’s a lot of really cool research in this thread, I hope it sways the devs. 

Edited July 13, 2022 by AndytotheD

[the_emperor]

3 hours ago, AndytotheD said:

There’s a lot of really cool research in this thread, I hope it sways the devs. 

 

One just can hope so. All "my findings" are actually not from me, but I merely refreshed what was already brought forward in 2018  by other forum members and made it visible again. But thus far, there has been no reaction by the devs. One might have thought that correcting the engine timer  values  would be a minor thing, that could be changed along the road and would reward those who put in some work to correct (by backing it up with scources) what is incorrectly displayed in the game.

Edited July 13, 2022 by the_emperor

[Kurfurst]

'Bisher gesperrte Start- und Notleistung DB 605 kann nach Durchführung des Einfliegens von 10 Stunden entsprechend TAGTTIC 6., Nr. *, lfd. Nr. 705/43, entnommen ist jedoch nur in äussersten Notfällen und keinesfalls länger als drei Minuten zu entnehmen. Voraussetzung ist Vorhandensein des Überdruckventilles auf Schmierstofftank / Aenderung Bf 109G, Nr. 297. Drahtzug für Start- und Notleistung am Ladedruckregler ist einzuhängen und nötigenfalls Ladedruckregler auf 1,42 ata einzuregulieren. [...] Auf Ladedruck- und Drehzahlmesser sind für Notleistung die entsprechende Markierungen anzubringen. Zum Einstellen möglichts Spezialisten heranziehen. F.S. Gen. TT, Abt. G, vom 28.5.1943. betr. Start- und Notleistung DB 605 in Bf 109G is ausser Kraft gesetzt und zu vernichten.'

 

TMGL Nr. 44 07 019 vom 14.3.1944., S. 49.,

BArch RL 3/1293.

Via M. Baumgartl.

 

@Han, would you kindly take a look at this thread and fix this issue?

 

 

Edited July 22, 2022 by VO101Kurfurst

[the_emperor]

unfortunately I could not find it in a higher resolution  but the markings on the tachometer are visible:

[the_emperor]

So the 1min limit of Start&Notleistung seems to be applied to the DB603 /Me-410 as well

does any one have seen documents on that? thus far, I have online seen manuals without limit

[iFoxRomeo]

57 minutes ago, the_emperor said:

So the 1min limit of Start&Notleistung seems to be applied to the DB603 /Me-410 as well

does any one have seen documents on that? thus far, I have online seen manuals without limit

The Motorenkarte for DB603 from 03.1944 has no time limits for the powersettings

 

https://www.muzeumlotnictwa.pl/index.php/digitalizacja/katalog/838

[the_emperor]

Thank you @iFoxRomeo 

I only had the Motoren-Handbuch from 1942 and the Flugzeug-Handbuch from July 1943, and both dont state a limit but max temperatures and revs.

 

Edited September 1, 2022 by the_emperor

[FTC_DerSheriff]

 

Dont want to be a party pooper: While there is no rigit limit mentioned, they dont say there is "no limit"

 

Maximum Continous power suggests that the rest is limited.

Further more later in the doc under "Steig und Horinzontalflug"

Notleistung (Emergency Power) only in (surprise) emergencies.

 

Meaning that running these powersettings 24/7 is not what the manual implies quite on the contrary. However the rigit 1 min timer is ofc rubbish.

[CountZero]

Also i doubt there is any document stating that you have to wait 12-13min after using fully 1min alowed. How its in game after 1 min expire, 13 min after flying on combat or continuous you get full recharge of that 1 min. Probably longest expire to recover ratio in game for engines, for what reason its that long ? why its not 5min or 3min , why 12-13min. On K4 if you use 10min you recover 10min after flying 10 min on combat or continuous, why is 1:1 there but 1:13 here, makes no sence and i doubt any real world document or manual say you can use 1min emergancy only 1 time every 15min or so...

[the_emperor]

3 hours ago, FTC_DerSheriff said:

 

Meaning that running these powersettings 24/7 is not what the manual implies quite on the contrary. However the rigit 1 min timer is ofc rubbish

Absolutely. Als those limits are there to conserve the engine and keep its service life at the desired length. 
But an artificial 1min limit is weird. If you dont have limits on a power setting go with the limits on temperatures (they are in the manual). They did it with the Yaks/Laggs klimov M105PF engine. 
Reuse the wrong limit of a different plane/engine (DB605a) is simply wrong and quite frankly annoying. 

[the_emperor]

On 9/1/2022 at 2:57 PM, FTC_DerSheriff said:

 

Meaning that running these powersettings 24/7 is not what the manual implies quite on the contrary. However the rigit 1 min timer is ofc rubbish.

Hot Take:

Why not? why shouldnt we be able to run our engines at full power till my fuel tank (or MW50 tank) is empty (which might be faster than one might think)

and all engine parameters are in the green (temperatures of oil&water, oil pressure etc) and the engine is cleared for that power rating (so no over boosting/over revving).

that of course applies to all planes for all nations.

We dont have to care for service life of the engine. We use our planes for one flight and then discard it and get a brand new one, the next time we take off.

I know this is highly controversial but the premise of the game is, that we always get a brand new plane every time we take off.

I again would like again hint to the way CloD decided to go (in my view the bette one):

 

"Important to note, as has been mentioned, the historical pilot manual engine time limits were not a guaranteed point at which failure automatically occurred. 

 

But at the same time, as these aircraft were expected to have a service life longer than a single flight, it was important for pilots to be conservative whenever possible.

 

Basically the fact is, hard time limits are not an accurate way to model engine overheat.

 

The CLIFFS OF DOVER engine modeling physics system is the most complex of any simulation on the market.  There are no hard time limits on engine overheat and the potential damage effects of this situation.... There are a multitude of factors which affect how engines react to strenuous usage at full power and the game models most of those.

 

For example, if an aircraft is operating at high speed... thus with a high degree of efficiency in the cooling system due to the increased volume of air flowing through the radiator systems, it is much less likely to overheat when operating at full power.  Conversely, at slow speeds, with a much smaller volume of air passing through the radiator systems, engine cooling is less efficient and the likelyhood of overheat is much greater.  This factor tends to give an advantage to those pilots and types of aircraft which operate at high speeds and use 'Boom and Zoom' altitude based tactics... as the Jagdflieger tended to do in their Bf-109's.  Conversely, aircraft who tend towards tactics which emphasize 'turn and burn' tactics, i.e. slow speed turnfights, are penalized by the fact they are operating at low speeds, with reduced flow through their aircraft radiators.

 

Another example:  The density of the atmosphere has an effect on cooling efficiency... fewer molecules at higher altitudes means effectively less volume is passing through the radiator and therefore cooling is less efficient.

 

Third example:  As an aircraft approaches its engine's 'Full Throttle Height', i.e. the altitude at which the supercharger is working at maximum rate to impel air into the engine, that supercharger is generating more heat... and therefore the radiator systems are being challenged more heavily.  Combine this with the higher altitude, (less dense atmosphere) and an aircraft is more likely to overheat at altitudes closer to Full Throttle Height.

 

I could go on... there are a multitude of factors which are considered by the game's physics engine."

 

[PainGod85]

3 hours ago, the_emperor said:

Another example:  The density of the atmosphere has an effect on cooling efficiency... fewer molecules at higher altitudes means effectively less volume is passing through the radiator and therefore cooling is less efficient.

 

This is not supported by RL data. In fact, aero engines are at the highest risk of overheating while operating at low altitudes, where the air is the hottest.

 

Aerodynamics mandate that a certain mass of air has to flow across the wings to sustain level flight - this mass is inviolate regardless of altitude, but the higher you go, the colder the air gets, so it becomes more efficient at sinking heat. This means for a given airspeed (which also means a given maneuver reserve), the higher your altitude, the cooler your engine will run.

 

Decreases in maximum achievable airspeed are generally more than offset by the colder air at higher altitudes becoming much more efficient at sinking heat.

E: This also pertains to your third point, where air ingested into the turbo will obviously be colder at FTH than near the ground - while DB engines will indeed ramp up their rate of compression due to their fluid coupling and thus produce more heat at FTH than at SL, the air they're compressing will enter the impeller much colder, thus becoming a better heat sink.

 

Similar mechanics appy to geared superchargers, where the excess air below FTH is vented out of the system.

Edited September 3, 2022 by PainGod85

[JtD]

16 hours ago, PainGod85 said:

This is not supported by RL data. In fact, aero engines are at the highest risk of overheating while operating at low altitudes, where the air is the hottest.

 

Radials actually reach higher cylinder head temperatures at higher altitudes, because in their case the change in the air temperature is not sufficient to offset the change air density. Only with liquid cooled engines typical for WW2, this roughly cancels out.

 

20 hours ago, the_emperor said:

Why not? why shouldnt we be able to run our engines at full power till my fuel tank (or MW50 tank) is empty (which might be faster than one might think)

and all engine parameters are in the green

 

Because there's a ton of engine parameters you don't know about and which are still there, like oil viscosity, valve temperatures, exhaust temperatures, oil foaming condition, piston ring conditions, spark plug pollution and so on. There's a ton of components that is under extremely high stress when engine loads go up, and many of them can recover somewhat when the load goes down again or some special procedures are being employed.

Since it would be way too complex for a game like BoX to simulate each and every component that can break down on such an engine, some artifical restriction model needs to be in place. Personally I think this shouldn't be timers, but something needs to be there to make it somewhat realistic.

[the_emperor]

17 hours ago, JtD said:

Because there's a ton of engine parameters you don't know about and which are still there, like oil viscosity, valve temperatures, exhaust temperatures, oil foaming condition, piston ring conditions, spark plug pollution and so on. There's a ton of components that is under extremely high stress when engine loads go up, and many of them can recover somewhat when the load goes down again or some special procedures are being employed.

Since it would be way too complex for a game like BoX to simulate each and every component that can break down on such an engine, some artifical restriction model needs to be in place. Personally I think this shouldn't be timers, but something needs to be there to make it somewhat realistic.

I am with you on this.

but engine temperatures (water and oil) as oil viscosity can be monitored  and determine the state of the engine (as it was done via gauges). 

Just a thought:

the oil pressure could be used to show you whether your are in the green for WEP. if you are using it at some time it will start to drop and you have to watch, that it doesnt fall under the recommended specs, as then damage will occur. Then you would have to throttle back and see the oil pressure rise to nominal. 

You can further add, that every time  after using WEP the oil pressure does not rise to the starting pressure, so it drops a bit and  your intervals to use WEP become a bit shorter every time you tap into WEP to simulate engine wear.

I do think there is a way to simulate engine "nursing" in the game that is better than the timers.

and coming back to the topic of this thread:

 

I really hope that they correct the 1min for the DB605a with the up comming release of Normandy, as its been now over 4 years!

 

 

[the_emperor]

From He 177 A-3 Flugzeug Handbuch Teil 7 Triebwerksanlage (p. 13, August 1943):

 

Already mentioned but to be complete:

From Vorlaufige Flugstrecke He 177 A-3/R2 (November 1943, p. 5)

[the_emperor]

Well, as much as I am happy that we will get an 109/AS version, it will still sport the 1min limit for Start&Notleistung.

I guess that the time limit will not be corrected in the future, this is why I (I am sure not the first one to do this)  proposed an option to turn that mechanic off:

 

 

[Kurfurst]

No progress in fixing or investigating this in FIVE years…

[the_emperor]

I really dont know what the process is here to get that fixed or at least reviewed.

Thus far it has convincingly been shown that the DB605a should have either have the Start&Notleistung blocked or 3min limit. 
No document with 1min limit with unblocked Start&Notleistung has been produced yet

and with the upcoming AS version that error has been inherited. 
the 3min will be only able with c3 fuel though it should be 3min for B4/1.42 ata and C3/1.7ata alike.

[Roland_HUNter]

5 hours ago, the_emperor said:

I really dont know what the process is here to get that fixed or at least reviewed.

Thus far it has convincingly been shown that the DB605a should have either have the Start&Notleistung blocked or 3min limit. 
No document with 1min limit with unblocked Start&Notleistung has been produced yet

and with the upcoming AS version that error has been inherited. 
the 3min will be only able with c3 fuel though it should be 3min for B4/1.42 ata and C3/1.7ata alike.

Same on the Erla Haube 3d modell, In case you saw my thread about.

[the_emperor]

On 1/15/2023 at 2:34 PM, Roland_HUNter said:

Same on the Erla Haube 3d modell, In case you saw my thread about.

 

I did in deed. Should have been reviewed, too.

 

Though I guess that a simple value change from 1 to 3min for the Start&Notleistung should be easy doable since we dont have an complex engine simulation but a simple arcade time/boost/recharge mechanic.