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E69_geramos109

MW50 weird behavior

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53 minutes ago, L3Pl4K said:

Cheap superchargers from china..maybe. Hope we will see genuine parts in the next update.

Yes, cheap and „will ship to Nazi Germany“.

Edited by ZachariasX

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9 hours ago, JtD said:

OK, since I have trust issues when it comes to testing I climbed the G-14 myself. On the Lapino autumn map, from sea level to 5.5km. I had the rads on manuals 50%. In the test I linked above, they were at "Steigflugstellung" (climb position), whatever that is in game terms. I didn't want to have to deal with automatic adjustments and the related effects, so I put them on manual.

 

 

If you retry the test with auto rads does it better match the data? maybe the devs coded it with auto rads in mind, or maybe the rads have too much drag? When climbing in a G-6 at 1.42 ata the max they open is 30-31% in automatic mode. Are you sure the test setting was 50%?

Edited by -=PHX=-SuperEtendard

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On 7/27/2018 at 3:03 PM, III/JG52_Otto_-I- said:

The three conjugated system who regulated the inlet manifold pressure of the DB-601 and DB-605 engines series were the same for all.
The manifold pressure still the same from sea level to the compressor ceiling altitude. 
The ram air pressure, do not affect to manifold pressure until the compressor ceiling (rated altitude), because ram air was taken prior to the compressor. 
The compressor speed is regulated in accordance with manifold pressure. If the ram air pressure increase the manifold pressure, the boost control, and the compressor speed control, will reduce the compressor speed for compensating the final manifold pressure.
A.T.A means "Absolute Atmospheres", it is not in reference to exterior pressure of the system.

The exaggerated ram air influence in manifold pressure of the G-14 in game, is clearly a big bug.

Db-601&DB-605 engines_power_control.jpg

im not saying there isnt a bug, just that a non-AS model cant hold 1.7 ata to 6.8km. More like 4.5

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8 hours ago, -=PHX=-SuperEtendard said:

If you retry the test with auto rads does it better match the data? maybe the devs coded it with auto rads in mind, or maybe the rads have too much drag? When climbing in a G-6 at 1.42 ata the max they open is 30-31% in automatic mode. Are you sure the test setting was 50%?

 

I don't think they will match better, because the difference between climb speed down low and at 4 km altitude is too high. With auto, the only effect could be that the cooling flaps are closed down low and open up a bit as I climb, and this would make the match worse. Like I said, real life test was done with Steigflugstellung (climb position), and I don't know what that is in detail. I doubt it was automatic, because typically they said that if that's so. Typically it is some middle setting and I went with 50% in game, because it's my best guess.

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2 hours ago, JtD said:

 

I don't think they will match better, because the difference between climb speed down low and at 4 km altitude is too high. With auto, the only effect could be that the cooling flaps are closed down low and open up a bit as I climb, and this would make the match worse. Like I said, real life test was done with Steigflugstellung (climb position), and I don't know what that is in detail. I doubt it was automatic, because typically they said that if that's so. Typically it is some middle setting and I went with 50% in game, because it's my best guess.

 

http://kurfurst.org/Performance_tests/109G_MT215/109G2_MT215_en.html

 

"German calculations typically assume a standard radiator flap position, referred to as Steigflugstellung (or climbing position), at which the radiator`s exit flaps(Kühlerklappen) are open 220 mm wide, or apprx. half-open, and 74mm at the variable the inlet (Einlaufflippen), in order to provide imcreased airflow during the slow-speed climbs."

 

Kuhlerklappen.jpg

 

"The actual flight trials performed by Messerschmitt A.G. only vaguely follow such theoretical considerations; the position of the radiator flaps - and thus the measured performance - greatly varies between as little as 130-150mm  and wide-open as 350mm."

 

E: Also, I agree, the results for the ingame G-14 are so grievously out of bounds with how the plane is supposed to perform it cannot be explained by something as little as partially open radiators.

 

E2: So many broken links @VO101Kurfurst

Edited by PainGod85
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I knew the info was around somewhere, thank you for bringing it here. So the 50% guess was about right, though 60% might have been more accurate.

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Anyways, @VmaxIL2 and I ran some pressure calculations.

 

The DB 605A's supercharger has a pressure ratio of around 2.9, calculated from the critical altitude for 1.42 ATA and the air pressure at the same (5700 m, 0.49 atm).

 

This means for 1.7 ATA, given the standard atmosphere model, FTH would be just shy of 4280 m (0.5866 atm), which corresponds well with German test results.

 

[edited]

 

2. This forum is provided by 1C-777 Ltd. as a courtesy and its usage is a privilege and 1C-777 Ltd. reserves the right to ban any member temporarily or permanently for any reason at any time. Any penalties listed below for violations of the rules are guidelines only and forum administration may take additional action if they feel it is warranted. Use of the forum is not connected to usage of the game and access to this forum is not guaranteed to users as a consequence of purchasing the game.
 

 

Link to the calculator I used: https://www.mide.com/pages/air-pressure-at-altitude-calculator

Edited by SYN_Haashashin

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14 minutes ago, PainGod85 said:

I am very confused how a team of professional engineers did not run this very simple set of calculations to fact check their model

 

Well, it is still in Beta after all...

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9 minutes ago, =EXPEND=SchwarzeDreizehn said:

 

Well, it is still in Beta after all...

 

A radiator not working as it should is an issue I expect in a beta. Some functionality to not be implemented yet I expect in a beta. Some content missing is something I expect in a beta.

 

Getting basic physics wrong in such a way I needed less than five minutes to conclusively prove it is not something I expect in a beta.

Edited by PainGod85

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That's not the point anyway.

 

The point is the team apparently misunderstood the workings of the DB605A supercharger (maximum boost provided should not be depending on ram effects, only FTH should) and forgot to adjust it to the higher boost (supercharger setup change). I've prepared a little illustration to get the point across a little bit better.

 

Dark blue line: Taken from DB605 manual - this is the pressure the DB605A supercharger provides at 2800rpm, for standard operation. It's got an odd shape, because of the hydraulic coupling. After the supercharger does its job, the pressure is regulated so that the cylinders only work at 1.42ata (red line).

Because at increased boost 1.7ata the supercharger was re-set to engage the second gear/hydraulic coupling already at 600m, it would run at higher rpm at the same altitude, thus providing higher boost. That's the yellow line. It again was regulated so that only 1.7ata reached the cylinders (green line).

What we see in game is - nothing. The supercharger still appears to provide the standard 1.5some ata, as if it was not reset. Also, boost drops constantly up to about 2000m That's wrong.

 

To counter this problem, it appears the devs have programmed an odd ram effect, that does not increase full throttle altitude as it should (yellow line, brown arrow, dark brown line). Instead, the ram effect appear to increase boost throughout the altitude range (dark blue line, blue arrow, light blue line).

Technically the dev version could be true, if the supercharger clutch worked on static environmental pressure, but it takes ram air from the supercharger intake instead. So that's wrong, too.

 

Hope it helps.

 

bla010.thumb.jpg.558375546fef13e8b3c31ac9333a9372.jpg

Edited by JtD
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The main question is, do the indicated ATA on the dial actually show accurate values?

 

Flight test on climb and performance are less than conclusive, so is it graphical or performance? 

Because this is computer game, there can be disconnect of the stuff that goes under the hood and the values shown on the pegs and dials. 

 

It can show over 9000 ATA and the plane can preform nominally according the specs anyhow. 

Edited by Cpt_Siddy

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HP and speeds are provided as separate entities from various other documentations and they need to match these numbers, not the ata. So; i guess there is a correlation, but as JtD pointed out, they chose a workaround to get them to match. I do think it will have an impact on places on the curve that they could not directly match from other data, but that they had to interpolate.

Edited by =EXPEND=SchwarzeDreizehn

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4 hours ago, JtD said:

supercharger was re-set to engage the second gear/hydraulic clutch

The supercharger coupling of the DB-60x series, have not "second gear" because it have a Föttinger hydraulic coupling, who provide a infinite mechanical relations, in other words infinite gears.

Maximum spin relation between the crankshaft and the compressor impeller is about  1:10

Spoiler

 

 

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1 hour ago, III/JG52_Otto_-I- said:

The supercharger coupling of the DB-60x series, have not "second gear" because it have a Föttinger hydraulic coupling, who provide a infinite mechanical relations, in other words infinite gears.

Maximum spin relation between the crankshaft and the compressor impeller is about  1:10

  Hide contents

 

 

 

Not quite correct. The DB 60X has two different modes of SC operation.

 

The first is a fixed mechanic coupling for low altitudes up to 2 km at 1.42 ATA.

 

The second is your hydraulic coupling providing infinite gears.

 

So in essence, it dies have two gears, it's just that they don't use the same principle of operation.

Edited by PainGod85

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31 minutes ago, PainGod85 said:

 

Not quite correct. The DB 60X has two different modes of SC operation.

 

The first is a fixed mechanic coupling for low altitudes up to 2 km at 1.42 ATA.

 

The second is your hydraulic coupling providing infinite gears.

 

So in essence, it dies have two gears, it's just that they don't use the same principle of operation.

You're wrong. The DB-600 had only a mechanical one gear compressor, and carburettor. DB-601series onwards had hydraulic Föttinger coupling. there aren't second gear. it select the apropiate spinnig speed from zero (no oil inside ) to 10:1 (full of oil).

 

Screenshot_20180729-195351.png

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17 minutes ago, III/JG52_Otto_-I- said:

You're wrong. The DB-600 had only a mechanical one gear compressor, and carburettor. DB-601series onwards had hydraulic Föttinger coupling. there aren't second gear. it select the apropiate spinnig speed from zero (no oil inside ) to 10:1 (full of oil).

 

Screenshot_20180729-195351.png

 

Right, it's not actually a mechanical coupling, just two modes of delivering the oil. One delivers at a fixed ratio, the other varies according to selected MAP and inlet pressure. My bad for getting it wrong.

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17 hours ago, PainGod85 said:

 

Yes, on a D. Not an AM.

Yes, ..but 1,98 ATA Is NOT "nice fantasy" for a DB-605  :P

Edited by III/JG52_Otto_-I-

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They could run the engine settings on a little bit leaner mixture and get a bit more range out of the aircraft. What about it?

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42 minutes ago, E69_geramos109 said:

Wow imagine if germans had that 100-130 octane fuel for the dbs.

 

 

If the DB-605 ran same compression rations as inter cooled Merlin on p-51, they would need to make changes in many places, like bigger prop with more blades to take advantage of the extra power. 

 

bhp don't translate to more performance directly. And engine with larger displacement comes its own problems. 

Edited by Cpt_Siddy

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8 hours ago, III/JG52_Otto_-I- said:

Yes, ..but 1,98 ATA Is NOT "nice fantasy" for a DB-605  :P

 

I never said it wasn't a nonexistent engine rating. I'm saying the DB 605 A could not sustain more than 1.7 ATA in any of its configurations.

 

And I'm somewhat doubtful the 1.98 ATA rating on the DC ever got beyond a few engines for testing purposes.

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14 hours ago, E69_geramos109 said:

Wow imagine if germans had that 100-130 octane fuel for the dbs.

 

They had that already in 1940. All the early 109Fs were running on it for example.

But why put up with just 100/130 grade fuel when you already have 150 grade fuel a years before the Allies? ;)

 

C3-150grade.png.b78aa0303c949063fadc32b0673f011f.png

 

9 hours ago, PainGod85 said:

 

I never said it wasn't a nonexistent engine rating. I'm saying the DB 605 A could not sustain more than 1.7 ATA in any of its configurations.

 

ASB - 1.8 ATA, ASC - 1.98 ATA

 

Though these were probably hybrids of 605 A and D series.

 

9 hours ago, PainGod85 said:

And I'm somewhat doubtful the 1.98 ATA rating on the DC ever got beyond a few engines for testing purposes.

 

That's OK but essentially its a baseless statement.

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13 hours ago, PainGod85 said:

And I'm somewhat doubtful the 1.98 ATA rating on the DC ever got beyond a few engines for testing purposes. 

 

That boost was operationally tested but not officially cleared for use til late March 1945. There has been no proof ever provided that the 4 Gruppes cleared for its use ever did so, only fantasy speculation that it was.

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Who cares? This topic is about the wrong 1.5ish ata MW50 system on the Bf109G-14 as we have it in game.

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Someone having an opinion different from yours isn't history revisionism. It's opinion.

 

Anyway, it would be nice to let this topic deal with the MW50 injection as it is in game, just in case something new comes up.

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10 minutes ago, JtD said:

Someone having an opinion different from yours isn't history revisionism. It's opinion.

 

Anyway, it would be nice to let this topic deal with the MW50 injection as it is in game, just in case something new comes up.

 

Yes, and before the K-4 get's released - it would be really sad to see it down-rated....

 

( Hey, see?, I'm ( ---> ME <--- ) actually talking ww2 engine stuff !!! not knowing the slightest about it.... )

Edited by Von-Target

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2 hours ago, MiloMorai said:

 

That boost was operationally tested but not officially cleared for use til late March 1945. There has been no proof ever provided that the 4 Gruppes cleared for its use ever did so, only fantasy speculation that it was.

 

So basically a few engines for testing purposes. :P

 

That said, I think there's been enough material posted here regarding the G-14's faulty engine implementation that we can now report it as a bug, right?

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Thank you gents for your time and efforts too bring this to light . It's much appreciated . Let's hope the next update brings good news.   

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On ‎8‎/‎1‎/‎2018 at 3:32 AM, VO101Kurfurst said:

 

They had that already in 1940. All the early 109Fs were running on it for example.

But why put up with just 100/130 grade fuel when you already have 150 grade fuel a years before the Allies? ;)

 

C3-150grade.png.b78aa0303c949063fadc32b0673f011f.png

 

 

That is either a typing error OR the document, of unknown source, has been doctored.

 

Mid war C3 fuel was ~125PN. Late war C3 was ~140PN but no proof that it was issued to operational units.

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On 7/24/2018 at 4:17 PM, E69_geramos109 said:

Lets see if someone knows if that is correct or not. For me dynamic supercharger effect seems overmodelled.  

 

One important note from me to your test -> Like you did in 3:33 this time you increase the rpm to 3000 and you will see 1,58 ata instead of 1.42 ata how you shown in your  video.

+200 rpm result into +0.5 ata more with MW-50. MW-50 need pressure to work correct and how you create pressure with speed or in climb with more rpm.

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Is the speed of Bf-109G14 too high?

 

@Gavrick, from that topic:

 

Quote

 

The maximum speed is indicated for the Bf-109 G-14 aircraft, with the DB-605AM motor, with the MW-50 system turned on, without hanging cannons (and, even more so, tanks).

What we have:

The graph, in which the speed Bf-109 G-14 with outboard guns and with the MW-30 system - 568 km / h off the ground.

There is a table in which it is said that such a speed reached a plane with a weight of 3300, that is, without suspensions.

There is a table in which it is indicated that the speed of the Bf-109 G-14 with the suspension cannons and the MW-50 system at the ground is 557 km / h.

At the same time, we take into account that the composition of the MW-30 mixture was slightly different from the MW-50, with the use of which the power increase was slightly higher, probably.

Total.

The speed at the ground, using MW-50 and with suspensions according to documents - 557 km / h, in the simulator - 562 km / h (in ideal conditions, and). The difference is 5 km / h, less than a percentage.

The speed near the ground, using the MW-30 and, probably, without hanging under the documents - 568 km / h, in the simulator with MW-50 and without hangers-576 km / h (again, under ideal conditions). The difference is 8 km / h, the percentage with kopecks.

So what's the problem?

 

Edited by LukeFF
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Problem can be climb performance, acceleration from low speeds etc. Not just top speed measured on the deck where mw50 seems to work ok. 

If that is not affecting performance on the game could be just the animation.

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I'd like to add that G14 cannot hold it's 1.7 ATA with MW50 enabled above 2km, where it fluctuates between ~1.5 and ~1.7, depending on speed.

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