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Performance of the DB605DB with 9-12159 propeller


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I cant really find anywhere a performance sheet for the DB605DB with 9-12159 propeller which is modeled in DCS.

Ive only found the sheet for the DB605DB with 9-12199 prop performance:

- WEP (Sondernotleistung) (1,8 ata with MW50) - 600 km/h at SL, 725 km/h (max) at 7000m

- Climb/combat power (Steig- Kampfleistung) (1,45 ata) - 540 km/h at SL, 700 (max) at 8000m (675 km/h at 7000m)

-(Takeoff setting???) Start - Notleistung (1.5 ata) - 550 km/h at SL, 700 (max) at 8000m (675 km/h at 7000m)

5026-27_DBSonder_MW_geschw.jpg

 

 

There is 9-12159 line there but only for Sondernotleistung: G=3400kg

- 595 km/h at SL, 710 km/h at 7000m

But as I tested it in game at 7000m it only goes to about 685 km/h

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At lower powers the speed difference should be roughly the same as at Sondernotleistung, ie. ca 10 km/h. The climb was the same with both props.

 

In January 1945 they tested a K-4 with 4 different props, all at 1,35ata (so less than the DB/DC 30-min rating), the difference wasn't breathtaking, but noticable: 3-4 km/h at lower altitudes, and ca 10 km/h at VDH, between the ...159 and ...199 props.

http://www.kurfurst.org - The Messerschmitt Bf 109 Performance Resource Site

 

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The Answer to the Ultimate Question of the K-4, the Universe, and Everything: Powerloading 550 HP / ton, 1593 having been made up to 31th March 1945, 314 K-4s were being operated in frontline service on 31 January 1945.

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At lower powers the speed difference should be roughly the same as at Sondernotleistung, ie. ca 10 km/h. The climb was the same with both props.

 

In January 1945 they tested a K-4 with 4 different props, all at 1,35ata (so less than the DB/DC 30-min rating), the difference wasn't breathtaking, but noticable: 3-4 km/h at lower altitudes, and ca 10 km/h at VDH, between the ...159 and ...199 props.

 

Regarding the fact that the planes of batch production had greater differencies in the max speed, 3 and 10 kph difference has only academic science significance.... :)

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Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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Regarding the fact that the planes of batch production had greater differencies in the max speed, 3 and 10 kph difference has only academic science significance.... :)

 

So how big is the difference then?

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So how big is the difference then?

 

Basically the numbers you on the chart above is the "nominal" speeds the aircraft, a sort of generic avarage, which the aircraft manufacturer guaranteed within certain range, typically within +/- 3%.

 

When an aircraft was produced, it was put through short acceptance tests of a couple of minutes duration - those that did not meet the +/- 3% criteria were rejected and the manufacturer had to fix them up.

 

For the 109K this means the manufactured planes had to achieve anywhere between ca. 690 and 730 km/h to be accepted for service. So, I agree with YoYo, the difference so small that that its mostly academic, as in real life there were large variations between individual planes... same goes for which plane was faster argument, when their "official" figures are just a few ten kilometer per hour away... ;)

http://www.kurfurst.org - The Messerschmitt Bf 109 Performance Resource Site

 

Vezérünk a bátorság, Kísérőnk a szerencse!

-Motto of the RHAF 101st 'Puma' Home Air Defense Fighter Regiment

The Answer to the Ultimate Question of the K-4, the Universe, and Everything: Powerloading 550 HP / ton, 1593 having been made up to 31th March 1945, 314 K-4s were being operated in frontline service on 31 January 1945.

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  • 4 weeks later...
I cant really find anywhere a performance sheet for the DB605DB with 9-12159 propeller which is modeled in DCS.

Ive only found the sheet for the DB605DB with 9-12199 prop performance:

- WEP (Sondernotleistung) (1,8 ata with MW50) - 600 km/h at SL, 725 km/h (max) at 7000m

- Climb/combat power (Steig- Kampfleistung) (1,45 ata) - 540 km/h at SL, 700 (max) at 8000m (675 km/h at 7000m)

-(Takeoff setting???) Start - Notleistung (1.5 ata) - 550 km/h at SL, 700 (max) at 8000m (675 km/h at 7000m)

5026-27_DBSonder_MW_geschw.jpg

 

 

There is 9-12159 line there but only for Sondernotleistung: G=3400kg

- 595 km/h at SL, 710 km/h at 7000m

But as I tested it in game at 7000m it only goes to about 685 km/h

 

Don't quote me, but I've researched the props at one point.

 

The 199 is the better prop that was used on the K4. The 159 is the initial prop that started with the K4 and later was converted to the 199 prop.

 

It's a little disheartening for me, that the K4 is using the DB config rather than the DC config which has a wider and higher range of power than the DB with the inclusive 199 prop.

 

The only difference between the DB and DC engine performance patterns that I saw was at lower altitudes; The DC produced more power, but above 6000m they were nearly identical in power.


Edited by Page.Down
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It's a little disheartening for me, that the K4 is using the DB config rather than the DC config which has a wider and higher range of power than the DB with the inclusive 199 prop.

 

Why disheartening? It isn't as though our K4 has a competitive disadvantage compared to our P-51D. The 109 is currently faster, better climbing, & better turning than the P-51, at normal altitudes. As such, it dominates in dogfights. Why would you want to exacerbate that disparity?

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Why disheartening? It isn't as though our K4 has a competitive disadvantage compared to our P-51D. The 109 is currently faster, better climbing, & better turning than the P-51, at normal altitudes. As such, it dominates in dogfights. Why would you want to exacerbate that disparity?

 

As tested by DavidRed and other talented pilots.The p51 turns better than the 109.Less talented pilots have a different opinion.

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Sorry, Otto, I don't buy that. At normal multiplayer altitudes, the 109 turns better in all but the most unusual of circumstances. (As it should, I might add; the real 109 did out-turn the P-51, in general.)

 

Are you doing that thing where someone say something that's technically true, but omitting critical information that alters the meaning completely? You know, the thing that advertisers like to do. "NUMBER ONE RECOMMENDED BRAND BY DOCTORS" (... all two of the doctors they consulted)

 

In this case, it'd be "the P-51 turns better than the 109" (at very high altitudes, or when it has a massive E advantage to burn up on high-speed turns). Not an honest way of describing the comparison, when you leave off that game-changing aftertext.

 

So, a more accurate statement would be: the 109 out-turns the P-51 in almost all co-X situations in multiplayer. (Insert a number of things for X ... E, numbers, fuel loads, pilot experience levels, etc.) That's in addition to climbing better (as it should) and being faster (which isn't right, because the P-51 has an acknowledged bug causing massive losses in its top speed at normal altitudes).

 

Which brings me back to my original question: if the current 109 already tends to dominate the P-51, in co-X situations, then why in the heck should anyone be crying about one of the more down-to-earth engine/propeller/Ata being used, rather the most extreme high-performance variants?

 

You can't have your cake and eat it, too, especially when it's already skewed in your favor. If you're going to make the argument that the 109K should be using the best propeller/engine/Ata it ever used, then we'd have to take a good hard look at the P-51D, which is using the worst of the WEP settings P-51Ds were rated for. Not "slightly less than the best," but the very worst! You can't complain about having a slightly less-than-optimal performance 109K when we've got a very sub-standard P-51D, and the former dominates the latter as a result. ("Sub-standard" meaning a configuration which is less than the contemporary standard at the point in the war where the two would have met--not implying an actual error in data or modelling.) And all of that applies even if the P-51 didn't have that bug with its speed--that's just icing on the cake, and the problem of standards will remain after the bug is fixed.


Edited by Echo38
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The p51 turns better than the 109.

 

This is true.

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This is true.

What altitude, what speed range and what load. It all matters. You can't just say plane A turns better than plane B. In some cases differences are more pronouced... but not in case of Me109K4 vs P-51D

 

For both planes with standard loads:

At high speed IAS (550-750+ kph) at low alt 0-3000m, P-51D is going to turn better than 109 simply because the 109 pilot won't have enough strenght to pull. At around 300-450kph the difference between those planes will probably be impossible to track. Both pilots would probably be able to turn simillarly. At speed bellow 300kph, the 109 is going to have an advantage in a sustained turn and pushing the nose into vertical will create a situation where the P-51 pilot will be unable to follow (beeing heavier and having less power).

 

 

At high altitude(7000-9000m) it would also be close, but P-51 should be able to outturn the 109.

*Disclaimer! All numbers are rough estimates based on my personal experience with DCS and other simulations and many read books and articles.


Edited by Solty

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What Solty said. At normal multiplayer altitudes, sustained turning ability matters more than instantaneous turn, in general, because the fight drops down to sustained speeds quickly. You can't keep up a high-speed fight for long unless you've got loads of altitude to burn.

 

More importantly, a fighter that only turns better at high speed needs to start out with an altitude advantage over his opponent, because these high-speed turns bleed too much energy to do it in a normal situation; in a standard duel merge, by the time the P-51 has "gotten behind" his opponent, his opponent is now too high above him to reach before stalling. And now the opponent can do a nice sustained turn overhead, out-turn on a higher plane, then roll over for the attack. "Out-turn him at high speed" is something that people always recommend to pilots of lesser-turning aircraft like the P-51, but it only works in situations that are unusual in a co-X fight.

 

So, again, my objection: "The P-51 turns better than the 109" is technically true, as part of a larger statement ("the P-51 turns better than the 109 under specific conditions"), but the implied meaning from leaving the statement unfinished like that is dishonest, because the implication is that the P-51 usually or always turns better than the 109, which is false more often than it is true (in normal multiplayer battles, which tend to occur somewhere around ten thousand feet).

 

In the end, what I see is players with a 109 that's performing better than the P-51 (because the P-51 is underperforming for several reasons), expressing disappointment that the 109 isn't doing even better, and then pretending that the P-51 has the advantage (when it usually has the disadvantage, under these conditions). I can't see it as anything else but intellectual dishonesty & poor sportsmanship.


Edited by Echo38
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What altitude, what speed range and what load. It all matters. You can't just say plane A turns better than plane B. In some cases differences are more pronouced... but not in case of Me109K4 vs P-51D

 

For both planes with standard loads:

At high speed IAS (550-750+ kph) at low alt 0-3000m, P-51D is going to turn better than 109 simply because the 109 pilot won't have enough strenght to pull.

 

Even if we assume that the 109 pilot can't pull as much Gs at high speed as the P-51 pilot, it will be only true for instantenous turn rate since the "g-pull limit" advantage will be in speed regions which cannot be sustained on any prop job during manouvering. So its at best a very brief turn advantage before the speed bleeds down quickly.

 

At high speeds sustained turn is so limited because of repidly increasing drag that any sustained turn will be marginal and unsuited for any combat manouver.

 

The only possibility of having better high speed sustained turn is either lower parasitic drag and/or higher thrust - and the 51 certainly will not have higher thrust, since its engine is weaker, at all altitudes.

 

Which leaves parasitic drag, where the 51 may have a very slight advantage or parity, the question is, whether it is enough to not only offset, but exceed the thrust advantage of the 109K... given the great similarity in top speeds, its may be just enough at lower altitudes for parity, but certainly not for greater excess thrust, especially not at altitude.

 

At around 300-450kph the difference between those planes will probably be impossible to track. Both pilots would probably be able to turn simillarly. At speed bellow 300kph, the 109 is going to have an advantage in a sustained turn and pushing the nose into vertical will create a situation where the P-51 pilot will be unable to follow (beeing heavier and having less power).

 

Again, roughly the same physics apply and same power and drag characteristics are possessed at any but extreme high speeds near Vne, except that parasitic drag becomes less and less important, which is why the 109 turn advantage increases.

 

At high altitude(7000-9000m) it would also be close, but P-51 should be able to outturn the 109.

 

Why? Aspect ratio, overall drag in turns (=less drag) high altititude propeller efficeny and engine output (=more thrust)...? High altitude is essentially analogous low speed turning environment.

 

*Disclaimer! All numbers are rough estimates based on my personal experience with DCS and other simulations and many read books and articles.

http://www.kurfurst.org - The Messerschmitt Bf 109 Performance Resource Site

 

Vezérünk a bátorság, Kísérőnk a szerencse!

-Motto of the RHAF 101st 'Puma' Home Air Defense Fighter Regiment

The Answer to the Ultimate Question of the K-4, the Universe, and Everything: Powerloading 550 HP / ton, 1593 having been made up to 31th March 1945, 314 K-4s were being operated in frontline service on 31 January 1945.

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Wait, what? At least at normal altitudes, the Thunderbolt didn't come close to out-turning 109s in sustained turns. In the two or three wartime graphs I've seen of sustained turning circle comparisons, the Thunderbolt was way behind the 109 & P-38 et al, and considerably behind the P-51 as well (which, in turn, was behind the P-38 & Me 109). The only major fighter that the P-47 could flat turn with, for more than brief times, was the FW 190.

 

At extremely high altitudes, where the P-47 was really at home, that might change; perhaps there, the Thunderbolt could out-turn the 109. But we don't usually fight at angels 30 & 40 in multiplayer.

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  • 4 years later...
As tested by DavidRed and other talented pilots.The p51 turns better than the 109.Less talented pilots have a different opinion.

 

I think you wanted to say "P-51 has much more manageable stick forces then bf 109".

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  • 1 month later...

DB 605D power chart. Lower max. rating is for the DB / 1,80 ata setting we have in DCS.

1741017086_DB605Dpowercurves.thumb.jpg.78d985421571c9a85b5ca26c1f589d46.jpg

http://www.kurfurst.org - The Messerschmitt Bf 109 Performance Resource Site

 

Vezérünk a bátorság, Kísérőnk a szerencse!

-Motto of the RHAF 101st 'Puma' Home Air Defense Fighter Regiment

The Answer to the Ultimate Question of the K-4, the Universe, and Everything: Powerloading 550 HP / ton, 1593 having been made up to 31th March 1945, 314 K-4s were being operated in frontline service on 31 January 1945.

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GM1 gives nice boost :)

1600hp at 20k ft that's a lot

 

Indeed, especially on the earlier 605As GM1 injection was very brutal for the time, and came in on more common altitudes.

 

Also there is good power indeed (its a big supercharger), the most impressive thing about IMO that it comes all altitudes. No zigzag power drops like on Merlins and BMWs, due to variable speed hydraulic coupling on the charger drive.

http://www.kurfurst.org - The Messerschmitt Bf 109 Performance Resource Site

 

Vezérünk a bátorság, Kísérőnk a szerencse!

-Motto of the RHAF 101st 'Puma' Home Air Defense Fighter Regiment

The Answer to the Ultimate Question of the K-4, the Universe, and Everything: Powerloading 550 HP / ton, 1593 having been made up to 31th March 1945, 314 K-4s were being operated in frontline service on 31 January 1945.

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Indeed, especially on the earlier 605As GM1 injection was very brutal for the time, and came in on more common altitudes.

 

Also there is good power indeed (its a big supercharger), the most impressive thing about IMO that it comes all altitudes. No zigzag power drops like on Merlins and BMWs, due to variable speed hydraulic coupling on the charger drive.

 

Ther is small zigzag at low alt because Variable speed supercharger kicks in from certain alt, solution is just amazing, in 45 it wasn't very impressive anymore, where allies were using very good charging systems with inter cooling, but at beginning of the war this solution was throwing competition on the knees :)

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  • 1 month later...
As tested by DavidRed and other talented pilots.The p51 turns better than the 109.Less talented pilots have a different opinion.

 

Where is this info, and how? I have done turn rate tests with the 109K4 and P51D at sea level with different fuel loads and the 109K4 wins easy.

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