BF109K FM- Propeller Type

[shift8]

Based on the speeds the BF109K gets in Aces, it appears to be modeled with the experimental Dunblatt Propeller that was never fitted to production planes in real life. Use of this prop is where the 454mph figure comes from, which incidentally is how fast the in game K goes at critical alt. In given that HT requires a plane to have seen combat to be in game, it seems odd to me that the 109 would be modeled in such a fashion. 109K's would be able to do about 441 at crit, and 360 without the prop. Curious if anyone know what this is all about, and If it is an error if we could get it changed.

[Karnak]

Do you have more information on this?  Primary source documents?

[shift8]

Documentation can be found here: http://www.spitfireperformance.com/spit14v109.html

an Excerpt:

"The Projektbüro estimate from 19.1.45 assumes 9-12159 propeller, and a weight of 7,496 lbs. Documentation listed below demonstrates that newly delivered Me 109 K-4's were equipped with a DB 605 DB engine operating with 1.80 ata/2800 rpm engine limitations beginning approximately mid January 1945. Various engine and propeller configurations were experimented with. The 9-12159 propeller was the standard production propeller but various German curves are extant showing estimated performance of the Me 109 K-4 with 9-12199.10 and 9-17018.10 thin blade (Dünnblatt) props and Projektschraube with 4 light-metal blades. The 452 mph figure often cited as the top speed of the Me 109 K-4 derives from an estimate assumming an experimental 9-12199 Dünnblatt propeller. The DB 605 DC engine running at 1.8 ata boost without MW-50 was tried but did not find favour. (Die E-stelle hat Bedenken gegen den Betrieb mit 1,8 ata Aufladung ohne MW mit C 3 Kraftstoff.) The DB 605 DC engine running at 1.98 ata boost with MW was tested but seems not to have made it into service (Nach Mitteilung der E'Stelle sind 1,98 ata gesperrt.)"


http://imgur.com/bgvClo1

[EagleDNY]

I prefer my 109 info from Kurfurst, as he seems to have done much more research on the various 109 types and subtypes than the guy over at spitfireperformance.

http://www.kurfurst.org/Engine/Boostclearances/605D_clearance198.html

All I can say is that I don't find that our 109s are overmodeled given the data over there.   If anything it seems like we have one of the lesser G-14 engines and we could really use the update to a better one.

[GScholz]

[shift8]

I prefer my 109 info from Kurfurst, as he seems to have done much more research on the various 109 types and subtypes than the guy over at spitfireperformance.

http://www.kurfurst.org/Engine/Boostclearances/605D_clearance198.html

All I can say is that I don't find that our 109s are overmodeled given the data over there.   If anything it seems like we have one of the lesser G-14 engines and we could really use the update to a better one.

Regarding the dunnblatt propellor, even Kurfurst himself admits that it was never used.

"Altough it is believed the so-called Dünnblattschraube VDM 9-12199 was not standardized, this report is of special interest it also shows - as a reference - the performance of the serial production Bf 109K-4 with standard VDM 9-12159 propeller and as such it is a valuable resource for the basic performance figures of this last, potent subtype, at it`s numerous combinations of the engines, manifold pressures and MW-50 boost used."----Kurfursts site.

Also as per Mr. Kurfurst:

http://kurfurst.org/Performance_tests/109K_PBLeistungen/files/5026-27_DBSonder_MW_geschw.jpg

The correct curve for the production prop is the thin line: the second fastest, showing 442mph.

[bozon]

(Image removed from quote.)

He pours the drink but the glass never fills!
What foul magic is that?!
 

[MiloMorai]

I prefer my 109 info from Kurfurst, as he seems to have done much more research on the various 109 types and subtypes than the guy over at spitfireperformance.

http://www.kurfurst.org/Engine/Boostclearances/605D_clearance198.html

All I can say is that I don't find that our 109s are overmodeled given the data over there.   If anything it seems like we have one of the lesser G-14 engines and we could really use the update to a better one.

Which model would that be?

Now for some Cool-Aid, http://users.atw.hu/kurfurst/articles/MW_KvsXIV.htm

[EagleDNY]

We did another thread on the G14 here a while back - I'm thinking that we figured out that we have the medium altitude vs the high altitude model.   The G14 had 3 or 4 different variations of the DB605 that were used, and I was thinking it would have been better to have the higher altitude variant for scenarios vs B17s / B24s operating up at 25K or so.   

[Denniss]

There's no evidence suggesting the Dünnplattpropeller was in serial production nor is any production machine known to be fitted with them.
The G-14 usually had two main engines, DB605AM in standard G-14 and DB 605ASM in G-14/AS.
G-14 were sometimes fitted with DB 605AM taken out of a DB 610 (He 177 engine), except for a changed ignition timing (clearly marked in red over the engine) the performance should have been similar.
In late-war the G-14/AS was sometimes fitted with 605ASB or ASC, ASB an improved ASM and ASC with increased boost for 2000 PS

[shift8]

There's no evidence suggesting the Dünnplattpropeller was in serial production nor is any production machine known to be fitted with them.
The G-14 usually had two main engines, DB605AM in standard G-14 and DB 605ASM in G-14/AS.
G-14 were sometimes fitted with DB 605AM taken out of a DB 610 (He 177 engine), except for a changed ignition timing (clearly marked in red over the engine) the performance should have been similar.
In late-war the G-14/AS was sometimes fitted with 605ASB or ASC, ASB an improved ASM and ASC with increased boost for 2000 PS

Precisely.

[Reaper90]

He pours the drink but the glass never fills!
What foul magic is that?!
 

Foul magic, you say? 

That bottle, sir, never gets empty!

I want me some of THAT!

 

[bozon]

Foul magic, you say? 

That bottle, sir, never gets empty!

I want me some of THAT!

 

Does that mean that if you drink from the bottle it never runs dry, but you never get drunk?

[save]

Reminds me of the hitboxes of the Yak3 

Does that mean that if you drink from the bottle it never runs dry, but you never get drunk?