Spit/109 sea level speed comparisons in 1.08 beta patch

[NZtyphoon]

As for the Spitfire and Hurricane "get(ting) special treatment and are modelled in optimistic conditions?" While the British fighters are badly handicapped, what with engines blowing up after just a few minutes at higher boost settings, and badly under performing in other respects? Hardly "special treatment'', but there are some who don't mind.

[Holtzauge]

Originally Posted by NZtyphoon

As for the Spitfire and Hurricane "get(ting) special treatment and are modelled in optimistic conditions?" While the British fighters are badly handicapped, what with engines blowing up after just a few minutes at higher boost settings, and badly under performing in other respects? Hardly "special treatment'', but there are some who don't mind.

Well I would hope that any adjustment of the Me109E would be coordinated with a corresponding adjustment of the Spitfire speed: So if the Me109 was raised to around 475 Km/h for the DB601A variant at 1.3 ata then I would expect the Spitfire to get approximately 283 Mph for +6.25 boost and 314 Mph for +12 boost.

BTW, doing a rough calculation for the DB601Aa for 1.35 ata would yield circa:

v=460 x (1045/910)^(1/3)= 482 Km/h

In addition, Cambers question is interesting: How many DB601Aa were there on the Channel front? Was it a mix of DB601A1 and Aa? If so what were the proportions?

Concerning which engine to model, even given a free choise, I'm not sure I would opt for the DB601Aa: If the Spitfire uses +12 boost the 109E is outclassed down low either with the DB601A1 or Aa. On the other hand the DB601A1 with "Neue Lader" has superior altitude performance while the Aa is outclassed on both accounts. So why give up the altitude advantage for a mere 7 Km/h more on the deck when the result is still far below the 505 Km/h the Spitfire will do on +12 boost?

[Al Schlageter]

Shikhov:

But seems too early to make a final conclusion what was the 601Aa.
I'm completely satisfied of 601Aa installation on Bf109E-7 detailed example.
Quite strange plane - used Arado E-1 airframe (3380-3664 block) and equipped with rare enough Aa engine produced 3 years before.
Great example, but may be exist some more?

As far as I understand 1168 is the total Aa/Ba number were produced. Some of them were installed on Swiss and Jugoslavian Emils (153), may be some Do215B were also equipped. Abt. 1000 of rest DB601Aa were on LW hands.
Therefore a figure apeared 1000/4000 E = ~ 1/4 (like Olivier already showed).

Many thanks to Kurfurst for work and new documents - DASA sheets for DB601A-0, A-1, Aa, N. But new question was born - when tables was printed ? It seems in same time no later then mid of 1939.
Please compare with Auszuege aus Fl.datenblatt Bf109E-1, E-3 nach L.Dv.556/3 powercurves (p.22) and Tabelle.
DB601A in Dec.1939 in their final condition was enough different as if for 1937.

From another side as we can see DB601Aa really developed since 1936 and therefore no matter for auslandisch version of A-1 can't be at the time.

Paid attantion for more point:
DB601N offer too little performance growth compare with DB601Aa for
30-min settings:
Aa at 1,27 ata 1050 hp (4100 m) in manuals for foreign cust. 1025 (4200 m)
N at 1,35 ata 1050 hp (4800 - 4900 m)
I can't see difference and any reason for using highly expensive (5 times) and available in small quantity at the time 100 octane C-fuel if LW has on hands so powerfull and reliable engine as DB601Aa.

Seems something wrong in this story.

All the best.

Igor.

olefebvre (Butch2K) replies"

I don't believe the Luftwaffe intended to use the 601Aa in the 109 at first, it seems really associated with the introduction of bomb carrying 109. The reason being the increased power output of the take-off rating.

You correctly underlined the few differences between the Aa and the N, and indeed the differences are not that important. Keep in mind that the E-7 which was basically an E-4/B with droptank support was intended to use the DB601N at first. Yet the DB601N proved problem prone, and it's production was at first very slow. So i believe the introduction of the Aa on the /B and E-7 ac was a quick expedient to replace the DB601N until it proved reliable and could be really mass produced.

There were few 109 really equipped with DB601N engines, they simply did not provide any significant advantage at the time. With the introduction of the higher performance blower when the Friedrich entered production, then it provided an advantage.