Bf109 test data

[Robo.]

Thank you very much for the info about the superchargers, superb!

Originally Posted by Kurfürst

Depends. Engines have higher FTH in high speed flight. An Aa should get about 3700m in climb and 4800 m in full speed flight (the latter being a bit problematic with the current poor altitude model)

I am aware of RAM effect, but the current FTH in the sim (for all Emils) is 4,5km in the climb. (I would need to re-check that in the current beta patch.)

[Winger]

Originally Posted by *Buzzsaw*

Salute

Nothing is ever simple, there are no easy ways to arrive at 109 performance figures which are 'exact'.

The German figures are qualified with a note that different engines of the same type, (DB601A, N, etc.) can vary from +2.5/-2.5 percentage difference in engine horsepower output. That can easily add up to 20 kilometers per hour difference between different aircraft when we are talking about top speed at altitude.

The British, American and Swiss figures are done with aircraft which are either captured or export variants, which might or might not perform up to German standards.

In addition, often tests are done at different boost levels, or with radiators either open or shut.

Some of the German documents may or may not have figures which are inflated, as they are intended to provide information for potential foreign buyers, and obviously a higher performance aircraft is more likely to sell.

All of the above means that one has to be VERY careful in the study of the various tests/figures, and not jump to hasty conclusions.

What we do know is that the 109E was a very competitive and dangerous aircraft, capable of taking on the Hurricane and Spitfire in the aerial combat arena. And vice versa.

You could also change the "German" to "English" here...

[Kurfürst]

Originally Posted by *Buzzsaw*

Salute

You are suggesting this is a test of a different reduction gear?

Because in fact the speeds shown are achieved at a boost of 1.15 ata.

Oh, my bad, didn't scroll down LOL.

[Kurfürst]

Originally Posted by Robo.

Thank you very much for the info about the superchargers, superb!

You are welcome.

I am aware of RAM effect, but the current FTH in the sim (for all Emils) is 4,5km in the climb. (I would need to re-check that in the current beta patch.)

Oh, something is fuzzy then... indeed it looks like the neue Lader, I wonder if someone has the most recent engine file data, I remember seeing them on the forum some time ago.

[Al Schlageter]

Originally Posted by Winger

You could also change the "German" to "English" here...

You do have examples you can post, yes?

[csThor]

On the Bf 109 E-3/b, E-4/b and E-7 and the engine thingy. Do not distinguish the bomb carriers too much, especially not when talking about the engine. IIRC not a single E-3/b was produced (unsurprising since the E-3 went out of production even before the Luftwaffe even thought about using the 109 as Jabo) so any potential aircraft of that type would be converts. Although this is somewhat doubtful since they would most likely be upgraded to E-4 standards at the same time and labeled E-4/b afterwards, anyway.

IMO the E-4 (and E-4/b) would be the most probable candidates for the 601Aa while E-1 and E-3 should feature the 601A. IMO, of course.

[41Sqn_Banks]

According to rather old FM files there is a DB601A and DB601Aa. The Bf 109 uses the DB601A, only the He-111 P uses the DB601Aa.

Both engines have the same FTH (4500m), max boost (1.35) and WEB (1.45) values. The difference that I found:
- DB601Aa has a higher ramming factor
- DB601Aa has a constant speed propeller

[Kurfürst]

Buzzsaw,

To answer your questions about the V15a, yes its an E-1, but no, I do not think there was any meaningful difference between the E-1 and E-3 aerodynamically. Only the fitted armament was different. Now one of the test you have posted show that there was 0 to 1 kph "difference" between the MG FF being present or not.Other than that there was a slight bulge under the cannon drum in the underside of the wing. I do not know what drag that was responsible for, but I do have British tests for the Spitfire which give a speed difference of a whopping 1 mph for the similar bulge for the Hispano ammo drums...

As for the V15a test, the full paper has been transcribed on my site
http://kurfurst.org/Performance_test...w_109V15a.html

and I have also recently uploaded the originals to this forum, you can find in one of my recent postings in another thread.

As for the 3 papers you have posted, they are turn times and radii for the 109E at 0 and 6000m, at various flap settings.

[Robo.]

Originally Posted by 41Sqn_Banks

According to rather old FM files there is a DB601A and DB601Aa. The Bf 109 uses the DB601A, only the He-111 P uses the DB601Aa.

Both engines have the same FTH (4500m), max boost (1.35) and WEB (1.45) values. The difference that I found:
- DB601Aa has a higher ramming factor
- DB601Aa has a constant speed propeller

So it is safe to state that the DB601 family is not modelled correctly regarding FTHs and max MAPs and the engine of any Emil in the sim is a mix of both Aa and A-1.

[Robo.]

Originally Posted by csThor

On the Bf 109 E-3/b, E-4/b and E-7 and the engine thingy. Do not distinguish the bomb carriers too much, especially not when talking about the engine. IIRC not a single E-3/b was produced (unsurprising since the E-3 went out of production even before the Luftwaffe even thought about using the 109 as Jabo) so any potential aircraft of that type would be converts. Although this is somewhat doubtful since they would most likely be upgraded to E-4 standards at the same time and labeled E-4/b afterwards, anyway.

IMO the E-4 (and E-4/b) would be the most probable candidates for the 601Aa while E-1 and E-3 should feature the 601A. IMO, of course.

There was a theory that the Aa low alt performance (take-off HP) was desirable for the JaBo variants and therefore Aa DBs were primarily used for /B variants. Only 25% 601s were Aas. This theory is supported by the fact that every JaBo 109 examined after being shot down has had Aa engine (AND the bomb rack installed.) I am aware that this is just a theory and it is not mine after all, but it makes sense.

Maybe you are right and the numerous engine overhauls would cause for majority of the later BoB Emils flying with Aas despite the lower overall number of 601 made (e.g. one airframe could have several engines installed during its lifespan). What we have now is a DB 601 with A-1 FTH and Aa rating, that is certainly incorrect.