revisit the DB605 Engine and BF109 G-6 flight model

[the_emperor]

Type of improvement: Historical accuracy/accurate flight/engine model

Explanation of proposals:

The DB605A Engine FTHs are rated at

5800m without ram (kein Stau) and 6600m with ram (level flight) for the 1.3ata/2600rpm and 1.42ata/2800rpm setting.

The G-6 top speed at FTH 6600 is rated at 630kmh/2600rpm and 640kmh/2800rpm.

Neither the engine nor the plane ratings can be achived.

(Airspeeds converted: https://aerotoolbox.com/airspeed-conversions/

Equivalent Airspeed: 432kmh/2600rpm/6600m;  444kmh/2800rpm/6600 -> True Airspeed: 609kmh/2600rpm/6600m ; 626kmh/2800rpm/6600

Edit: I was light on fuel. A full fuel tank reduces the true top airspeed by approx. 4kmh)

Tested on the Rheinland Autumn map

 

Benefits: historical accurate flight model

 

Edited February 15, 2021 by the_emperor

[FTC_ChilliBalls]

Just asking, but what were your elevator trim settings? Those have a significant impact on top speed.

[NIK14]

Stop the presses!

Yes...this is a major historical inaccuracy...let's focus on this.

 

Nevermind the seemingly titanium reinforced tailplane of the whole 109 series.

[CountZero]

I run test at 6600m on Kuban autumn QM airstart (devs use this map as refrence if i remenber corectly), 50% fuel, stab trim = 90% , auto rads, auto rpm, auto level.

84% throtle ( combat max ) after ~7min , in game panelshows 437kmh

100% throtle ( emerg max ) up to timer expired, in game panel shows 447kmh

(For example if i use spring kuban map i get 438kmh, and 448kmh, if i use BoBp winter map i get 440kmh, and 450kmh (453 on 0% rad))

 

Using TAS converter and Kuban autumn speeds from game it looks like:

combat max = 616 kmh

emergancy max = 630 kmh

 

If i aditionaly use manual 0% rad:
combat max = 441 kmh = 621.5 kmh
emergancy max = 451 kmh = 635.6 kmh

 

For testing emergancy I first go to max combat speed, and then go to max emergancy in same flight.
For testing with manual rads i first go to max on auto and then turn on manual and go to 0% untill engine brakes or speed dont go up.

 

 

 

Edited February 21, 2021 by CountZero

[the_emperor]

@CountZero thank you very much, if the Kuban Autunm map is the reference point I will use that for further testing.

You said you were using 84% throttle. If I am not wrong that is more than 2600rpm?

I tested the DB605A to its manual Setting Kampfleistung: 1.3ata/2600rpm (~80%throttle) but only achived 1.2ata at 6600m and 1.42ata/2800 but only achived 1.38ata at 6600. 

@So_ein_Feuerball 75% but I will look if more trim will bring better results.

Enginethrottle and rads where set on automatic. next testing will be with ~350l fuel to compensate for climb to altidude

Thank you all for your constructive input :-)

[CountZero]

15 minutes ago, the_emperor said:

@CountZero thank you very much, if the Kuban Autunm map is the reference point I will use that for further testing.

You said you were using 84% throttle. If I am not wrong that is more than 2600rpm?

I tested the DB605A to its manual Setting Kampfleistung: 1.3ata/2600rpm (~80%throttle) but only achived 1.2ata at 6600m and 1.42ata/2800 but only achived 1.38ata at 6600. 

@So_ein_Feuerball 75% but I will look if more trim will bring better results.

Enginethrottle and rads where set on automatic. next testing will be with ~350l fuel to compensate for climb to altidude

Thank you all for your constructive input ?

Yes its more ata or rpm but thats what game tells me its max combat mod, so untill they fix it i go by that ( its same error on most axis airplanes).

Yes i also get max of ~1.38 ata on 100%

For stab/trim i see around 90% is best at that alt.

Edited February 21, 2021 by CountZero

[the_emperor]

Tested on Kuban autumn:

Engine and Rads on auto, Stab trim at 90%, fuel 340l, altitude 6600m
2600rpm: only 1.2ata. indicated airspeed: 435kmh ->~ 613kmh true airspeed

2800rpm: only 1.38ata. indicated airspeed 446kmh -> ~ 629kmh true airspeed

 

I did a climb test and the supercharger pressure starts to drop between 3500m and 4000m.

There might be something wrong with the ingame FTHs for the DB605A engine (and maybe for the DB605AM engine too?, which FTH is rated 4000m ohne Stau (without ram) at 1.7ata/2800rpm and 5000m with ram in level flight).

 

Cheers

Edited February 22, 2021 by the_emperor