Bf109G-2 underperforms at altitude

[6./ZG26_Klaus_Mann]

Just tested the G-2's top speed at 6 and 7 km of altitude.

6km: Auto Rads: 465 IAS / 621 TAS         Clsd: 484 IAS / 646 TAS According to Soviet and German sources should be 647, so pretty close

7km Auto Rads: 448 IAS / 631 TAS           Clsd: 457IAS / 643 TAS which should be 660 by Soviet and German sources, completely inacceptable

(655 can be reached by increasing rpm to 2800 manually)

Overheat message comes after 1 minute and engine is irrecoverably damaged after 1.5 minutes.

This is disappointing at best, infuriating at worst.

Edited December 1, 2015 by Klaus_Mann

[6./ZG26_Klaus_Mann]

Yak-1: 3 minutes till OH message and 2 minutes to engine destruction under the same conditions.

Edited December 1, 2015 by Klaus_Mann

[indiaciki]

could you  tell me of any reason (except for historical) why somebody would prefer the G2 over the F4? I don't get it. Maybe armament? The f-4 is a better aircraft to me, though I haven't flown the g-2 very much. I really don't know what they improved. She's heavy. The DCS K to me is a downgrade in performance just like the G-2.

Edited December 1, 2015 by indiaciki

[III/JG2Gustav05]

 

Just tested the G-2's top speed at 6 and 7 km of altitude.

6km: Auto Rads: 465 IAS / 621 TAS         Clsd: 484 IAS / 646 TAS According to Soviet and German sources should be 647, so pretty close

7km Auto Rads: 448 IAS / 631 TAS           Clsd: 457IAS / 643 TAS which should be 660 by Soviet and German sources, completely inacceptable

(655 can be reached by increasing rpm to 2800 manually)

Overheat message comes after 1 minute and engine is irrecoverably damaged after 1.5 minutes.

This is disappointing at best, infuriating at worst.

 

according to the  Rechlin Test  on G1 at 1.3 ata ( Nr. 1586E.B.Nr......./43 G.Kdos)  http://www.wwiiaircraftperformance.org/me109/me109g.html   I remember that develop team claimed that they use this document as a reference for G2 modeling.

 

Speed at 6k is 642 km/h

            at 7k is 649 km/h 

[6./ZG26_Klaus_Mann]

could you tell me of any reason (except for historical) why somebody would prefer the G2 over the F4? I don't get it. Maybe armament? The f-4 is a better aircraft to me, though I haven't flown the g-2 very much. I really don't know what they improved. She's heavy. The DCS K to me is a downgrade in performance just like the G-2.

-The G-2 should be better at continouos power, at least according to all the sources I know of, by a couple kph here and there, as well as climb speed by a considerable margin.

-The G-2 should be faster across the board except 4000-6500m where the F-4 beats it slightly.

-The G-2 should climb as well or better, by a 0.5m/s at all altitudes except 4000-6500m where they are on par, the F-4 will even catch up slightly

-The G-2 should dive better and faster and bleed less energy.

-The F-4 should be a better turner with higher rate of roll though the board, up to dive limit, where it is on par again with the G-2

-The F-4 has the Emergency Mode at which it will, for a very short time, outperform the G-2 in every aspect of performance.

 

However ingame the F-4 apparently gets a weird mix of Emergency Mode Top Speed and somewhere inbetween climb which basically means it leaves it in the dust once it deploys the afterburners, while apparently the G-2 is modelled as if it had a Non-retractable tailwheel and the rate of climb is too low with closed radiators.

In fact it's generally [Edited] due to the weird new radiator physics.

according to the Rechlin Test on G1 at 1.3 ata ( Nr. 1586E.B.Nr......./43 G.Kdos) http://www.wwiiaircraftperformance.org/me109/me109g.html I remember that develop team claimed that they use this document as a reference for G2 modeling.

 

Speed at 6k is 642 km/h

at 7k is 649 km/h

With a Non-Retractable Tailwheel. Clean Versions had about 12kph advantage. The soviet tested one did 666, while the german test at Erla with the Semi retracted tailwheel resulted in an average of 660kph. Edited December 1, 2015 by Bearcat
Language

[indiaciki]

I get it, now. I was wondering why Messerschmitt would downgrade an already good airplane....

[6./ZG26_Klaus_Mann]

I get it, now. I was wondering why Messerschmitt would downgrade an already good airplane....

The G-2 climbs too slow right now. It should do 21m/s but only ever does 20m/s with closed radiators at low altitude

The F-4 should only do 525kph at SL, but does 538, the G-2 does the 535 it should do.

The F-4 does 19.5m/s at combat power.

 

So you see how weird it is that the G-2 is exactly at or below spec in top speed, below spec in rate of climb, while the F-4 is far above spec in top speed and just in spec for rate of climb.

 

This is what the climb rate should be for the early G-series, and shows the Top Speed for the late model landing gear which reduced top speed by 12kph.

Edited December 1, 2015 by Klaus_Mann

[III/JG2Gustav05]

The G-2 climbs too slow right now. It should do 21m/s but only ever does 20m/s with closed radiators at low altitude

The F-4 should only do 525kph at SL, but does 538, the G-2 does the 535 it should do.

The F-4 does 19.5m/s at combat power.

 

So you see how weird it is that the G-2 is exactly at or below spec in top speed, below spec in rate of climb, while the F-4 is far above spec in top speed and just in spec for rate of climb.

 

This is what the climb rate should be for the early G-series, and shows the Top Speed for the late model landing gear which reduced top speed by 12kph.

which map are you using? I think that autumn map is the standard one.

[RAY-EU]

Do not worry the history average betten German vs Russian planes was 10 Russian planes destroyed vs 1 German plane destroyed .

They have to change this ... The history is in the documents and under covered ground but the winers make and change their history .

 

Germany tried to win the WW2 with the Atomic Bomb with Heinsenverg ,...as soon they get . When EEUU & only UK knows that for the cienfics that went from Europe to EEUU like Einstein , Ruddeford , Plank , Enrico Fernni ... And Japan do not knew nothing about that and Russia get it in 1949 .

 

Germany & Italy lost vs all the World , When EEUU cut to Japan the acces petrol reserves to enter the ww2 . To enter WW2 and Win EEUU bomb with B17 & 24 covering p51 mustang Geramny Factories and Germany was lost in Russia , vs East factories , the biggest Country .( like Napoleon ) .

 

Finally 1945 when EEUU destroy Nagasaki and Hiroshima with the Atomic bomb Japan and Russia do not Know nothing About That .

[Original_Uwe]

Do not worry the history average betten German vs Russian planes was 10 Russian planes destroyed vs 1 German plane destroyed .

They have to change this ... The history is in the documents and under covered ground but the winers make and change their history .

Germany tried to win the WW2 with the Atomic Bomb with Heinsenverg ,...as soon they get . When EEUU & only UK knows that for the cienfics that went from Europe to EEUU like Einstein , Ruddeford , Plank , Enrico Fernni ... And Japan do not knew nothing about that and Russia get it in 1949 .

Germany & Italy lost vs all the World , When EEUU cut to Japan the acces petrol reserves to enter the ww2 . To enter WW2 and Win EEUU bomb with B17 & 24 covering p51 mustang Geramny Factories and Germany was lost in Russia , vs East factories , the biggest Country .( like Napoleon ) .

Finally 1945 when EEUU destroy Nagasaki and Hiroshima with the Atomic bomb Japan and Russia do not Know nothing About That .

Wait...what?

[L3Pl4K]

Do not worry the history average betten German vs Russian planes was 10 Russian planes destroyed vs 1 German plane destroyed . They have to change this ... The history is in the documents and under covered ground but the winers make and change their history . Germany tried to win the WW2 with the Atomic Bomb with Heinsenverg ,...as soon they get . When EEUU & only UK knows that for the cienfics that went from Europe to EEUU like Einstein , Ruddeford , Plank , Enrico Fernni ... And Japan do not knew nothing about that and Russia get it in 1949 . Germany & Italy lost vs all the World , When EEUU cut to Japan the acces petrol reserves to enter the ww2 . To enter WW2 and Win EEUU bomb with B17 & 24 covering p51 mustang Geramny Factories and Germany was lost in Russia , vs East factories , the biggest Country .( like Napoleon ) . Finally 1945 when EEUU destroy Nagasaki and Hiroshima with the Atomic bomb Japan and Russia do not Know nothing About That .

 

:blink:  You should not sniff TDI( no, VW TDI)

Edited December 1, 2015 by L3Pl4K

[Reflected]

I also have a feeling that something is fishy with the new rad physics. It completely ruins the 109's climb rate, especially in the summer. It's like flying a glider with  In order to talk data, not feelings, would someone have the time to test climb rate ad compare it to real sources in a manner that it can be presented to the devs?

 

Caution: real climb tests were performed with rads somewhat open to avoid overheating.

[Bearcat]

Gentlemen let's not let this thread branch out into a political discussion.... Keep it historic and keep it on topic...namely 109G performance...

[6./ZG26_Klaus_Mann]

Well, the numbers the G-2 should reach, and what it reaches:

 

Should: 535kph at SL TAS, 647kph TAS at 6000m and 660 at 7000m

Does: 535 at SL, 641 TAS at 6000m with 5% radiator (Schnellflugstellung)*; 642 TAS at 7000m with 3% radiator **

 

*628 at Automatic which equals about 25% radiator (23-26)

**628 on Automatic with 22% radiator

 

Rate of climb:

Should: 18.5m/s (54 seconds from 500-1500m) on Automatic (50% radiator opening), 21m/s with radiators closed to Schnellflugstellung. This was done because the 50% setting was apparenlty too large and it could accomplish climbing with far smaller rad settings.

 

Does: 18.5m/s with 50% radiator opening, Overheats after 25 seconds from normal flight.

           19.5-20m with manual pre-cooldown and closed radiators

Edited December 1, 2015 by Klaus_Mann

[6./ZG26_Klaus_Mann]

Bf109F-4 IRL vs. Ingame:

 

Top Speed at Combat Power and closed rad.

Should: Tested: 526 at SL, 660 at 6200m 

             Calculated: 523@0 and 635@6200 calculated.

             Tested with Emergency Power: 537 at SL;  670 at 6200m

 

Does: Combat Power: 537 at SL, 635 at 6200m

                              Auto Rads 523 at SL, 625 at 6200m

            Emergency Power: 565 at SL, 660 at 6.2km

                               Auto Rads: 535 with Auto Rads, 642 at 6.2km

 

 

 

Rate of climb:

Should: 18.5m/s at 50% Rads

Does: 18.5m/s at 50% Rads

 

But with dem Top Speeds

 

Standards much?

Edited December 1, 2015 by Klaus_Mann

[Reflected]

So the g2 is too slow at altitude + it overheats too fast, even though the climb rate would be ok if not for the rads?

[6./ZG26_Klaus_Mann]

Conclusion:

Bf109G-2: -Top Speed is too low at high altitude

                 -Rate of Climb is too low with closed radiators at low altitudes

Bf109F-4: Top Speeds are all over the place and there is no coherrent standard.

 

Both have HUGE overheating issues.

Edited December 1, 2015 by Klaus_Mann

[6./ZG26_Klaus_Mann]

An Excerpt from "The Pentagon Wars" and the way I feel the Bf109F-4 beahves performancewise.

https://www.youtube.com/watch?v=iDYpRhoZqBY?t=1h11m33s

[DD_Arthur]

 

This is disappointing at best, infuriating at worst.

 

 

It is? .    Are not all these figures within the devs margin of error targets?   You do seem to spend a lot of time looking for ways to be disappointed or infuriated Klaus.

Edited December 1, 2015 by DD_Arthur

[III/JG2Gustav05]

Hello Klaus maybe it's better to measure it by using distance divided by time method like someone did before.

 

BTW, I found 1 interesting document on website WWIIAIRCFRAFTPERFORMANCE. http://www.wwiiaircr...-18-205-001.pdf

This test was done on a Bf109G6 with DB605AS engine. decreasing the cooler opening about 100mm can increase climb rate more than 1 m/S, climb time to 5km decrease from 5 min to about 4'40'' and increase level speed 25kph but the coolant temperature does not increase. so that means the radiator on Gustav is over-cooled?

Edited December 2, 2015 by III/JG2Gustav05

[6./ZG26_Klaus_Mann]

 

Hello Klaus maybe it's better to measure it by using distance divided by time method like someone did before.

 

BTW, I found 1 interesting document on website WWIIAIRCFRAFTPERFORMANCE. http://www.wwiiaircr...-18-205-001.pdf

This test was done on a Bf109G6 with DB605AS engine. decreasing the cooler opening about 100mm can increase climb rate more than 1 m/S, climb time to 5km decrease from 5 min to about 4'40'' and increase level speed 25kph but the coolant temperature does not increase. so that means the radiator on Gustav is over-cooled?

 

Distance doesn't really work when your engine dies after 1 minute on such large squares. too inaccurate.

[JtD]

You can still fly 100km at say 400 IAS without overheating, convert it to TAS using that with the map grid and then go all out and check what the 435 or so are in TAS. It should be more accurate and reliable than the online conversion.

[6./ZG26_Klaus_Mann]

You can still fly 100km at say 400 IAS without overheating, convert it to TAS using that with the map grid and then go all out and check what the 435 or so are in TAS. It should be more accurate and reliable than the online conversion.

Can you get results in the 0.2% to 0.5% range accuracy? If not, it's practically worthless.

I would just love to know what Airspeed the HUD shows, if the Devs actually bothered to tell us.

[6./ZG26_5tuka]

Another possible way (probably not too accurate)could be to create a mission with aerial route markers at certain altitudes and use the range marking as a refference for traveled distance. But I'm not very familiar with the ME and don't knwo how difficult / usefull that really is.

Edited December 2, 2015 by Stab/JG26_5tuka

[Askania]

BTW, I found 1 interesting document on website WWIIAIRCFRAFTPERFORMANCE. http://www.wwiiaircr...-18-205-001.pdf

This test was done on a Bf109G6 with DB605AS engine. decreasing the cooler opening about 100mm can increase climb rate more than 1 m/S, climb time to 5km decrease from 5 min to about 4'40'' and increase level speed 25kph but the coolant temperature does not increase. so that means the radiator on Gustav is over-cooled?

 

 

http://kurfurst.org/Performance_tests/109G_MT215/109G2_MT215.html

 

Climb rate and time.

 

Initial climb rates measured were 20.6 m/sec at SL, increasing to 24.7 m/sec at 1700m altitude. Climb to 5000m in ca. 4 min 6 secs.

 

        The climb results - 4 mins 6 seconds to 5km altitude - are in generally good agreement with the measurements of  Bf 109G-1 trials at E-Stelle Rechlin (time to 5km : 4 min 11 seconds), at ERLA Flugzeugwerke in Germany (4 min 30 secs); as well as with the results obtained with the captured  Bf 109G-2 WNr. 14 513, by the NII VVS in the USSR (4 min 24 secs).

 

        There`s, however a strong deviation, a 'spike' is displayed at ca. 1900m altitude compared to the aforementioned results, even though the shape of the climb curves follows closely the normal DB 605A-1 power curve characteristics. which develops it`s peak power output at around 2 km altitude in climbs, at the rated altitude of the supercharger`s 1. gear, or Bodenlader (M.S. gear FTH in RAF terms); all other Bf 109 test show the same phehomenon. The large scale deviation from other tests is observed from 0m up to ca. 2,5 km altitude, which prompted some, especially as it combined with a very impressive 24,7 m/sec (4860 fpm) peak climb rate for this particular Bf 109G, to dismiss the results as abberant. In contrast to the climb curve region of 0-2,5 m altitude, the curve follows closely the characteristic climb curve and values of  other Bf 109G climb tests.

 

        The test report gives the explanation to the presence of this 'spike' - the effect of the radiator flaps opening, and their varying drag, on climb rate.

 

German calculations typically assume a standard radiator flap position, referred to as Steigflugstellung (or climbing position), at which the radiator`s exit flaps (Kühlerklappen) are open 220 mm wide, or apprx. half-open, and 74mm at the variable the inlet (Einlaufflippen), in order to provide imcreased airflow during the slow-speed climbs. Such measures would keep the coolant temperature low at an optimum 85 ^○C value, but the engine itself would tolerate temperatures as much as 115 ^○C safely up to 10 minutes duration, and the automatic thermostat not interfere up to 100 ^○C temperature, which could be sustained indefinietely, as noted on page 4 of the DB 605 A-B Motoren-Karte, Ausgabe Oktober 1942 .

 

        The Steigflugstellung is assumed in the calculations up to the VDH (rated alt, FTH), after which it is assumed to gradually close to the minimum-drag Schnellflugstellung position, depicted on the right. This latter assumption was more like for practical purposes, to simplify drag calculations from the variable flap movements by assuming a constant, predictably decreasing value above the VDH, as opposed to the real-life behaviour of the automatically controlled radiator flaps which shut 1000-2500m above or even before climbing to the VDH in reality.

 

        The actual flight trials performed by Messerschmitt A.G. only vaguely follow such theoretical considerations; the position of the radiator flaps - and thus the measured performance - greatly varies between as little as 130-150mm  and wide-open as 350mm.

 

       The Finnish trials of MT-215 are no exception. The report notes that climb speeds choosen for the trials were higher (300 km/h IAS) than prescribed in the manual for optimum climb speed (280 km/h). This resulted in higher speed airflow and more effective cooling for the radiators.

As a result, it's noted that the radiator flaps would not open until the altitude of 2500 m was reached in climb, reducing drag considerably and resulting in increased rate of climb in the 0-2500 m altitude range - in short, a perfectly normal phenomenon, if we understand how airspeed, the cooling airflow, collant temperature, automatic thermostatically controlled, variable radiator exit flaps and their varying drag effects the flight performance of the Bf 109G.

 

[III/JG2Gustav05]

Askania, thank you very much for the comments. That is very interesting, so that the popular data about 109g6 taking 5'15'' to climb to 5km is likely measured with large coolant flaps opening.

[Reflected]

 

 

As a result, it's noted that the radiator flaps would not open until the altitude of 2500 m was reached in climb, reducing drag considerably and resulting in increased rate of climb in the 0-2500 m altitude range

 

Now this is what I don't understand. So the auto rads were not open until 2500 m was reached, because the engine temp didn't reach 100 C? In Bos they are wide open soon after you apply full power?

 

I've also seen the 55 kph reference, that's how much the open flaps slow the plane down. This is accurate. However, based on what was quoted above, perhaps we can conclude that the cooling efficiency of the rads for a given opening is too weak? That's what makes BoS 109s open their rads wide atomatically (thus maintaining 100C and creating realistic drag)?

[6./ZG26_Klaus_Mann]

The G-2 is just too slow, 10-5 kph above 4km.

It should be a sensible high altitude choice over the F-4, but the way it is, it isn't.

[Matt]

Since i had some time to waste

 

All done with automatic radiator and on the autumn map and calculated by flying 40 km and then calculation time used for this.

 

 

Also did one (first try) climb test (only comparing from 1000-6000 m, because i'm too lazy to time the speed right to make the 0-1000 m get correct and because it was becoming boring at 6000 m).

Again with automatic radiator, didn't have any trouble with overheating engine.

 

 

(compared to the G-1 source posted above)

 

And btw, there's no way you would've reached this speed in the previous update with automatic radiators, thanks to the wrong thermostat temperature used before.

Edited December 4, 2015 by Matt

[Reflected]

Thanks for the test, Matt! Looks like the G-2 is really spot on, well done, devs!

[6./ZG26_Klaus_Mann]

Since i had some time to waste

 

Screenshot 2015-12-04 21.38.45.png

All done with automatic radiator and on the autumn map and calculated by flying 40 km and then calculation time used for this.

 

 

Also did one (first try) climb test (only comparing from 1000-6000 m, because i'm too lazy to time the speed right to make the 0-1000 m get correct and because it was becoming boring at 6000 m).

Again with automatic radiator, didn't have any trouble with overheating engine.

 

Screenshot 2015-12-04 21.38.21.png

 

(compared to the G-1 source posted above)

 

And btw, there's no way you would've reached this speed in the previous update with automatic radiators, thanks to the wrong thermostat temperature used before.

The original early G-1 did:

0km: 535

2km: 583

4km: 624

6km: 647

7km: 660

10km: 638

 

Can you do the chart for it too?

 

http://kurfurst.org/Performance_tests/109G_MttDblatt42may/109_May42dblatt.html

Edited December 4, 2015 by -Floating-Klaus_Mann

[Holtzauge]

Concerning the G2 climb rate, there was a long discussion on this some time ago: http://forum.il2sturmovik.com/topic/6830-bf-109-g-2-climb-data/?do=findComment&comment=122853

 

At that time the BoS G2 was climbing at around 24 m/s IIRC. So if it is now doing 21 m/s that is a huge improvement but still on the high side I think. A more realistic figure (as outlined in the link) would be in the order of 19 m/s IMHO.

 

OTOH while absolute values of course are important, an even more important aspect is the relative climb rates and if the Russian birds are optimistic by a similar margin then I guess 21 m/s is close enough.

[303_Kwiatek]

Yak-1 should do 15 m/s at low alt. Fw 190 A-3 16 m/s (1.3 Ata).   Wonder how much they do in BOS?

Edited December 5, 2015 by 303_Kwiatek

[Reflected]

Yak-1 should do 15 m/s at low alt. Fw 190 A-3 16 m/s (1.3 Ata).   Wonder how much they do in BOS?

 

Mate, dig up some charts and do tests in BoS that prove it clearly. (I'm not being sarcastic or tongue in cheek here)

[Dr_Molenbeek]

Concerning the G2 climb rate, there was a long discussion on this some time ago: http://forum.il2sturmovik.com/topic/6830-bf-109-g-2-climb-data/?do=findComment&comment=122853

 

At that time the BoS G2 was climbing at around 24 m/s IIRC. So if it is now doing 21 m/s that is a huge improvement but still on the high side I think. A more realistic figure (as outlined in the link) would be in the order of 19 m/s IMHO.

 

OTOH while absolute values of course are important, an even more important aspect is the relative climb rates and if the Russian birds are optimistic by a similar margin then I guess 21 m/s is close enough.

 

If you're talking about 24m/s in winter then i don't see where's the problem, since at -15°C all planes in BoS get a +~4m/s cold boost in climb rate (well, all but the 190 above 1200m  ).

[Holtzauge]

If you're talking about 24m/s in winter then i don't see where's the problem, since at -15°C all planes in BoS get a +~4m/s cold boost in climb rate (well, all but the 190 above 1200m  ).

 Did you bother to read through the thread I linked?

 

The G2 climb rate at the time in BoS was 24 m/s at standard atmospheric conditions not winter......

 

Anyway, good to see the climb rate adjusted: Got BoS at the recent sale and it seems there have been quite a few adjustments of the FM in the right direction since then as well so I was quite pleased with my purchase. Especially since the other aspects of BoS are way better than the competition: i.e. DM, AI, WW2 scenario and let's not forget the stunning winter evening scenery.

Edited December 5, 2015 by Holtzauge

[303_Kwiatek]

Mate, dig up some charts and do tests in BoS that prove it clearly. (I'm not being sarcastic or tongue in cheek here)

 

Unfortunatety i loose interestest an readiness for these the same like for playing these sim. Occasionally i follow what's happeing here

Edited December 5, 2015 by 303_Kwiatek

[Dr_Molenbeek]

 Did you bother to read through the thread I linked?

 

I was wrong because of dates, thought it was a 2015 and not a 2014 thread.

[Holtzauge]

I was wrong because of dates, thought it was a 2015 and not a 2014 thread.

No worries!

[III/JG2Gustav05]

Concerning the G2 climb rate, there was a long discussion on this some time ago: http://forum.il2sturmovik.com/topic/6830-bf-109-g-2-climb-data/?do=findComment&comment=122853

 

At that time the BoS G2 was climbing at around 24 m/s IIRC. So if it is now doing 21 m/s that is a huge improvement but still on the high side I think. A more realistic figure (as outlined in the link) would be in the order of 19 m/s IMHO.

 

OTOH while absolute values of course are important, an even more important aspect is the relative climb rates and if the Russian birds are optimistic by a similar margin then I guess 21 m/s is close enough.

You can not fully rely on the power weight ratio for climb performance assessment, radiator position, tailwheel setting etc also impact it greatly.