Bf109G2 top speed in 1.105

[III/JG2Gustav05]

I did a test  for Bf109G2 since the radiator changing in 1.105 and Yak was also tested for comparison. All tests were done by autopilot function with 60% fuel in summer map, Bf109G2 pitch is trimmed to 70%.  

 

Bf109G2's top speed at 3500m is 491, but the speed drops to 486 finally, I guess it's due to wider radiator opening eventually.

 

Yak test 1,

Yak's both oil and water flaps are at 40%, got overheat message at 2'30'' , cannot say engine damaged till 15 mins. test stops here. top speed 485 IAS

Yak test 2,

with 40% oil flap and 65% water flap. no overheat message show up, water temp below 105C, oil temp below 100C can run at top speed 480 IAS all day long. 

 

 

So the conclusion is

G2 is faster than Yak1( overheat message show-up but no engine damage)1km/h at 3500m

G2 faster than Yak1 (w/o overheat message show-up) 6km/h in IAS about 7.1km/h in TAS at 3500m.

So my question here is does this result correlate with history data?

 

Edited November 26, 2015 by III/JG2Gustav05

[Finkeren]

Considering that we fly the G2 with a cap on its manifold pressure, I'd say that seems believable.

[Reflected]

Interesting. Even in the beta version I tested the 109 G-2. Please note that the real life 109 tests were done with the radiators manually closed (not fully though). The G-2's performance is closest to real life tests. Also, radiator drag is quite accurate too.

 

Now I can't comment on the Yak, I have no experience with it, or test data, but if it doesn't overheat and can keep up with a G-2 then it's probably something to look at.

 

PS: I did my tests at sea level, and without autopilot. Then you can trim your plane better, and also apply rudder to prevent slipping. The 109 will reach higher speeds.

[III/JG2Gustav05]

Ok, so it would be appreciated if anyone can share some Yak historical data here.

[III/JG2Gustav05]

Considering that we fly the G2 with a cap on its manifold pressure, I'd say that seems believable.

even with 1.42ata enabled it will not have too much change in this game because it can only be deployed 1 min, but in real life it actually can last about 3-5 mins instead.

Edited December 9, 2015 by III/JG2Gustav05

[Reflected]

even with 1.42ata enabled it will not have too much change in this game because it can only be deployed 1 min, but in real life is actually it can use about 3-5 mins instead.

 

Do you have any original source to prove that? Especially for the F-4. So that we can make a case.

[Reflected]

Also, I have the impression that now in the 109 G-2 the speed you can gain by applying full throttle is smaller than the speed you lose due to rad opening.

 

I mean at 1.18 ATA I can fly at 490-495 kph at sea level. It takes time to accelerate though. If I apply full throttle, I can accelerate to 510-ish, but after a minute the airbrakes open and I'm back to square one.

[6./ZG26_5tuka]

"Kennblatt für das Flugzeugmuster Bf-109 Baureihe F-1 und F-2 mit DB-601 N Motor" (1941)

 

Attention! The values collected in the table for Take off and Emergency Power may be drawn in as dashed lines. Only parts of the line's progression are to be flown due to Take off and Emergency Power duration being limited to 3 minutes.

 

Kennblatt of an Bf109 E with DB601 N from 1939:

 

Also I found this very interesting:

 

"Mercedes Benz Examination of the engine fittet to the Me109F, Me110. He113 and Macchi C200" (1942)

http://kurfurst.org/Engine/DB60x/files/Flight_16April1942_DB601N_Engine.pdf

 

[III/JG2Gustav05]

Do you have any original source to prove that? Especially for the F-4. So that we can make a case.

I saw there has some threads on Russian forum about this topic.

[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)

Every test with closed rads completely ruins the engine after about 2 minutes of closed rads, barely reaching top speed

Edited December 1, 2015 by Klaus_Mann

[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)

Every test with closed rads completely ruins the engine after about 2 minutes of closed rads, barely reaching top speed

^^1 minute of OH^^

[Matt]

How do you calculate TAS? I mean, for instance 465 kph IAS at 6 km is 621 kph TAS for you?

[Brano]

One need to know,as minimum:

1. tested plane altimeter setting

2. temperature at altitude.

 

Example:

If we asume that altimeter has been set for standard 1013,21 hPa at 0m and temperature at 7km was as per standard -30°C,then IAS of 457km/h equals TAS=659km/h

 

Easiest way is to measure distance flown using map grids in game map.

One grid is 10km.More grids,more precise is the result.

speed=distance/time

[6./ZG26_Klaus_Mann]

One need to know,as minimum:

1. tested plane altimeter setting

2. temperature at altitude.

 

Example:

If we asume that altimeter has been set for standard 1013,21 hPa at 0m and temperature at 7km was as per standard -30°C,then IAS of 457km/h equals TAS=659km/h

 

Easiest way is to measure distance flown using map grids in game map.

One grid is 10km.More grids,more precise is the result.

speed=distance/time

This is what I use. http://www.hochwarth.com/misc/AviationCalculator.html

It corrects for Mach effects etc.

Altimeter is standard atmosphere.

Edited December 1, 2015 by Klaus_Mann

[Matt]

You can't use the IAS ingame as CAS. So the calculation makes no sense.

[6./ZG26_Klaus_Mann]

You can't use the IAS ingame as CAS. So the calculation makes no sense.

The HUD shows CAS.

The indicators have all the errors necessary for realism, that's why I don't read them.

Edited December 1, 2015 by Klaus_Mann

[Matt]

OK, so in these screenshots, the indicator is showing IAS and the HUD CAS and the speeds are 100% identical, becasue the indicator doesn't have an error at 6 km altitude at any speed?

Edited December 1, 2015 by Matt

[6./ZG26_Klaus_Mann]

OK, so in this screenshot, the indicator is showing IAS and the HUD CAS and the speeds are 100% identical, becasue the indicators doesn't have an error at 6 km altitude?

1. Well. I worked backwards and the results of CAS were closest to the real world performances. In earlier Updates there was up to 2o kph in HUD and ASI.

Edited December 1, 2015 by Klaus_Mann

[Matt]

It's true, a few planes had indicators which showed the wrong speed (the G-2 was one of those), but that was confirmed to be a bug and fixed during early access or maybe a short time afterwards.

 

The HUD speed is IAS and the indicators are supposed to show the same speed and if they don'it, it's a bug (or, in some very rare cases, this is due to a limitation in texture resolution of the dial, but then the difference is only very small).

[JtD]

Nonetheless, thanks for your efforts Klaus_Mann. Very nice of you to check & provide the data.

 

It would still be good if you could take the advice on board - and save me a lot of time I don't need to spend re-testing.

[Sgt_Joch]

Ok, so it would be appreciated if anyone can share some Yak historical data here.

 

like this?

 

 

I have been reviewing Gordon, Khazanov's book and the figures for the Yak-1 in game seem pretty much right on.

 

The OP recorded max speeds of 520 kmh at sea level and 588 kmh at 3.685 km.

 

Now it is true that the june 42 test of Yak no. 1569 with a M-105PF engine (weight: 2917kg) did record a max speed of 510 kmh at sea level and 571 kmh at 3.6 km, but that test was not run at full power. No. 1569 had the new enlarged oil cooler and there was worry about overheating so the rpms were limited to 2550 at "low altitude" rather than the normal 2700 RPM limit. # 1569 recorded a climb time of 6.4 minutes to 5 km even though an earlier test of a M-105PA engined Yak-1 (weight: 2883kg) had recorded a faster time of 5.9 minutes.

 

There were two later tests of Yak-1s with M-105PF engines, one in late 42 (weight: 2900kg) which recorded a max speed of 523 kmh at sea level, 590 kmh at 3.8km and a climb time of 5.6 minutes to 5 km; and one in early 43 (weight: 2884kg) which recorded a max speed of 531 kmh at sea level, 592 kmh at 4.1 km and a climb time of 5.4 minutes to 5 km.

 

The later tests are probably more representative of what a M-105PF Yak-1 could achieve at 100% power

 

http://forum.il2sturmovik.com/topic/15231-isa-speed-testing-all-fighters-game/page-1

 

problem is even a book like Gordon/Khazanov's which is dedicated to Russian planes and based on actual WW2 Soviet trials has a lot of unanswered questions,

[JtD]

The M-105PF still developed more power at 2550rpm than at 2700rpm at see level. Just check Klimov data.

 

And later variants are still irrelevant to series 69 performance, looking at series 85 data or so is like using 109G-6 data for 109G-2 modelling. Different guns, different aerodynamic details, but so what?

[6./ZG26_Klaus_Mann]

Nonetheless, thanks for your efforts Klaus_Mann. Very nice of you to check & provide the data.

 

It would still be good if you could take the advice on board - and save me a lot of time I don't need to spend re-testing.

The HUD for some reason already show equivalent airspeed. Which means it is already corrected for compressibility effects. That's why I got incorrect results. however, this also means the ASI in the game is incorrect.

[III/JG2Gustav05]

Do you have any original source to prove that? Especially for the F-4. So that we can make a case.

I found one thread in War thunder forum mentioned this topic. https://forum.warthunder.com/index.php?/topic/155556-data-sheet-bf-109-g-2/

in post #4 a DB605 report is attached in which the engine runs at 1.42 ata for 5mins.

[Askania]

http://www.kurfurst.org/Tactical_trials/109G2_britg2trop/MET109Gtrop_tests.html

 

[6./ZG26_Klaus_Mann]

http://www.kurfurst.org/Tactical_trials/109G2_britg2trop/MET109Gtrop_tests.html

 

Hans Joachim Marseille, a famous german Ace flew the G-2 unlimited, which caused an engine malfunction, filling the cockpit with smoke, he died when his head hit the elevator on bailing out, this was on September 30.

This was one of the reasons Notleistung was then banned more strictly.

[Askania]

.This was one of the reasons Notleistung was then banned more strictly.

 

Hm.. interesting.. I've never heard about it...

 

 

"The commission’s report (Aktenzeichen 52, Br.B.Nr. 270/42)[Notes 6] concluded that the crash was caused by damage to the differential gear, which caused an oil leak. Then a number of teeth broke off the spur wheel and ignited the oil. Sabotage or human error was ruled out."

[JtD]

German aviation regulation required

 

"Increased short time power": 110% power for 1 minute

"Short time power": 100% power for 5 minutes

"Increased continuous power": 90% power for 30 minutes

"Continuous power": 80% power for unlimited time.

 

This is how all German aviation engines had to classify their engines up to 1939. The manufacturer had to guarantee operational safety for the power settings chosen. All the time limits given for German aviation engines are because of legal obligations based on these regulations, they have nothing to do with what abuse the engine could actually take.

 

This also carried on into come obscure practices like having a power lever in the 109 that actually did go to "110%" power, sticking with the nomenclature of regulation.

[III/JG2Gustav05]

obviously this 1 min note presented in manual is not restrict limit, if it's so critical like what we have currently in this game for sure German engineer will implement a tick device to auto disable it for safety concern.

[SR-F_Winger]

obviously this 1 min note presented in manual is not restrict limit, if it's so critical like what we have currently in this game for sure German engineer will implement a tick device to auto disable it for safety concern.

+1

IF i had to model how it works. I would model it like this:

aprox 1,5 min totally safe. Above that id add a random component. Lets say like every 10 seconds tick there is a % chance the engine takes damage. The amount of % chance for engine damage should increase until it reaches 100% at something like 5 to 8 minutes.

Shouldnt be so hard to implement like that and would definately come closer to the real thing.

 

Winger

[Kurfurst]

obviously this 1 min note presented in manual is not restrict limit, if it's so critical like what we have currently in this game for sure German engineer will implement a tick device to auto disable it for safety concern.

 

This 1-minute clockwork was only present on the DB 601A engined Bf 109Es, as far as I am aware - this rating was designed with take off assistance being in mind and become quickly ineffective for power increase above about 1 km altitude. So it made sense to automatically disengage it after 1 min, since the pilot took off already.

 

So IMHO the 1-min clocwork is not appliciable for Bf 109F or G.

Edited December 11, 2015 by VO101Kurfurst

[L3Pl4K]

 

 

This 1-minute clockwork was only present on the DB 601A engined Bf 109Es, as far as I am aware - this rating was designed with take off assistance being in mind and become quickly ineffective for power increase above about 1 km altitude. So it made sense to automatically disengage it after 1 min, since the pilot took off already. So IMHO the 1-min clocwork is not appliciable for Bf 109F or G.

Do you have information how long the db 601e can run Notleistung? If i remember correctly, i read a rebuilt engine must run 5 min Notleistung, before built in plane.

[Kurfurst]

Do you have information how long the db 601e can run Notleistung? If i remember correctly, i read a rebuilt engine must run 5 min Notleistung, before built in plane.

 

IIRC I checked this before but German primary plane manuals do not seem to contain the time limit, so we have to go by secondary manuals and papers like run-in instructions and British intel papers - generally speaking, the limit for maximum dry output 110% (i.e. no MW50) seems to be always defined as a 5-minute limit where stated, so I would go with that 5 limit, too.

[Reflected]

IIRC I checked this before but German primary plane manuals do not seem to contain the time limit, so we have to go by secondary manuals and papers like run-in instructions and British intel papers - generally speaking, the limit for maximum dry output 110% (i.e. no MW50) seems to be always defined as a 5-minute limit where stated, so I would go with that 5 limit, too.

If you could back this up with some documents we could get the devs to fix it. Thanks in advance!!

[Dakpilot]

Trouble is everyone will use it to its absolute maximum..the result although now will be maybe more accurate, it will be far from operationally historically accurate

 

Cheers Dakpilot

[CaK_Rumcajs]

Trouble is everyone will use it to its absolute maximum..the result although now will be maybe more accurate, it will be far from operationally historically accurate

 

Cheers Dakpilot

I assume a real Bf 109 pilot who got couple of Yaks on his 6 would gun the throttle regardless of manufacturer's time limit recommendations. There are plenty of reports of pilots who abused their engines. To name one I say Golodnikov. Golodnikov described the way they used P40s as not too friendly to engine life expectancy. And there are even reports of those who deliberately removed possible abuse protections to get as much performance as they could. Once the sim accepts the idea of always new and perfectly built AC on each spawn there is no justification for introduction of artificial limits to enforce more real like behavior.

[Dakpilot]

It is well documented that Soviet pilots abused P-40 limits, (probably one of the reasons the P-40 squadron lasted only two weeks at Stalingrad) no argument there, however what is not documented is Luftwaffe pilots burning engines on every flight doing the same, overboosting engines

 

If five minutes is allowed then that is exactly what would be used to the max every single flight in MP...it would not be a reflection of reality

 

Cheers Dakpilot

[III/JG2Gustav05]

It is well documented that Soviet pilots abused P-40 limits, (probably one of the reasons the P-40 squadron lasted only two weeks at Stalingrad) no argument there, however what is not documented is Luftwaffe pilots burning engines on every flight doing the same, overboosting engines

 

If five minutes is allowed then that is exactly what would be used to the max every single flight in MP...it would not be a reflection of reality

 

Cheers Dakpilot

On the other hand current 1 min limit also cannot reflect the reality. maybe a compromised solution lets say 3 mins is more reasonable. 

[6./ZG26_5tuka]

That's no reason to leave it as it is incase it's modeled inaccurately. If historically 5min safe operation usage can be confirmed it shall be 5min ingame.

 

In reality pilots didn't reccieve planes with shiny new engines and top polished fuselages. That's not the case ingame, though. Planes are being modeled after factory and not combat values.

Edited December 15, 2015 by Stab/JG26_5tuka

[Brano]

I can imagine the horror on forum,if devs would implement "worn out" factor into game