[Karaya]

How do you really know that Russian made test with 1.3 Ata ? We have unkown condtion about Russian test or maby you have it?

In most russian data i found there is 1475 KM for 109 G-2:





See Finish G-2 test which were surly for 1.3 Ata:

http://kurfurst.org/Performance_tests/1 ... 15_en.html


And here we have for 1.3 Ata Bf 109 G-1 Rechlin:




Alse here are test for 109 G-2 Trop 1.3 Ata and 1.42 Ata

http://kurfurst.org/Tactical_trials/109 ... mPerf.html

I know that FM data not corenspond with in game performance ( see overspeed in game Tempest 11&13lbs performance, Fw 190 D-11 and D-13 ) but still i think that F and G moddels are much more realistic handling that G-2 model which is a lot of underweight. German pilots opinion and also test show that 109 G moddels had worse handling and turn performance then F series.

First off, I respect your opinion, just want to show you some of the conflicting data shown in various test reports

A lot of tests on all sides have to be taken with a grain of salt (or two)

For example, there's a British test report on a 109G-6 that shows horrible speed, climb and turn performances but fails to mention at the same time 2 very important facts:

The fact that the aircraft was rather worn out and the fact that it was carrying gondola armament which impairs almost all performance characteristics: speed, climb, turn,... no wonder the G-6 did less than spectacular!

I will see if I can dig it up, cant search for it right now as I'm not at home.

In the Finnish test report you have posted here, notice this:

During the tests, 1.3-1.32 ata and 2540 RPM was realized, though such small variations were within tolerance, the lower RPM and/or other factors appear to have somewhat impaired the supercharger`s performance, and thus may have reduced altitude performance, as seen from the performance curves : the rammed rated altitude of 6,3 km was considerably below not only the nominal value (of 7 km) of the DB 605 A, but also the typically obtained, avarage 6,6-6,7 km rated altitude. For this reason is it interesting to extrapolate the level speed curves of MT-215 to 7 km rated altitudes, which shows an extrapolated speed of ca. 650 km/h. The extrapolated values show matching result with those obtained on Bf 109G-4 WNr. 19 968, that was tested by the NII VVS in a very similiar configuration (ie. tailwheel was non-retractable in that case as well) in October 1943. This points to that the poor high altitude performance shown by MT-215 was likely to have been caused by a defective supercharger and/or lower supercharger speeds due to lower engine RPM..

as well as:

As a late production Bf 109G-2, WNr. 14 783 / MT-215 was fitted with an enlarged, non-retractable tailwheel as opposed to the previously retrractable one; this change caused -12km/h loss of speed at SL. This needs to be kept in mind when comparing the results with previous trials of the Bf 109G featuring retractable tailwheels.

Theres an error there actually as the -12km/h loss is meant for high altitudes really! At low altitudes the speed loss resulting from the fixed tail wheel is rather minimally and only in the order of ~5km/h!

So from the above extrapolated 650km/h at 7000m for a "good condition" G-4 + 12km/h for a retractable tailwheel we end up roughly at the same topspeed as depicted in IL-2 --> 662 vs 666km/h!

On topic of the Russian chart you posted:

Notice how the Bf109F-4 is quoted with a DB601E of 1350PS but at the same time with a topspeed of just 624km/h?

The Bf109F-4 reaches a topspeed of 630km/h after Rechlin tests with a DB601E at 1.3ata (1250PS at takeoff) and ~650km/h with the same engine at 1.42ata (1350PS at takeoff).

It is similar for the G-2, 1475PS (1.42ata) but 650km/h (very roughly speaking) 1.3ata performance at the same time on the chart. Seems like the Russians were just copying German manuals without cross-checking!

The other British test also has its flaws:

First of all it is a Tropical version so outfitted with a sandfilter that results in about 10-15km/h of speed loss at altitude. Furthermore it is again noted:

While these figures are in reasonably good agreement with the data obtained from other sources, the aircraft was not in perfect condition; for instance the oil radiator flap was locked open as mentionedin the extracts given above. Moreover, the figures in tables 4 ad 5 apply to the Tropical version fitted with an air-cleaner.

The other performance figures are only calculated and not out of an actual test and therefore to be regarded as speculative, especially as the British would give the G-2 only a topspeed of 395mph in clean configuration, that is 635km/h, the lowest figure I have ever seen for it! Even the G-6 is quoted as being faster than that in most tests!

And last but not least I again repeat:

It might very well be that the 109Friedrich simply is undermodelled in its handling which most test data points towards. The G-2 with a little thought seems to be very well represented both in speed, climb and turning peformance. The G-6, being only 70kg heavier in real life (thats only ~2.5% more) and slightly less aerodynamic (locked tailwheel, MG bulges) should only really differ in topspeed both at SL and at altitude, the 70kg hardly have an effect at the aircrafts handling at all!