Originally posted by gripen
Dear Isegrim,
Well, so far you have shown nothing which can be verified from the accurate test data.
You say that Gripen, its rather debatable that I had shown
nothing (or more, unworthy to be debated) - but what have
you have shown up to now? Nothing at all. So far, you claimed half a dozen things, not backed up any of them, but went on the claim more. Not even references, Grippy. You wont make your point any crebibly this way.
As for what is accurate and what is not, I`d like to know what exactly makes you qualified enough to decide that single handedly. Have you been, for example offered with a job by the greatest aircraft tests centres of the world, like the engineers had been who worked at RAE, Rechlin, NACA, and in TSAGI, and whom you critize ?
The Spitfire IX with the Merlin 61 performed better than the Bf 109G-2 above 25k. This can be easily verified from for example FAF test data and A&AEE data.
And is disproved by the data from Rechlin and by Tsagi. Shown already. There wasnt real difference between the G-2 and F. IX at 25k, even though the Spit climbed better at the very high alitutudes - nobody could ever see me denying that. But thats all.
'Clear advantage'? Hardly. Especially not when compared to the far more common LF IXs (4 times as many built than F. IXs), which was at speed disadvantage vs. 109G at high altitude.
In comparison with the turbocharged P-47 and P-38 the Gustav shines even more.
You mentioned A&AEE data. Interesting comparison Gripen, since probably you have read the report itself, you have some idea of the condition of the plane :
- the oil cooler flap was o/order, stuck at full open position
- coolant thermostat failed during the tests, radiators become fully open with maximum drag at 30-32k ft
- propellor blades were damaged and holed by splinters
- the plane carried a tropical filter (-10mph)
- not to mention it was already battle damaged when captured by the Brits, when it awaited for repairs and could not be evacuated as it was not airworthy at the time
Note that high altitude Spitfires used also quite similar system as GM-1 (LOX or something).
And to what extent? There were only a handful of Spit IX around in 42, Gripen, and even as much as you love to loose connection with reality, even you cant deny that:
-Gustavs were FAR more widespread in use than MkIXs during 42-43
-the use of LOX vs. the use of GM-1 was practically nonexistent in the practice - every G-1 was capable of carrying GM-1, thats 160 or so planes alone, not counting the other conversions, which also amount hundreds.
The Bf 109G-2 should be able to reach about 640-650km/h at bit over 6,5km (early spec sheets say 7km but later ones say 6,6km, which seem to be quite accurate if compared to the test data) with 1,42ata and 2800rpm in the clean condition but that power setting was not used in the beginning.
Compared to that claim, the Soviet -tested Bf 109 G-2 W.Nr. 14513
reached 665 kph at 7000m at 1,42ata, and 649 km/h with gunpods.
Rechlin reports 649 km/h at 7000m at 1,3ata.
Rechlin and Tsagi are in good agreement, in view of the expected performance increase due to higher boost; +15 km/h appears to be logical. Also supported by Datenblatter for the 109G series, which state 540 km/h at 0m at 1.42ata for the early Gustavs. In fact, IXLFs (541 km/h) and 109G-2/G-4s were remarkably well matached in this respect when running at increased boost, and again, the 109G held the speed advantage at altitude.
The G-2/trop tested by the British in bad condition attained a rated altitude of 23200 ft at 1,3ata, as per the report, that is 7071m for you.
6,6 km VDH was way too low for the G-2 and G-4, only true for the G-6, which lost quite a bit of ram effect due to the higher drag.
What exactly proves your statements?
Oh, BTW, Gripen, have you managed to find out why the Soviet curves shapes are correct (in fact they are the very best examples how the DB 605 worked)?
I already gave you a hint, Grippy, it has something to do with ram effect. Don`t disappoint me with this intellectual lazyness..
