Messerschmitt Bf.109 Performance Chronology

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To post a thing or two about the Bf-109F1/F2.
1st, the power graph for the BD-601N, that shows the 'Steig kampfleistung' being at 1,25 ata (max) and 2400 rpm; the 'Start Notleistung' (1 min here) at 1,35 ata (max) and 2600 rpm. Respective power at altitude being 1050 PS at 4850m abd 1175 PS at 4900m.



However, the Kennblat for the BF-101F1/F2 says that 'S. Notleistung' is allowed for 3 minutes there, with the manifold pressure increased to 1,42 ata. The manifold pressure for the 'Steig Kampleistung' increased to 1,30 ata. Max speed being 615 and 595 km/h, respectively; see the 'Wirklich' (='True') arrow:



This is not yet as far (fast) as the Bf-109F1/F2 was capable for. The over-revving to 2800 rpm was allowed, that gave another 10-15 km/h at rated height. That means 625-630 km/h.



We still don't know what power was available for the F1/F2, though. The footnote from the latest doc might lead as to the answer. It reads, roughly, that when Kampfleistung is at 1,25 ata instead of 1,30 ata, the power is down by 4,5%. For the Notleistung, when the manifold pressure is at 1,35 ata vs. 1,42 ata, the power is down by 6%. Going backwards, the power should be around 1100 PS on Kampfleistung and 1250 PS on Notleistung. The cost was probably several hundred meters in the rated altitude vs. what the graph shows us, ie. the rated altitude was at, roughly, 4500 m for those power settings, no ram.

The over-revving helped considerably for high altitude power and performance, but I still don't know for certain the power available for 2800 rpm, that was allowed at and above rated altitude. My guess is that some 100 PS would be the gain at ~5 km ( no ram), ie. some 1270 PS there.
 
Hello Tomo Pauk, many thanks for the feedback.

I will modify the graph. As you said, 1.7 + MW 30 is missleading.


IIRC During Soviet tests the 109 tended to overheat, thus I do not think the test is as reliable as Finnish or Germans. In any case, the graph shows that there was little improvement in performance from F-2/4 to G-6.

Is there any tests with G-10 performance available? This G version was popular with pilots, and should have a performance comparable to K-4 at 1.80ata.
 
Please note that some of the curves are based on DB/Mtt testflights where they did something to the supercharger slip system. These graphs look like the the higher speed supercharger gear kicking-in at full speed and not controlled via the fluid coupling.
 
Speed curve should be smooth (similar to the G-2 curve) and not showing the zigzag of two-speed superchargers
 
I have now included the Bf 109 G-10 performance. The only test I found came from a Soviet source, which I assume in turn took it from a German one. See link below. There are no data on engine settings or weight. The book just says it is equipped with a DB "605DC engine". Data only go to 8000 meters.



In many discussions it has been stated that G-10 was the most popular late variant of the 109, preferred to K4 because it did not have the underwing tubs and the MG 151 20mm gun instead of the 30mm MK-108. However, is there any specific pilot/s that made the claim? I have only read about Uffz. Georg Genth from JG 26.
 
I think 1.42ata on db605a was not banned. Fire problem on 1.42ata was fixed in early or mid 1943, but it was not fully propagated at front until early 1944. German Bf109G handbuch was published for both(fixed and not fixed) aircrafts. I think this is right interpretation. How do you think guys?
 
I'm afraid you're wrong on this. The 'Start and Notleistung' (2800 rpm AND 1,42 ata) setting was banned for circa a full year, from autumn of 1942 till autumn of 1943. There is plenty of data at Kurfurst's that prove it.
 
The G-10 curve looks valid, that's the smooth curve you expect from the hydraulically changed supercharger speed on DB engines. Have not yet checked the speeds though but on the first glance they look ok.
 
interesting thread that I found
Bf-109G-6/U3 and Bf-109G-14/AS, where are they? | Forums - Page 2

not sure of the validity of what was stated AND it as a decade old...
says the/U3s went to Recon units, suppose a prelude to Bf109G-8 recon version
if I read things right, the /U2 GM1-equipped, when field converted to MW50 were still /U2 technically (???).... and of course Gf109G-6 w/MW50, no matter you call it, lead right to the production Bf109G-14.

also an interesting relted thread on TOCH
ME 109g-6 u4 arnaments? - Page 3 - Luftwaffe and Allied Air Forces Discussion Forum


BUT, in PRIEN p108, says it is an easy conversion from GM1 to MW50 thus making Bf109G-6/U2 into Bf109G6/U3, a 'common' conversion. does not say RECON FIGHTER

I'm confused
 
The /U2 stayed /U2 even when converted to MW50 use. The G-6MW was a different beast with built-in MW50 system. AFAIR /U2 used compressed air from bottles to feed GM1/MW whereas G-6MW used bleed air from the supercharger for this.
 
Not impossible to have recons with MW, the MW system just had a smaller tank due to limited space. With MW tank the camera installation may have been limited in size as well.
The G-6/R2 had MW system, AFAIR cams were only for low alt recon.
 
When looking at the graph previously created it is possible to see the performance increment of G-10 at high altitude compared to G-6/G-14. The issue is that G-10 came quite late in 1944, around October. How did other G6/AS and G14/AS compare? These versions should have been introduced before G10 and helped against high altitude Allied fighters, like P-47/P-51.

The only performance graph for G14AS I have seen is in the link below, but no details on configuration and weight have been provided.

kriegstechnik: Bf109G-14AS vs Bf109G-14
 
When looking at the graph previously created it is possible to see the performance increment of G-10 at high altitude compared to G-6/G-14. The issue is that G-10 came quite late in 1944, around October. How did other G6/AS and G14/AS compare? These versions should have been introduced before G10 and helped against high altitude Allied fighters, like P-47/P-51.

The only performance graph for G14AS I have seen is in the link below, but no details on configuration and weight have been provided.

kriegstechnik: Bf109G-14AS vs Bf109G-14
 
G-14/AS and G-10 should have a very similar performance. The graph may show maxspeed of the /AS at a bit too high alt, AFAIR it should be roughly 1 km below rated alt of 7.8 km.
Speeds are too high for gunboats.
 
Is the graph from flight tests or calculated like those in Kuffies link?
Somewhat irritating to see the G-6 with 605A 130kg heavier than the G-5 with 605AS - gunboat?
-> Kuffies data has the /AS heavier by 35kg.
 

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