Fw-190 Prototype engine changes

[HellToupee]

I think it´s pretty safe to challenge this statement. The Bf-109F struggled over France? If so, then no less than the Fw-190. As a matter of fact, the RAF had a very negative fighter exchange ratio versus Bf-109F and Fw-190A over France and particularely vs Bf-109 over Malta and North Afrika in the 1941 to 1942 timeframe. I can only see an empirical but no statistical justification to make this claim. The Fw-190 impressed the RAF because it was something new. Had they been able to test a Bf-109F4 in good condition, they would have been more impressed wrt performances.
The soviets tested both and found the Fw-190A beeing less dangerous than the Bf-109F/G of this timeframe.

Spit V and 109f were quite evenly matched for performance, spitfire pilots were extremely confident engaging 109s since it matched its performance and exceeded it in manoverability, where as 190 performed better also was highly manoverable with its roll rate and an elevator that responded at high speeds.

 

[KrazyKraut]

The same would go vice versa. The 109 pilots were also pretty confident they could take on the Spitfire V. But the 190 had a certain edge in the altitudes that counted most in 1942 and was extremely well armed and less prone to frontal damage which both helped enormously against the RAF bombers used at the time.

 

[The Basket]

The He 100 was dropped even though in my opinion it was a genuine contender. The DB601 was marked for the 109/110.

I thought the Fw 190 only got the nod because it didn't use the DB or it may have shared the He 100 fate. It was not a replacement for the 109...it was a second iron in the fire...so to speak.

 

[delcyros]

The main task of the fighter force on the western front (France) was defending against RAF attacks, combined fighter and bomber attacks. The 109F was, performance-wise, more or less evenly matched against the Spitfire

How so? The Bf-109F2 perhaps but the Bf-109F4 was significantly better than the Spit V in level speed, acceleration and climb performance. I have never seen a speed figure for any Spitfire V variant showing a faster speed than 375 mp/h. The corresponding figure for the -F4 with 1.42 ata was in the region of 404 to 416 mp/h.

Speculation. They did evaluate the rather similar 109 G-2 and it didn't impress them as much as the Fw did.

No Bf-109G2 was ever tested by the RAE. They got a modified Bf-109G6/R6 Wilde Sau nightfighter with gunpods and additional equipment which has nothing to do with a Bf-109F4 in relation to performances.
The only Bf-109G2 tested by allied intellegence units was one tested by the VVS, which had a top speed of 414 mp/h, despite engine problems. And yes, appearently its performances impressed the VVS.

Speculation. The DB603 was one of Daimlers high priority projects, so I think it was sufficiently pressed, maybe even more so than the BMW801. The 801 simply matured faster.

High priority? That´s laughable, KK.
The Db-603 was begun in 1936 but the RLM effectively stopped funding of the program in 1937. The engine continued under PRIVATE FUNDING in within the Daimler Benz company until a reassesment was done inspite of the 2800 hp delivered at benchtests in 1939. RLM reauthorized funding of the engine in early 1940. So in between 1937 and 1940, the Db-603 was a low priority engine without any funding provided by the gouvernment.

Could've been investigated? Yes. Would've been production ready earlier than 1943? No.

The first 120 Db-603 were produced in 1941, so basically yes, it could have been forced into production earlier.

 

[HellToupee]

How so? The Bf-109F2 perhaps but the Bf-109F4 was significantly better than the Spit V in level speed, acceleration and climb performance. I have never seen a speed figure for any Spitfire V variant showing a faster speed than 375 mp/h. The corresponding figure for the -F4 with 1.42 ata was in the region of 404 to 416 mp/h.

Most sources give 390 as the top for the f4. As it was 109f and spit v were considered evenly matched.

No Bf-109G2 was ever tested by the RAE.

allies captured a 109g2 in North Africa.

 

[Vincenzo]

Most sources give 390 as the top for the f4. As it was 109f and spit v were considered evenly matched.



allies captured a 109g2 in North Africa.

395 mph it's the speed before of 1.42 ata
the G2 was trop variant and had some trouble, was good for a captured plane

 

[Colin1]

I have never seen a speed figure for any Spitfire V variant showing a faster speed than 375 mp/h. The corresponding figure for the -F4 with 1.42 ata was in the region of 404 to 416 mp/h

I'm interested in where you got these figures from.
I can't find satisfactory concensus over the maximum speed of the F-4; these range from 354 to 390mph. The higher figures seem to be representative of maximum emergency speed and the lower figures normal combat speed.

The only Bf-109G2 tested by allied intelligence units was one tested by the VVS, which had a top speed of 414 mp/h, despite engine problems

Again, that seems ambitious, I can't find anything that puts the G-2 over 400mph.

By the way, you don't need to say mp/h; the 'p' and the '/' mean the same thing
so you are saying 'miles per per hour' (I think in Europe you are used to saying km/h)

 

[HoHun]

Hi Colin,

>I can't find satisfactory concensus over the maximum speed of the F-4; these range from 354 to 390mph. The higher figures seem to be representative of maximum emergency speed and the lower figures normal combat speed.

Here is a diagram showing some conflicting figures for the Friedrich.

The blue line shows data from an RAF intelligence report.

The green lines are from a US report on the Me 109F-2 which makes an estimate both of the F-4 top speed and of the DB601E power curve. (The top speed curve and the power curve from the report don't even remotely match each other.)

The red line is the official German Kennblatt data for the F-2. Obviously, the F-4 with a more powerful engine would be faster than this.

(The RAF/US report figures seem to be often quoted for the Friedrich, but they are obviously not very trustworthy.)

Regards,

Henning (HoHun)

 

[KrazyKraut]

No Bf-109G2 was ever tested by the RAE. They got a modified Bf-109G6/R6 Wilde Sau nightfighter with gunpods and additional equipment which has nothing to do with a Bf-109F4 in relation to performances.
The only Bf-109G2 tested by allied intellegence units was one tested by the VVS, which had a top speed of 414 mp/h, despite engine problems. And yes, appearently its performances impressed the VVS.

I'm sure you know about the Black Six. Sure, it's a Trop but it's similar enough. It weighs more and has a more powerful engine (compromised by the filter) and apparently had a fixed tailwheel (alhough that wasn't necessarily so for all G-2s). Other than that the airframe is similar. Overall, performance-wise, the G-2 Trop should be very close to the F-4, but probably a tad less maneouverable.

High priority? That´s laughable, KK.
The Db-603 was begun in 1936 but the RLM effectively stopped funding of the program in 1937. The engine continued under PRIVATE FUNDING in within the Daimler Benz company until a reassesment was done inspite of the 2800 hp delivered at benchtests in 1939. RLM reauthorized funding of the engine in early 1940. So in between 1937 and 1940, the Db-603 was a low priority engine without any funding provided by the gouvernment.

I said it had a priority within Daimler not within the RLM, but yeah that was stretching it. It doesn't matter anyways. The BMW801 was as reliable in 1941 as the DB603 was only in 1943. That's the facts and all what if's and if not's won't change it.

The first 120 Db-603 were produced in 1941, so basically yes, it could have been forced into production earlier.

Hmm, I wonder then why it took them until 1944 to get them anywhere near the desired 100 hours between MROs. That was all after official funding was back to normal.

 

[Colin1]

Hi Colin
The red line is the official German Kennblatt data for the F-2. Obviously, the F-4 with a more powerful engine would be faster than this

Thanks Henning
these graphs of yours are useful
According to Kennblatt, the F-2 tipped in at around 370mph, so the F-4 came in at between 35 and 50mph faster for (roughly) the same airframe? Surely, if it was actually the case, the top end of this estimate would be at emergency power?

 

[Vincenzo]

kennbatt of F-2 was a combat power (30 min), the top for F-4, slight less 50 mph faster, yes it's a emergency power

 

[davebender]

30 minutes is a long time for aerial combat. The Me-109 would probably run out of fuel before the engine blows up.

 

[HoHun]

Hi Colin,

>According to Kennblatt, the F-2 tipped in at around 370mph, so the F-4 came in at between 35 and 50mph faster for (roughly) the same airframe?

You have to take into account that the Me 109F-1/2 Kennblatt speeds are for the DB601N at 1.3 ata, 2400 rpm while in actual operations the engine was downrated to 1.25 ata, 2400 rpm for climb and combat power (30 min rating).

The DB601E of the Me 109F-4 on the other hand ran at 1.3 ata, 2500 rpm for climb and combat power (30 min rating), giving 1200 HP at 4900 m (static altitude) compared to 1105 HP at 4400 of the DB601N.

If I extrapolate Me 109F-4 performance from Me 109F-1/2 performance, assuming drag did not change between the two versions, I get 627 km/h @ 5.7 km for the combat power setting and 636 km/h @ 5.85 km for the emergency power setting (1.42 ata, 2700 rpm).

This might not be the final word on the issue as there is some uncertainty recording the amount of exhaust thrust, but at least it gives a pretty good general idea of what one can expect from the up-engined Friedrich.

Regards,

Henning (HoHun)

 

[Colin1]

If I extrapolate Me 109F-4 performance from Me 109F-1/2 performance, assuming drag did not change between the two versions, I get 627 km/h @ 5.7 km for the combat power setting and 636 km/h @ 5.85 km for the emergency power setting (1.42 ata, 2700 rpm)

Thanks for that Henning
That's 390 and 395'ish mph for the F-4
That's feasible, very respectable and more in line with what I'd expect from any of the F series Bf109s. I'd need some hard data to convince me that any of them could nudge 420mph.

 

[Vincenzo]

Hohun surely you know of F-4 test with 660/670 km/h,
for F-1/2 i don't know deutsch but the speed AFAIK was
595 km/h (2400 rpm 1.3 ata),
615 km/h (2600 rpm 1.42 ata),
almost 625 km/h (2800 idk ata)
at time of kennblatt, maybe oktober, 1941, the engine was underated at 1.25 ata and 1.35 ata for the first two (no info on 3rd). idk if the engine take never the full power.
the speed of G-1 was 410 mph (from the datenblatt), was 405 mph (from kennblatt 2600 rpm 1.3 ata) the G-2 it's same plane w/o pressurization,

 

[Colin1]

Hohun surely you know of F-4 test with 660/670 km/h

I've never seen a report suggesting the Bf109F had anything like that kind of a speed advantage over the Spitfire Mk V; 416mph - that's Fw190A-4 territory and faster than most of the other A series Focke-wulf a/c.

 

[delcyros]

I stand corrected with the G2 / lack Six. This A/C was not in good condition when found in the desert. It had signs of battledamage on the hub and propeller, malfunctioning radiator flaps and tropic filters. The VVS test result for a clean G2 does match (666 Km/h) well the Rechlin trials which showed 660 km/h top speed for the G-2.
Furtherly, in comparison with the F4, the G2 was significantly heavier. It´s about 250 Kg difference in take off weight (F-4: 2.850 Kg, G2: 3.100 Kg).
Michael Rausch´s site is my source for speeds of the F4 with 1.42ata:
Beim-Zeugmeister: Page 1 - Introduction
The Bf-109F4 was tested at Rechlin and the JG-26 (with operationally front line fighters) vs early version Fw-190A and was found to be faster at altitudes larger than 4000m. This includes the top speed (15-20 Km/h faster than the Fw-190A2, IIRC -these figures also point to the correctness of the 670 km/h top speed of the F4 / 650 Km/h of the Fw-90A2).
The OKL overview of fighters dating to 1942 puts the F4 at 670 Km/h/6200m.
Independent VVS tests between Bf-109F and Fw-190A confirm that the Fw-190A was slower.
That is not the fastest Bf-109F4. According to M. Rausch, there is evidence suggesting that the GM-1 augmented -F4/z could go past 700 Km/h at altitude.
Kurfürst has suggested that these values may be without position error correction/compressibility correction. If so, the same applies to BF-109G2 and FW-190A.

Hennig, Your speed graphs appear to be a bit on the conservative side.
According to them the Bf-109F2 is slower than the aerodynamically less clean and db-601 powered 1939 Bf-109E (Baubeschreibung gives a top speed of 500 km/h for the -109E at SL and 1175 hp). I would estimate the 1941 F-2 beeing significantly faster than this due to better power and less drag. The british F2 AFDU test does only give about 485 Km/h for the F2 which is even slower than Bf-109E and thus only representative for this individual plane and it´s state, not the standart 109F2.
SL top speed for the -109F1/2 acc. to Kennblatt is 495 Km&h @ climb combat power and 510 Km/h at take off power.
The completely worn out Bf-109F2 Werknr.9209 tested by the Tsagi (it was repaired at least four times before beeing belly landed with the right leg and wingtip broken. Even after repairs, the supercharger was malfunctioning and the engine considered to be near worn out, too) was found to achieve top speeds of 597 to 600 Km/h at altitude, which are in good agreement with german sources. It was reported that at ground level, the F2 was substantially faster than the -109E tested beforehand.
The bf-109F4 with 1.42 ata should be significantly faster than this.

 

[delcyros]

I said it had a priority within Daimler not within the RLM, but yeah that was stretching it. It doesn't matter anyways. The BMW801 was as reliable in 1941 as the DB603 was only in 1943. That's the facts and all what if's and if not's won't change it.
(...)
Hmm, I wonder then why it took them until 1944 to get them anywhere near the desired 100 hours between MROs. That was all after official funding was back to normal.

Are You familar with the BMW-801C MRO intervals? If 100 hours was the desired MRO interval to qualify for operationally reliable engines, then the -801C cannot be considered RELIABLE by 1941, too. Correct me, if Im wrong. The december 1941 state of Fw-190 engine reliability required 25 hours MRO intervals.
Note that the fourth and fifth Db-603 prototypes produced in 1939 running on Water-methanol producing 3000 hp for the speed record car trial abandoned by outbreak of war. By this time, no -801 was even benchtested.

 

[davebender]

When did that become available? Was it an add on kit for existing Me-109F4s?

 

[Vincenzo]

30 minutes is a long time for aerial combat. The Me-109 would probably run out of fuel before the engine blows up.

at example F-4 consume 350 l/h at combat power (30 min.) and have 400 liter so it's not as you told