Fw190A-8 vs. Ki-84 vs. LaG-7

Discussion in 'Aviation' started by Piper106, Apr 6, 2013.

  1. Piper106

    Piper106 Member

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    As the title implies, between a Fw 190A-8, a Ki-84 Hayate and the LaG-7, which fighter has the blend of characteristics that give it the best combat effectiveness against the other two in this comparison ???

    Since we are talking about late war time, for both the Fw190 and the Ki-84, assume their construction is as designed (factory workers are adequately skilled and properly fed/rested, no 'guest' workers intent on sabotage in the factory, metals and their heat treatment are up to world class peacetime standards, etc.), that fuel is both available and up to the intended octane rating, and finally that pilots have adequate flight school training as well as enough flying time in the machine they will fly in combat.

    Evaluating the Ki-84 is maybe the hardest because the raw data is so skewed by manufacturing quality issues, inadequate pilot training, fuel shortages, lack of surviving original documents, etc. I think the Ki-84 is the best of the group, but I would be interested in your opinions.
     
  2. GregP

    GregP Well-Known Member

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    Late war, give me the La-7 at low to medium altitude. They made about 1,500 or so in WWII and only lost 281 to all causes inclduing mechanical, and that's while flying in Russia in the field against the Germans. Best low-to-medium altitude performer.

    I'd say the Ki-84 is better above 15,000 feet ... maybe 12,500 feet. It is faster than the Fw 190A-8, has a 50 - 60% better climb rate, and turns better, with roll going to the Fw 190A-8. On the deck, La-7 all the way.

    It's tough that the Fw 190A-8 comes in third, but you didn't say Fw 190D-9 or D-11, you said A-8. The F would come in even lower.

    I know there are a lot of Fw fans out there (me too ...), but these are three top dogs and the A-8 isn't the best Fw 190.
     
  3. cherry blossom

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    #3 cherry blossom, Apr 7, 2013
    Last edited: Apr 7, 2013
    Lets start by stating the obvious: these three aircraft are optimised for rather different roles. The La-7 was a short range fighter, the Fw 190 A8 was well armoured and armed to intercept the 8th AAF's raids and the Ki-84 was originally designed to a specification that gave it more than double the range of the other two although it also ended up as an interceptor. Thus the Ki-84 would be much more effective at escorting bombers to a target 400 miles from its bases. I am not sure exactly how much fuel a Ki-84 could carry internally. I suspect 740 litres but the prototypes probably had larger non-self-sealing tanks. Meanwhile, the Fw 190 would be more effective in attacking boxes of B-17s.

    A second point is that Fw 190 A9 rather than the A8 was roughly contemporary to the La-7 and Ki-84. It is true that A8 production continued until the factories were captured but I think that La-5FN production also continued well into 1945. Additionally, the La-7 was grounded as late as October 1944 after its first combat use due to wing spar failures. There is however one great advantage in comparing with the A8 in that we have performance figures for the A8. By contrast, the A9 may have received different engines during its short production history which may, or may not, have produced significantly more than 2,000 ps as emergency power (http://www.ww2aircraft.net/forum/aircraft-requests/focke-wulf-190-9-f-9-a-612-2.html, Fw 190 A-9 performance with BMW 801F-1 and Fw 190 A-10 | Forums - Page 2). At least most sources seem to agree that the A9 had a higher rated altitude than an A8.

    The performance of the Ki-84 is similarly shrouded in deep confusion. However, some things are fairly clear. The “low” performance numbers often quoted refer to initial models with the Ha-45 model 11. It seems very likely that a Ki-84 with a Ha-45 model 21 or 23 will go faster especially if it has exhaust ejectors. One collection of musings is at Return to Faq. The important point is that there is not a single Ki-84 to compare but rather that the design evolved over 1944-5.

    To answer the original question, a La-7 would probably win a low level fight against either opponent once its various wing and engine bugs were worked out. However, a Fw 190 A9 would be superior about 6,000 m and might be superior below if it really was ever fitted with an engine giving 2,200 plus hp. A well built and maintained Ki-84 fitted with a Ha-45 model 23 could also give a La-7 a hard time especially if it could use lower wing loading and would in theory be able to keep turning until a La-7 ran out of fuel.
     
  4. Milosh

    Milosh Well-Known Member

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    Beginning Sept 1944 to war end, some 2980 Fw190A-8s and 930 Fw190A-9s were produced.
     
  5. Piper106

    Piper106 Member

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    If I am understanding this correctly, the LaG-7 is the 'best' below 6000 meters by a small??? margin. That combat advantage has to be balanced against small fuel capacity (does anyone have a number for how many liters were onboard a LaG-7 ??) and short radius of action compared to the other two fighters

    Saying the same thing differently, none of the three has an "overwhelming" advantage in speed or manuverablity over the other two, and a superior pilot(s), starting from a tactical advantage, and surprise or plain dumb luck could tip the balance in favor of any one of the three.
     
  6. GregP

    GregP Well-Known Member

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    Aerial combat didn't usually last long enough for the fuel to run out for the Lavochkins since they weer fighting realtively close to their base. Their bases moved with the troops.

    If you are still dogfighting after 5 minutes you are probably hit, damaged, or about to be hit or damaged ... unless you are fighting one-on-one with your opponent. That didn't happen very often on the Eastern Front, especially against Russians, who flew in packs by the time they got their Lavochkins. If there was a range issue, it was a German issue because if the Russian pilots abaondoned their ground units for very long, they would likely be reprimanded if they landed back at base. Their primary job was to support the gound units.
     
  7. CORSNING

    CORSNING Active Member

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    Piper106,
    I completely agree with cherry blossom in post #3 that the Fw-190A-9 was the contemporary of the other fighters and that they were all optimized for different rolls. Greg P is right from the information I have that the fw-190A-8 comes in a dead third place as far as overall performance. Your statement in post #5 about superior pilot, tactical advantage, surprise and dumb luck tipping the balance is very true. The F4u-5 shooting down a Mig-15 in Korea proves that.

    The A-8 and A-9 with many technical improvement were still the same basic design that entered combat in August 1941. Contemporaries of the other two would be the Ki-43-1 and the early Lagg-3. So it seems to me if you are trying to compare the best performing version from each lineage the Fw-190D-9 is the logical choice in this comparison. I did a little research on these A/C. My findings combined with your post #1 requirement turned out like this:
    Information for the La-7 came from the NII-VVS test trials of A/C No. 452132-76. Information for the Ki-84-1a is from TAIC 156A report. Information for the Fw-190s come from performance test graphs in Dietmar Hermann's "Long nose". Height is given in 1000 meter increments. Speed is mph. Climb is fpm.

    HEIGHT.......La-7...........Ki-84-1a.....Fw-190D-9..Fw-190A-8
    sea level.....383/4762....362/4275....380/4428....350/3444
    .1,000........397/4762....379/4350....392/4388....359/3316
    .2,000........411/3936....389/3890....404/4124....357/2773
    .3,000........408/3660....389/3570....409/4103....369/2617
    .4,000........401/2952....388/3590....419/3985....383/2578
    .5,000........405/2952....414/3610....429/3493....397/2548
    .6,000........418/2499....426/3350....429/2991....402/2420
    .7,000........414/2007....426/2870....422/2499....393/1800
    .8,000........405/1495....416/2280....416/1987....380/1505
    .9,000........396/-984....403/1720....406/1485....365/1033
    10,000.......N.G/-472....387/1175.....394/-984....348/-580
    Weight.......7,144 lbs....7,940 lbs......9,592 lbs....9,084 lbs.
    Power........1,850 hp.....2,040 hp......2,240 hp.....1,800 hp.
    LOADS:
    Wing...........37.80.........35.13..........48.69..........46.12.....(lbs/sq.ft.)
    Power..........3.862.........3.892..........4.282..........5.047.....(lbs/hp.)

    Maximum velocities were La-7: 421mph/20,500ft. Ki-84-1a: 427mph/20,000ft. Fw-190D-9: 436mph/18,040ft. Fw-190A-8: 405mph/18,040ft.

    The Fw-190A-8 did have some advantages over its opponents: Ease of flight operation, Ruggedness, Firepower. Its disadvantages were its high wing load and power load.

    In Pilaski's book the VVS considered the La-7s roll rate to be similar to the Fw-190A.
    In Dietmar Hermann's book he states that the D-9 could make tighter turns than the A before the onset of flow separation. Major Dr. Heinz Lang states that the D-9 was somewhat inferior in turn to the A.
     
  8. delcyros

    delcyros Well-Known Member

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    Note that La-7 No. 452132-76 from the NII-VVS acceptance trial is dated april 1945 and not representative for very many pre-VE-day manufactured La-7 to appear on the front. I suggest to use data from august 1944 La7 serial No.452101-39 to get representative figures.
    Similarely, TAIC records for Ki-84 were done on a machine specially prepared and tuned, run on higher than usual grade fuels. Japanese trials were lower than that.
    Why are Fw-190A8 data given withotu boost?
     
  9. tomo pauk

    tomo pauk Creator of Interesting Threads

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    #9 tomo pauk, Apr 13, 2013
    Last edited: Apr 13, 2013
    Why would Americans specially prepare tune the Ki-84 (or any other captured plane)? Is that mentioned in the TAIC records?
    The better fuel cannot increase power/speed at altitudes greater than critical altitudes, and we can see here the Ki-84 performing exceptionally well at 7 km, or roughly at military rating critical altitude, 2nd gear, with ram. It's also a performer above that altitude.

    One might say that Ki-84 is sorta mistery. There is lot of unknowns claims, different engines (1800 HP are mentioned in prototype, serial example were equipped with 2000 HP), number of the engines unable to perform as advertised, lack or, later, presence of individual exhaust stacks, were the Japanese performing their tests on conservative engine rating vs. Allied testing with emergency ratings... In other words, a 100% performing Ki-84 might as well do 425mph, but 100% performing Ki-84s were not the majority one could encounter when flying over East Asia in 1944-45.

    Seems like the A8 data is with over-boost (when applicable).

    a81.JPG
     
  10. delcyros

    delcyros Well-Known Member

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    RG mentioned various modifications on the fuel lines, the cylinders and mixture controll with replacement parts beeing specifically manufactured in the US in context with the Ki-84 tested in the US. He went so ar to suggest that the modifiations in connection with the 100/150 grade fuel allowed higher than usual boost pressures beeing utilized in the A/C, resulting in appreciably better performance than with 75/85 octane fuels used by the japanese. In fact, the US Ki-84 trials used forced WEP on 10 minutes to develop max. speed, something the A/C was never cleared for operation in japanese airforces.

    Japanese data only give military rating for their A/C. This is understandable, as the fuel grade wouldn´t allow for max boost levels to be utlilised for more than 60 sec. at anything else than SL+1000m.
    Certainly sure is that the Ki-84 was rated at 345mph on the deck and 388 to 392 mph at +250 boost in optimum altitude (military rating). It has been suggested that speed on WEP would be temporarely higher had the Ki-84 made use of Water injection on the Ha-45-11 engine or forced on better fuel grade. However, note that it appears from various sources that the engine had restrictions preventing it from using WEP until late in the war (and even then for only 1 minute rather than 5 on the La-7 or 10 on the Fw-190A) due to low grade fuels and water injection was never implemented.

    My guess? The engine was producing 1600hp at +250 (military rating), resulting in ~390 mph. On 1 minute WEP it could be forced to 1800 hp @ + 350 boost, providing it was cleared for this in 45. Assuming the WEP could be engaged long enough to stabilize on a new max. speed (1 minute is to short for this, but the US trial may have been long enough), the cube root rule from 1800/1600 allows the estimation of a top speed of roughly ~405mph, not accounting for ram effects and increased full pressure height.

    Thanks for the table. I stand corrected.
     
  11. cimmex

    cimmex Member

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    Where does this datasheet come from? I’ve never seen an original datasheet from any German plane dated during WWII in English. Unlikely that this paper was provided by the Focke Wulf Company.
    cimmex
     
  12. Juha

    Juha Well-Known Member

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    #12 Juha, Apr 14, 2013
    Last edited: Apr 14, 2013
    Probably translated from original. There are several performance charts on Fw-190As in Mike Williams site, but also elsewhere.

    PS Checked from Mike's site and there is almost the same that Tomo posted in German, look update on 18 May 2008. Removed my attached image, because similar can be found in Mike's site.
     
  13. cimmex

    cimmex Member

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    Sure, the sheet was translated from an original document and the data seems correct. But why it is not mentioned translated and by whom and done to give a lookalike as an original. Credible sources should always provide the original document together with the translation otherwise there is always a bad smell.
    cimmex
     
  14. CORSNING

    CORSNING Active Member

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    #14 CORSNING, Apr 14, 2013
    Last edited: Apr 14, 2013
    Thanks for the help tomo. The A-8 figures are with the use of C3 fuel and 1.65 ata boost and the D-9 figures are with B4 fuel, 1.8ata boost and MW-50. I am not an authority on aviation fuel, but I think fuel used by the Japanese was 92 octane.


    Thanks, Jeff
     
  15. Juha

    Juha Well-Known Member

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    #15 Juha, Apr 14, 2013
    Last edited: Apr 14, 2013
    Hello Jeff
    yes the main Japanese high octane fuel was 91 or 92 oct and they did introduce 95/110+ octane fuel in 1944 for some fighters. And some specialists have said that Japanese offcial figures are garanted, in other words the min attainable max speed for a new plane in service when usually official max speed figures are with +/-3% tolerance, meaning that officially 650km/h plane achieving 630,5km/h was still accepted.

    Juha
     
  16. CORSNING

    CORSNING Active Member

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    Good morning Juha, thank you for the information concerning fuel from Japan. That brings us to focus on the original post by Piper106, (......."that fuel is both available and up to the intended octane rating").
    Does anyone have a graph or chart showing the climb rate of the Fw-190A-9? All I have is a speed chart from Deitmar Harmann's "Longnose" which the following figures are taken:
    HEIGHT......Fw-190A-9
    Sea level...368
    .1,000......381
    ,2,000......379
    .3,000......378
    .4,000......393
    .5,000......407
    .6,000......414
    Maximum: 416mph/17,300ft. Flight weight of 9,636 lbs.
    BMW 801(?) (???? HP) using C3 fuel and a boost of 1.82ata.

    The best climb rates for this airframe I have found are from Mike Williams' sight for the Fw-190G-3 two gun version at a weight of 8,535 lbs.
    4,000 fpm/4,000ft.

    Thanks, Jeff
     
  17. tomo pauk

    tomo pauk Creator of Interesting Threads

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    #17 tomo pauk, Apr 14, 2013
    Last edited: Apr 14, 2013
    It comes form easily available translated manual about the Fw-190A-8. The translation was done some time in 1980s IIRC (correction welcomed).

    Hopefully the bad smell will go away.
    Of course, always complaining about this or that thread, or this or that item on this forum, while avoiding any kind of positive contribution, can provide it's own hefty amount of bad smell, too.

    Note that the speed of the A-9 is without C3 over-boost in the attached chart.

    chart speed fw190ta152.jpg
     
  18. tomo pauk

    tomo pauk Creator of Interesting Threads

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    Interesting; were those modifications made because the specific engine (engines?) have malfunctions, being worn-out war-time ones, or all Homares needed specified treatment?

    It's awkward to debate about the posts, presumption and assessments made by a person no longer member here. But several things are questionable.
    Namely, the engineers in the USA knew well that Homare was operating at 91 oct fuel (and such kind of fuel was in US use, mainly for training units, and maybe for transports?), so the 75/85 oct figure is out. The use of 100 oct and better fuel can delay the onset of detonation, but cannot do anything for supercharger hi-alt capabilities. As reckoned in BoB, RAF's Merlins were providing the same power either on 87 or 100 oct fuel above plane's rated altitude, since that's where supercharger's limits are in play.
    The test of the Homare with 100/130 oct fuel does not make sense, since it would produce results different to the real hardware the US enemy have had in time.

    Maybe you could provide some info about both things mentioned here, along with RG's posts about the Homare?

    That's where the ADI comes into play. The cheap way to circumvent the unavailability of higher grade fuel, used by many combatants, mostly by Germans. Hayate did have ADI, as did the Raiden and Shinden.

    Again, I'd like to ask you to point me out to that data. The military power was 1695 HP at 21000 ft, on 91 oct fuel (scroll down for source), and the modestly-sized Hayate should have no problems to easily outpace any Hellcat and Corsair (bar F4U-4) without any problems, and by comfortable margin. We can add the much better layout of the exhaust stubs as an icing on the cake.

    Same as above, I'd like to see the sources about the ADI being never implemented.

    The 1600 HP on Hayate should be able to beat even the light-weight Fw-190A-3, (let alone the heavy A-8, both on non-restricted 801D, at Notleistung), since the Hayate would have had 10% more power available, the weight and drag being in the ballpark. So maybe we could speak about ~415 mph for the Hayate on military.
    The WEP was available at altitudes lower than military power, thicker air there meaning more drag. So the speed could not be directly calculated on cube root law. The Fw-190A-8 and A-9 were maybe 10-15 km/h faster with SonderNotleistung than at Notlesitung, so for our Hayate the speed increase might be up to 10 mph?

    Some discussion about the Homare and Hayate here:
    http://www.ww2aircraft.net/forum/engines/nakajama-ha-45-hamore-engine-32694-2.html - includes the US test of the Homare on 91 oct fuel, along with power data
    http://www.ww2aircraft.net/forum/flight-test-data/ki-84-homare-u-s-12795.html#post516389
     
  19. FLYBOYJ

    FLYBOYJ "THE GREAT GAZOO"
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    My question as well, and I'd like to know the SPECIFIC mods done. Were larger diameter fuel lines installed? Stainless steel? Aluminum? The mixture control, was it altered internally? Cylinders - over-sized?
     
  20. Shortround6

    Shortround6 Well-Known Member

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    I would note that the P&W R-1830 operating on 91/98 octane fuel could use 48in manifold pressure at sea level for take-off. 42in is about 6lbs boost and 48in is about 9lbs boost. The pressures being used by the Homare don't seem to be out of line with a reasonable estimate of allowable operating pressure for the fuel available.

    I would also note that even with 100/130 fuel available it takes a mighty brave (or foolish) test pilot to over boost an engine in flight that has not previously been tested on the ground in the over boosted condition. And that is the ONLY way 100/130 fuel is going to give more power, by using higher boost and higher pressure inside the cylinders.
     
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