1. #1
    Viper2005_'s Avatar Senior Member
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    The Mustang III is too fast at altitude.

    It appears that it has 81" Hg performance whilst only drawing 70" Hg. This isn't just a boost gauge issue, as the supercharger gear change takes place at the wrong height too.

    At 81" Hg (+25 psi boost) full throttle height in MS gear should be about 8,000 feet, with supercharger gear change taking place at around 12,000 feet. Full throttle height in FS gear should be around 20,000-21,000 feet.

    In game, supercharger gear change takes place at about 15,000 feet which is exactly what one might expect were the engine rated at 70" Hg.

    Full throttle height in FS gear in game is about 25,000 feet.

    This means that excessive performance is available between about 8,000 feet and 15,000 feet, and again above about 20,000 feet. By 25,000 (7500 m) feet the aircraft is capable of very excessive speeds (~770 km/h according to wonder woman view on the crimea map).

    It seems that the P-51C was given extra power to turn it into a Mustang III without alteration of the engine's full throttle height.

    <span class="ev_code_RED">This issue is especially important if we're going to get a +25 psi Spitfire as the same pitfall awaits.</span>

    Source:
    http://www.spitfireperformance.com/m...stangtest.html
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  2. #2
    Brain32's Avatar Senior Member
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    You did not say P51 was best at everything and you even try to prevent same thing happening with the mew Spitfire, now watch your thread being ignored.
    I for one completely agree with you, this issu has been mentioned before and Robban made the tests: http://forums.ubi.com/eve/forums/a/t...3/m/7321095783
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  3. #3
    robban75's Avatar Senior Member
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    Originally posted by Brain32:
    Robban made the tests:
    I'd just like to add that I have always made tests with wind and turbulence on. For speeds without wind, detract 6-8km/h from the top speed.

    The speed test below is made without wind and turbulence.

    Crimea, full fuel default loadout, rads closed. In meters and km/h(TAS).

    Mustang III

    SL - 650
    1K - 675
    2K - 705
    3K - 730
    4K - 730
    5K - 720
    6K - 760
    7K - 771

    The Mustang III, as well as P-51B/C/D, lose between 40 and 60(!) km/h in top speed with wing racks fitted!
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  4. #4
    robban75's Avatar Senior Member
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    Originally posted by Skunk241981:
    Airspeed isnt dependant on wind. So with or without wind you would get the exact same figures.
    IAS isn't, but TAS is affected(in-game) when wind is turned on.

    For example, with wind I get 621km/h at sealevel with the D-9'45. With wind off I get 612km/h. Perhaps true airspeed really is ground speed.
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  5. #5
    Willey's Avatar Senior Member
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    621 in the 45? I always thought the 44 was faster, like the real one - and like the previous FB versions... should test them again, as well as the P-47 25lb vs the D-27 (can't see any speed and climb difference there, at least up to 3k)
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  6. #6
    Viper2005_'s Avatar Senior Member
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    I've posted a thread on the warclouds forums including a zipped track.

    http://www.war-clouds.com/forums/vie...hp?p=3937#3937
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  7. #7
    p1ngu666's Avatar Senior Member
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    i didnt know it was too good up high

    770 kph = 478.455818 mph

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  8. #8
    Von_Rat's Avatar Senior Member
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    doesn't that make it faster than the ta152, even at the ta's best alt.

    in other words its faster at 7500m than the ta152 is at its best alt, which is 9000m.
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  9. #9
    VW-IceFire's Avatar Senior Member
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    As I understand it...the real overboosted aircraft gained performance at low altitudes and gain some performance all the way upto their best rated critical altitude and above that they were the same as the lower boosted versions.

    This is true of the Spitfire LF.IX with 150 fuel/+25lb boost. I imagine this is also true of the Mustang Mark III with the same type of configuration. So the guess here is that the game is boosting power above best speed/critical altitude as well as at lower altitudes.

    Am I correct? Does the graph only diverge after rated critical altitude?
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  10. #10
    http://www.spitfireperformance.com/merlin66hpchart.jpg

    The HP produced converges as it becomes supercharger limited rather than engine durability limited. You can see the big difference it would make at certain altitudes. At 12,000' a +25lb boosted engine is producing over 400 hp more than the +18lb engine. But there is no difference at 20,000' and beyond because the engine then becomes supercharger limited. So above 20,000' the Mustang III shouldn't be any faster than your stock standard boosted Mustang.

    EDIT: I just took out the picture from spitfireperformance because I realised it had a big "do not distribute or copy" on it. You can just click on the link to look at it now
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