1. #1
    ytareh's Avatar Senior Member
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    Id like to know when to adjust prop pitch for max power/speed ...any info on engine peak power rpm for different planes ?Thanks...EG The P51 benefits massively from this kind of 'knowledge'...do the rest?
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  2. #2
    ytareh's Avatar Senior Member
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    Id like to know when to adjust prop pitch for max power/speed ...any info on engine peak power rpm for different planes ?Thanks...EG The P51 benefits massively from this kind of 'knowledge'...do the rest?
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  3. #3
    I take it you're talking about max diving speed?

    Because max level speed (accelerating from a slower speed) is and should be obtained at "100%" pitch for all CSP equipped planes in IL2.

    Many think that the best diving speed (ie above level maximum) is obtained by reducing pitch, and I've heard of at least one test which indicated that it worked, without much detail though. I haven't seen anything quantified to a useful extent.

    Be careful not to confuse the *temporary* speed boost you get from dropping pitch as anything other than momentum transfer - the engine and prop's RPM drops, and the rotational momentum is converted to the plane's forward momentum. The same effect occurs in cars - especially with older automatic transmissions, or manual transmissions, when the clutch is let out whilst the engine is spinning faster than it would for the current road speed.

    Any testing done should take this into account by setting pitch and speed before any diving or acceleration begins.
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  4. #4
    ytareh's Avatar Senior Member
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    Hmmm not exactly Julian ...Ive read online that prop pitch is like a cars manual gearbox and that changing it allows you to always keep the engine revs in the max power band ...its been suggested that staying at 100% prop pitch may be the same as trying to drive a manual gearbox transmission car in 2nd gear at 60mph (100kmh).(over revs making a lot of noice but not necessarily going as fast as possible)
    While theres no doubt that much of this stuff is dumbed down in game eg 'Magnetoes' dont actually do ANYTHING (although there are freak reports of them being damaged by gunfire)and you can fly most planes at levels that would blow the engines within minutes in real life (I did quite a bit of testing in the past and in game practically ALL planes overheat and engines malfunction in 6min (give or take 20 seconds )EXCEPT the P47 which 'lasts' roughly twice as long )
    In game the P51D is best flown at roughly 75% prop pitch ,50 inches boost and 2500rpm (dont quote me on all those) .At these settings particularly when 'launched' from a 5km alt dive it will cruise and cruise and cruise at very high speed without overheating ...sure you will get a BIT more poke out of it if you max out everything but it will overheat in no time ...I believe a "Miss Strega" is one of the leading authorities on this stuff in game having actually flown a real P51D
    So my question was where might I find out the best settings to fly other planes at ?Will they follow the 'real life ' settingsvalues pretty closely.I believe the big radial engined american fighters can be controlled pretty well using similar strategies (2250 to 2400rpm max power for "R2800"???)
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  5. #5
    I see what you're saying. Whilst it remains true that maximum power can only be attained at 100% 'pitch' (even for the R2800), I agree that if you're cruising at reduced MP, you should always lower prop RPM. It's always puzzled me as to why people don't! I did some testing in the P40 (to figure out what flight times were achievable, given its lack of in-game fuel gauge), and found that reducing RPM for cruise could give identical or better speeds than 100% pitch for a given MP, but much less fuel consumption.

    I still can't help you with a link to any guides though. I just get used to a particular plane by experimenting whilst cruising, and doing accelerated time tests for fuel usage if I'm serious. As a general rule whilst cruising, I always keep the pitch percentage lower than throttle percentage, 80/60 for example. There are no free lunches that I've found though - speed will always roll off for reduced power and pitch, it's just that some combinations give better fuel economy and engine temperature. However, I've noticed that IL-2 has (at least with the planes that I've flown) an incorrect tendency to base engine temperature off throttle percentage rather than engine power output.
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  6. #6
    Every aircraft has settings for different phases of flight. I can't really say I've seen more technically data, ie max MAP for a given prop setting, in a POH. Anyway, there are climb settings, cruise, ect... Then we run into those applying in game and I doubt that they would. I could be wrong.
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  7. #7
    If you are searching for car manual for understanding on max power/speed or any info on engine peak power rpm then you can search the online manual for the car. There are various website available like carmanuals.org where you will get full information about your concern. They have manuals for all car model for different brands.
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  8. #8
    There are lots of pilot handbooks for various aircraft that are in the game.

    I have found that the Handbook engine performance data of the Corsair and Hellcat are almost spot on with the game regarding RPM & MAP. What is incorrect for these two aircraft is the altitude recommended by Oleg of switching supercharger speeds at 18,000 ft. & 25,000 ft. The handbook (and testing in game) has the Hellcat maintain 44" Hg @ 2550 RPM (normal or max. continuous power) up to around 5000'. As you get close to 5000' MAP (you are at 100% throttle at this point) the MAP drops approximately 3" which is when you shift super charger speeds. You then maintain 49.5" MAP up to approximately 17,500 ft where it has dropped 3-4" and you switch supercharger again. Corsair is similar except that it shifts first at 7000 ft. The difference is that even though they both had R-2800 the R-2800-10 in the Hellcat had a different carburetor than the Corsair's R-2800-8.
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