Mixture

[Gridset]

I have been flying the russian planes a bit more lately, so naturally i have been wondering about mixture. I cant see any feedback from the engine to tell me mix is correct. If i poke my head out of the open canopy i can see the color of the exhaustflames and smoke from the engine, but is there any other way to tell if the mixture is good?

 

edit: i know how mixture and engines generally work ?

Edited February 4, 2019 by Gridset

[Heckpupper]

Mixture is a combination of oxygen and fuel that is being fed to the engine.

Lean mixture is used when fuel consumption is a concern, but the power isn't - for example on long cruises.

Rich mixture is used when fuel consumption is not a concern, but power is - for example in combat.

 

As a rule of thumb increase mixture richness when you want to go fast, and decrease it when you want to go far.

On public server where mostly you wouldn't be flying for longer than an hour you can get away with flying with full rich mixture as long as you want.

Also on some aircraft enriching the mixture will result with higher maximum manifold pressure when below max throttle height.

 

Various other aircraft also sometimes have manual mixture, but with presets (idle, lean, rich) rather than just a lever going from idle all the way to full rich.

Edited February 4, 2019 by 4./JG26_Onebad

[Voyager]

I believe he's asking about the Russian flighters which if you run it too rich at altitude, you flood the engine and lose power

 

I am curious how you handle those too. I can see the brown streams of fuel from the external view, but not sure what you'd look for, in cockpit, to determine the correct mixture from. 

[56RAF_Roblex]

The early PE2 has a pair of dials for Fuel/Air ratio.  I am told that ideally it needs to be around 0.9     I don't think the later PE2 does or any of the fighters.

Edited February 4, 2019 by 56RAF_Roblex

[Gridset]

2 minutes ago, Voyager said:

I believe he's asking about the Russian flighters which if you run it too rich at altitude, you flood the engine and lose power

 

I am curious how you handle those too. I can see the brown streams of fuel from the external view, but not sure what you'd look for, in cockpit, to determine the correct mixture from. 

Correct. I know how i would set mixture if i can look at exhaustflames and also the smoke/fuelstream. But from inside the cockpit i have no clue. I cant say that im missing out on power, but im not sure. The only thing i see happening when i change the mixture is that the engine runs hotter/colder depending on the setting, and of course the visuals of smoke/flames. In other civilian flightsims you often have a fuelflowmeter you can use when setting mixture, but not in russian fighters of ww2. Im just curious if anybody have some info on how the did it in real life?

[RedKestrel]

This is really an issue with constant speed propellers in general, even in real life. The constant speed unit on the propeller adjusts to changes in power quickly enough that you can't see the telltale hints of change in RPM or MP from reducing mixture too much. 

You can tell if you're running excessively rich by the faint black smoke trailing from your engine. But there's little indication of running too lean until you get to the point where the mixture is so lean the engine is actually running rough. Ideal mixture for fuel economy would be somewhat above that point.

On fully manual engines for best performance, I increase mixture until I see the black smoke coming from the engine, then lean bit by bit until the smoke disappears. In turning combat I just run full rich to keep the engine cool.

For best fuel economy its a little trickier. IRL pilots notes would suggest good settings for different engine regimes, but for Russian planes we're SOL unless you speak russian and can get your hands on the manual. I just use rules of thumb. I Get to the altitude I want to cruise at, set my MP and RPM to a good cruise setting (differs for each plane), set mixture to be just below black smoke level. Then, once you're level and your speed is consistent at cruise settings, I reduce the mixture until the airspeed just starts to drop. That gets me reasonable fuel economy without reducing cruising speed too much. There might be a better way but I don't know it. After a while you get a sense of good settings for altitudes and engine regimes.

And obviously if you're seeing engine power reductions (dropping MP, stuttering RPM), you're either too rich or way too lean, so adjust accordingly.

One thing about this sim is that it does not (yet) model detonation so running engines excessively lean doesn't trigger that, though it will make the engines run hot.

[THERION]

Hi all,

 

I'm not a professional on this, but as I almost fly only Russian fighters and bombers, I usually use the following rules:

 

- Startup / taxi / take-off I set the mixture to 100%

- Cruise flight I set it to 66% and this way you shouldn't see any smoke trails at all

- Air combat / emergency I set it to 100%

 

There is another advantage when flying low or on medium height (ca. 3000m) with mixture set to 66% / auto-rich:

- You are still fast enough to enter combat, but you're most likely not detected immediately or easily by the others.

- If you have to brake away from a combat, just simply dive and set mixture again to 66%, which helps you to

  disguise your escape path, especially near the ground and chances are good that the enemy looses the sight on

  you.

 

Hope, this will help you - but of course, if someone has some better suggestions, I'm eager to learn more.

 

Cheerio

[RedKestrel]

Also check the tech specs on the forum or in-game for each plane. Quite a few russian birds have auto mixture at certain settings, and the lend-lease birds often have various settings for auto-rich, auto lean, etc.

[danielprates]

Mixture has more to do with altitude than anything else, so the first concern should be to memorize the best setting for any altitude range. 

 

EDIT: that's not to say that using excess of mixture isn't useful in some situations. For instance, when mixture is too rich for the current altitude, the excess fuel is simply wasted, however it does help to cool off the engine a little more, which is a good reason to keep it in 'max'  during climb. However that is not the intended use of the mixture control in the first place. As a rule of thumb, you only keep mixture in 'max' when the manual says so; there is no useful use of enriching mixture other than very particular specific moments, since most of the time you will simply be throwing away precious fuel without a reward. Some people say you always use it enriched during combat. What if you are fighting in or above 5000m? You should be able to cool your engine enough with shutter controls, why put it on max if that only means you are shoving more fuel into the cylinders than it can possibly burn? 

 

Also note: some planes do not have a variable mixture setting (say, 35%, 80%, 23%, 99% and anything in between). They only have fixed positions (full rich, auto rich, auto lean, cutoff etc.) but since the game uses the same controls for everything,  what in one plane would be 100% in another is simply 'full rich', what in one plane is 50% in the other is "auto rich" or "auto lean" etc. (I am more or less guessing numbers here, didn't stop to check every plane).

Edited February 4, 2019 by danielprates

[Guest deleted@134347]

mig3:  keep at 50%. You can do 100% for 5 minutes (boosted).

la5:  keep at 100% with supercharger on (combat/fight) so the engine stays cool. In normal flight set it to 75-80%, without supercharger

yak1b: 100% in combat/fight. Otherwise drop it to 60-80% in leveled flight (with proper rads for cooling)

 

the other vvs planes i just look back to make sure there's no trailing black smoke. I haven't noticed any difference in performance at different levels.. so it' just a visual for me. I'm sure others can identify the reasons why not to do so...

[Jade_Monkey]

Another method would be to drop mixture till you see a drop in MP. Then take it up a notch again.

[danielprates]

And yet another method is to monitor exaust gas temperature. If it falls when raising the mixture lever, the mixture became too rich.

 

As far as I recal though, no plane in BoX has an EGT gauge, right?

[CountZero]

if your not using bosts or emergancy powers on vvs airplanes that have that you should try to have your mix set so you dont leve black trail, if its to ritch on high alts you lose on speed, no way to know your o correct mixture without looking at your back or color of exost flame, if you have wingman he can tell you when your smoking. diierant seasons and differant presures of missions make mix to ritch start on diff alttudes so you dont have certen set of altitudes like it was before, its constant ajustments to get good performamce depending on airplane. Same is with radiators, your constantly adjusting them on vvs airplanes to get max speed, only way to catch fly by wire 109s is to get max of slow vvs airplanes and that means constant work on mix and rads.

Also your easy visble to enemy if you fly to ritch.

Edited February 5, 2019 by 77.CountZero

[RedKestrel]

1 hour ago, danielprates said:

And yet another method is to monitor exaust gas temperature. If it falls when raising the mixture lever, the mixture became too rich.

 

As far as I recal though, no plane in BoX has an EGT gauge, right?

No, I don't think I've seen one. Pe-2 has 2 guages showing the fuel-air mixture going into the engines. IIRC you have to keep it at 0.8 on the guages for ideal mixture. 

 

[Nocke]

1.) set rpm to something a little below max

2.) do RAPID, but not large, changes to mixture

3.) closely watch rpms while doing so. The governor has a certain inertia. If you see a small increase in rpm for a moment (it comes quickly back to set point) you adjusted the correct way, and viceversa