Yak-1 mixture settings "Power"

[arrow_man]

Did testing for myself and figured others may find this useful.

Below are the maximum power mixture settings for the yak 1. I would assume they would be the same for the lagg 3 but I haven't tested

Altitudes have been rounded to the nearest 100th and mixture settings give some room between settings.

 

Tested at 2650rpm and maximum throttle

 

85% 50-2000m

75% with Supercharger second gear 2000-4000m

60% 4000-5000m

45% 5000-5900m

35% 5900-6500m

25% 6500-7100m

15% 7100-7900m

5% 7900-8800m

0% +8800(If you don't fall out of the sky from lack of airspeed)

Edited September 8, 2015 by Iron_Knight

[JtD]

I find this interesting, but how did you determine "maximum" power? Top speeds?

[arrow_man]

Exaust flame color. 

Yellow rich, blue with yellow tips is where you are getting the correct mixture, blue and white is lean(can use for fuel saving).

No changes for the 2 extreme ends.  Too rich at atlitude will cause very rough engine, extreme lean will just incresase heat and possibly kill the engine.(worst case is pre ignition wich will damage the engine).

 

Pretty much I stuck my pilots head out the side while I played around with the mixture and alltidues for a few hours.(poor guy must be frozen).

 

The settings are set up so they overlap a little and for user friendliness. For example I tried 80% but I found I was running lean at very low altitude but didn't need to touch it till 2400ish.  The supercharger also effects the air ratio.

I found 85 was perfect for 50 to 2000. By then I usually switch the SC to second so it made sense to do that and lean the mixture at the same time.

 

85 is yellow above 2000 with gear 1 but with gear 2 its optimal.  But then I started wondering how much I could lean it out while I was changing gears becasue then I wouldn't have to worry about leaning it as much at higher alltidues

I found 75 was perfect for 2000 and a bit under, 70 was too lean.

 

Just kept climbing till the flame changed from blue and yellow to pure yellow then would find a setting that worked for that altitude and overlapped abit under it.

[Brano]

Thats just the visuals.Issue is,that altitude does not effect rpm in game.I dont know if this has been addressed yet by devs.Didnt try that for months.

In real life,pilots of yak/lagg were not looking at color of the exhaust flames,but engaged vysotnyi korektor when rpms started to oscilate.It was also part of the training for high altitude flights.Pilot was supposed to lean the mixture untill he saw oscilation in engines rpm and then push the lever just a bit towards rich to get optimum output.

 

Vysotny korrektor should not be engaged = should stay in position "full rich" up to 4km for M105PF.That is the max altitude where supercharger at 2nd stage can provide fuel mixture ratios as set for ground level by your mechanic.Only at hights above 4km you should start "leaning" the mixture,as supercharger is losing power and there is less and less air provided for fuel mixture = you have to lean fuel ratio as well.

Edited September 8, 2015 by Brano

[arrow_man]

Correct me if I am mistaken but don't one of SYN_Requiem's guides state this.

 

Yes you don't have to lean the mixture until it becomes rough but you aren't getting the best air to fuel ratio when burning enriched either.

 

[Brano]

Those are lines from Yak pilot manual.Rule is simple.Do not engage vysotni korrektor below 4km.

1. Mechanic will set up your M105PF at ground for best performance.

2. This setup is kept up to 4km with the help of 2stage supercharger.

3. Above 4km you have to modify amount of fuel going into mixture.Less air,less fuel.

 

Ofcourse you can play with corrector even below 4k for economy flight,but in war conditions it was seldomly used.Klimov engines were set up to run at full sustainable power output.With enough cooling you could run it on 2700rpm with max manifold pressure for entire lenght of the flight.In real,the problem was that "enough cooling" as it was often not enough

[Gump]

is this true for other russian planes as well? i was flying formation with a few pe-2's the other day at about 800m alt, and i was being left behind until i adjusted mixture up to 100%, then another formation pilot informed me that i had sped up. i think i had the mixture set at about 80%. didnt look at the speedo

[LukeFF]

Yes

[Finkeren]

is this true for other russian planes as well? i was flying formation with a few pe-2's the other day at about 800m alt, and i was being left behind until i adjusted mixture up to 100%, then another formation pilot informed me that i had sped up. i think i had the mixture set at about 80%. didnt look at the speedo

The Yak-1, LaGG-3 and Pe-2 in BoS all have the same engine, M-105PF, and 2-gear supercharger, meaning that apart from the cooling and details about the propeller (which I don't even know is modeled and to what degree) their engine management is exactly the same.

 

The AM-38 on the IL-2 is slightly more temperatmental and doesn't like to be run at full throttle for the entire length of the flight. IIRC it also only has one supercharger gear, but since you pretty much have no reason to ever fly the IL-2 higher than a few thousand feet, you never really have to touch either supercharger nor mixture.

 

The Shvetsov engines on the La-5 and I-16 operate much the same way, though obviously the La-5s engine is much more powerful and generally harder to keep cool. They can run at full throttle all day with no issue, but the I-16 has a tendency to push its RPM too far up in a dive (indicated by a diplay of 'boosted mode' in the technochat), which can lead to damage. Both can run with the extra boost (forsazh) for a limited period of 5 - 10 minutes during which the engine gets quite hot.

Edited September 11, 2015 by Finkeren