All-Aircraft-Simulations
Mixture? - Printable Version

+- All-Aircraft-Simulations (https://allaircraftsimulations.com)
+-- Forum: IL2 MODS Download & Discussion (https://allaircraftsimulations.com/forumdisplay.php?fid=267)
+--- Forum: IL-2 4.09m (https://allaircraftsimulations.com/forumdisplay.php?fid=348)
+---- Forum: IL2 MODS Discussion Section 4.09m (https://allaircraftsimulations.com/forumdisplay.php?fid=292)
+---- Thread: Mixture? (/showthread.php?tid=58834)


Mixture? - dihedral - 18.01.2009

Hi All!

Just noticed something strange with the Mixture settings in the game offline. I was returning from a mission in a Lightning and noticed my fuel begin to run low-so I tried to lean it out. The plane didn't respond to my commands and I ended up in the water off Guadacanal. I ended the mission and then checked the control gui in the game and the mixture lean and rich are both assigned. I then check my Lightning Cockpit on the tarmac and the mix levers don't move when either lean or enrich is pushed. They seem to be stuck in full rich. All other control levers move and function as they always have. I tried this in 6 other planes in the meantime and the mixture control doesn't work in any of them. I have complex engine management turned on. Is this a bug? Flying longrange missions on the Slot map really need good fuel management. Anyone else notice this?

- walter_solito - 18.01.2009

Good observation I'll check and report soon!

walter

- bolox - 18.01.2009

mixture control is only available ingame to planes without (in real life) an auto mixture function. therefore most aircraft ingame can't use it- by most i mean most us,british an german fighters. most russian planes have mixture control as does iirc he111 and a few others. some planes have a 'max rich' (110%)setting available - wildcat? for instance. been this way ingame pretty well from day one

to economise on fuel in planes without mixture control you could try setting prop pitch to something other than 100%- more revs=higher fuel consumption. try using max cruise settings from r/l manual- roughly 2000 rpm and 30-34 inches manifold pressure for us planes is a ballpark figure

- Murph - 18.01.2009

Just to clarify things- in US planes, "prop pitch" actually means RPM setting. Almost all US planes used auto mix and constant speed props.
Yes, setting a lower RPM will conserve fuel. In fact, it's not a bad idea to use this when heading outbound to target, if you're not in too much of a hurry. It might keep you from running low on the return trip.

- walter_solito - 18.01.2009

Hi!

No bugs for me , I agree with previous reply , you must to reduce RPM to a max cruise value by setting prop pitch and throttle to mantain a selected speed (a bit above stall speed in clear configuration (Vcruise=Clear Stall Speed+10/15%).

1) Set RPM to cruise value

2) reduce pitch a bit (rpm rise a bit)

3) reduce throttle to gain previous cruise rpm

Check speed:

- if a bit over clear configuration stall speed now you are in low fuel consumption;

- if again too high repeat procedure from nr.2

CHEERS and a long long flight!

walter

- dihedral - 18.01.2009

Thanks all for your replies! I've just been trying out my KI43 and sure enough the mixture leans as it should. But as regards the us fighters and the Lightning in particular, I seem to remember reading that Lindberg was sent into the PTO to teach the Lightning Jockies how to get the most in range and endurance out of the A/C. So surely if it's at all possible it would be great to have the mixture levers activated for the sake of realism. Lindberg wouldn't just have told them reduce the rpm. They never would have got Yamamoto for instance that way. Or at least, they never would have made it back afterwards!

- .041 Safety Wire - 18.01.2009

Technically lowering rpm does not conserve fuel. lowering manifold pressure does as the manifold pressure determines power output.

- Guardian12 - 18.01.2009

dihedral Wrote:Thanks all for your replies! I've just been trying out my KI43 and sure enough the mixture leans as it should. But as regards the us fighters and the Lightning in particular, I seem to remember reading that Lindberg was sent into the PTO to teach the Lightning Jockies how to get the most in range and endurance out of the A/C. So surely if it's at all possible it would be great to have the mixture levers activated for the sake of realism. Lindberg wouldn't just have told them reduce the rpm. They never would have got Yamamoto for instance that way. Or at least, they never would have made it back afterwards!

I agree. I think that the player should have realistic controls over the plane, if that is what he/she wants. I wish that someone would make a mod for this.

- rollnloop - 19.01.2009

AutoLean position for throttle would be nice to have, but still, right now, when using flight manual figures for minimum specific consuption, it works !

For the P-38J figures from the manual are

20000ft 31 manifold 1700 RPM
10000ft 29 manifold 1600 RPM

Try these, you should see a sigifnicant difference in fuel consumption (about only 25% of what you use at military power !)

- caldrail - 19.01.2009

Internal cobustion engines suffer a problem with aeroplanes, and thats the thinning of air as you go higher. Since the engine is delivering a certain amount of fuel according to the throttle settling, as the air thins out at higher altitudes the amount of oxygen to cobust is lessened. For that reason, aero-engines include a mixture control to reduce the amount of fuel for any given throttle setting, thus keeping the fuel/air ratio at its most efficient.

Some engines have devices that do this automatically (as you found).

- .041 Safety Wire - 19.01.2009

rollnloop Wrote:AutoLean position for throttle would be nice to have, but still, right now, when using flight manual figures for minimum specific consuption, it works !

For the P-38J figures from the manual are

20000ft 31 manifold 1700 RPM
10000ft 29 manifold 1600 RPM

Try these, you should see a sigifnicant difference in fuel consumption (about only 25% of what you use at military power !)

Autolean along with autorich are functions of the mixture control lever. The throttle is either open or closed. Open means more manifold pressure closed means less. Another function of the autorich setting or power enrichment valve is to add more fuel during high throttle settings. In this case the additional fuel helps with the cooling of the cylinder head. Likewise leaning will cause a rise in cylinder head temperatures. Again it is the lowering of manifold pressure that accounts for the lessened fuel consumption. Just lowering rpm,s which is accomplished by adding more pitch to the prop blades actually places more of a load on the powerplant. A good way to think of this is if you are in an auto with the throttle set in one position. If the car starts up an incline, as the powerplant is loaded the rpm,s will decrease because of the additional load but fuel consumption will actually rise . You need to close the throttle plate in order to conserve fuel.

- md_wild_weasel - 19.01.2009

OMG Confusedhock: how long do you actaully want your flights to last??? lol, 25% fuel in a p38 goes a long,long, long,long, long, long, way! heck 50 fuel and you could be flying all day! :lol:

- KC Jones - 19.01.2009

md_wild_weasel Wrote:OMG Confusedhock: how long do you actaully want your flights to last??? lol, 25% fuel in a p38 goes a long,long, long,long, long, long, way! heck 50 fuel and you could be flying all day! :lol:

A very interesting and in-depth discussion. I like it.

But I got to tell you, that last night one of our members exploded after the usual question of "what fuel loadout should we use for this mission ?"

The guy who made the mission shouted in some not so polite words something like "what the heck fuel load do you think the pilots in WWII took off with ?"

After a long silence it was agreed they took off with full tanks.

Maybe a vet of the war here or someone who knows one still living can confirm or tell differently.

But from now on we decided that's the way we would do it.

Carry on

- dihedral - 19.01.2009

md_wild_weasel Wrote:OMG Confusedhock: how long do you actaully want your flights to last??? lol, 25% fuel in a p38 goes a long,long, long,long, long, long, way! heck 50 fuel and you could be flying all day! :lol:

This just my point! You won't stay aloft that long! Even with full tanks, but no drop tanks, and bombs I flew a mission from Henderson field to Munda and me and the rest of my AI squadron all ran out of fuel and drowned about 50 miles from Henderson on the way back. The game runs the P38 at full rich all the time. It seems a pity now we have these great new maps like the Slot not to be able to fly historic long range missions.