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lbuchele
07-09-2008, 05:59 AM
I'm using CEM about a week ( after 8yrs playing), and enjoing very much the added workload ( I'm a sad person... http://forums.ubi.com/images/smilies/shady.gif)
So, have some questions:
1.Does you guys have found some real utility messing around with mixture controls, offline and online?
2.generally speaking, what´s the best altittude to change supercharger stages?

Uufflakke
07-09-2008, 06:41 AM
Maybe this copypaste of www.airwarfare.com (http://www.airwarfare.com) about using the Supercharger will help:

Supercharger or Turbocharger
Is a device that compresses the fuel/air mixture an engine inducts to be burned in the cylinders to produce power. As altitude increases the density of air decreases, the engine has less air to burn and in turn losses
power. If you go high enough with out a supercharger or turbocharger the engine may stop running or will not produce enough power to climb any higher. A supercharger will allow an engine to produce better power at higher altitudes. Some planes have a 2 stage supercharger or in other words gearing to run at different speeds. First stage, stage 1 is used at lower altitudes 0-3km's, second stage, stage 2 is used for higher altitudes 3km to the maximum attainable altitude. Different aircraft and there superchargers are geared differently. Therefore in some aircraft you may be able to switch from stage 1 to stage 2 at 2.5 km's while in others you will not have to switch to stage 2 until 3.5km's or 4km's. If you switch to stage 2 at low altitudes the supercharger will produce more pressure (boost) than the engine will be able to handle and will eventually ruin the engine.

Look at your manifold gage to check your supercharger pressure. Rule of thumb to use is if you switch to stage 2 and you do not experience an increase of power or rpm's go back to stage 1. If your at high altitude using stage 2 and dive on an enemy remember when you get to low alt you will need to switch to stage 1 or engine damage may result. Some aircraft do not have a supercharger or use a multi stage supercharger or have a turbocharger that needs no adjustment. You will need to bind a key to stage 1 and stage 2 to adjust stages in aircraft with this feature. To find out if your aircraft has an adjustable 2 stage supercharger press the key you bound to stage 1 or 2, if you do not see the selected stage displayed on the right hand side of your screen that aircraft does not offer adjustment.

Other info about CEM you can find in this link:
http://www.airwarfare.com/Sims/FB/fb_cem.htm

I think it will help you out...

lbuchele
07-09-2008, 08:31 AM
Thanks for remenber me this source, mate.
So, let me see if I understand: less pitch "grabs" more air, so if I'm climbing have to reduce pitch to 90-95% ?
If I reduce pitch diving , to spare engine of overevving , I also build up even more speed?
Best pitch to take off and landing?
Maybe now is a good moment to buy a throttle quadrant with pitch and mixture controls...
Bottom line it´s much more interesting flying with CEM enabled to me.

OMK_Hand
07-09-2008, 09:10 AM
A few pearls http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

"Aerobatics and manoeuvres should be performed with a high rpm setting in order that high power can be obtained by simply advancing the throttle lever"

- this often includes take off and landing.

"Supercharger ratio should be changed from M' (low) to S' (high) when the boost at full throttle has fallen by 2 to 5 lbs per square inch
The height at which this occurs varies with boost, rpm and airspeed."

"The engine gives less power in s' ratio. Use m' ratio for cruising whenever possible"

"The throttle should be opened fully above full throttle height."

Uufflakke
07-09-2008, 11:44 AM
Originally posted by lbuchele:
Thanks for remenber me this source, mate.
So, let me see if I understand: less pitch "grabs" more air, so if I'm climbing have to reduce pitch to 90-95% ?
If I reduce pitch diving , to spare engine of overevving , I also build up even more speed?
Best pitch to take off and landing?
Maybe now is a good moment to buy a throttle quadrant with pitch and mixture controls...
Bottom line it´s much more interesting flying with CEM enabled to me.

Prop pitch is a part I still don't understand very well, so many times I don't change it manually but leave it on automatic.
And what I've understand here on the forum is that the prop pitch of a Bf109 works in a different way than other planes (just to make it more complicated)
Anyway when I have some time I have to concentrate on prop pitch as well.
I discovered this site today with a lot more info about prop pitch, controlling rpm, etc.
http://people.ee.ethz.ch/~chapman/il2guide/cemguide/proppitch.htm (http://people.ee.ethz.ch/%7Echapman/il2guide/cemguide/proppitch.htm)

Ronbo3
07-09-2008, 12:28 PM
Best way to look at prop pitch in this sim only, is that it controls rpm. IE, 100% could be 3000 rpm, 75 2550 (as an example) the aircraft/engine combos have certain rpm limits for different things.

I read that site as well, and being an A&P mechanic, it confused me abit with the indepth info. http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

julian265
07-09-2008, 05:23 PM
With regard to supercharger settings - you have to use them a little differently in game, to real life.

Different engines have different optimum supercharger change altitudes. I use IL2 compare to find to find them - look for the altitude at which the speed line starts to increase again, this is when supercharger stages was changed.

Of course, you can test it easily. Pick an altitude and fly level. Try different supercharger stages without changing anything else, and the one that gets you the most speed is the right one. (it takes up to a minute for speed to stabilise after each change)

Regarding pitch - if you want the most power, leave it at 100%. (unless you're in the tempest or some 190s, which rev too high in boost in a steep dive) Most planes cope just fine whilst diving with 100% pitch.

If you fly using realistic settings and engine limits, you'll be at a disadvantage whether online or off.

WTE_Galway
07-09-2008, 05:26 PM
Originally posted by julian265:


Regarding pitch - if you want the most power, leave it at 100%. (unless you're in the tempest or some 190s, which rev too high in boost in a steep dive) Most planes cope just fine whilst diving with 100% pitch.

.

Just do not try that in a 109 either.

In a 109 set throttle to your desired ATA and then leave the throttle alone and use pitch to keep revs in the engines optimal power zone (varies with model) and ALWAYS reduce pitch on takeoff and when diving or you will throw a con rod from over-revs. 109 really needs pitch on a slider.

lbuchele
07-09-2008, 05:33 PM
But 109's has automatic pitch control in real life, isn't true?

Kettenhunde
07-09-2008, 07:15 PM
In RL, the faster you go, the co****r your pitch will become on a CSP. When it reaches full co**** then it will begin to drive the engine if speed continues to increase.

The slower you go, the finer the pitch. This is why full fine pitch is used for take offs and climbs. It's part of your GUMP check too.

Don't confuse RPM with pitch either. High RPM always delivers more power. Power and rpm are directly related in the physics. Another reason why it is used for times when we need maximum power.

With a CSP, it is very possible to be at maximum rpm and full co**** pitch at very high speeds. If our manifold pressure begins to rise then our propeller is driving the engine.

http://www.upscale.utoronto.ca/PVB/Harrison/EnginePower/EnginePower.html

Why won't the BBS let me say C-O-A-R-S-E?

All the best,

Crumpp

Kettenhunde
07-09-2008, 07:28 PM
But 109's has automatic pitch control in real life, isn't true?

AFAIK on the Bf-109E had a true pitch adjustable propeller and then only a few of them. I image that whenever the engine could be set up for CSP use it was done. The engine has to be plumbed for the governor and shaft is generally the conduit for the oil.

The VDM Hydraulic-Electric propellers used on the Bf-109E/F/G series and the FW-190 series act as any other CSP while in the normal operational mode. Normal mode uses a hydraulic governor driven from the engine oil. It is a typical CSP design.

In an emergency should the governor be damaged or the engine loses oil pressure, the propeller can be switched to an adjustable pitch propeller driven by electric motors.

Not all VDM propellers in early use where the hydra-electric propellers.

All the best,

Crumpp

WTE_Galway
07-09-2008, 08:12 PM
Originally posted by lbuchele:
But 109's has automatic pitch control in real life, isn't true?

Kettenhunde seems to know more about it then me, my info was early Emil's (BoB period) did not, but from Barbarossa onwards yes they all did.

However the reason people use manual pitch on a 109 in game is that you can get slightly more climb and a touch more speed in pursuit or when running away if you are good with manual pitch.

M_Gunz
07-10-2008, 12:09 AM
What CSP "pitch" (really is rpm % of maximum) gets the most speed depends on the speed and
power of the engine. You can find the truth of that in high speed dives and in flight at
less than maximum power -- see if 70% power is faster at 100% rpm than closer to 70% rpm.
The less power you use, the more that 100% rpm will act as a brake/speed control in CSP
planes. In CSP dives much over level speed max it is also faster in game with lower rpm.

Running less rpm will let your engine run cooler and use less fuel.

DmdSeeker
07-10-2008, 03:00 AM
Mixture:

There's really only to scenario's you'll need to use it.

On the deck (under 100 feet) mixture 120% can give a very small power boost (which can help a bit getting off a CV).

At higher alts in most russian planes and some german buffs you'll need to lean the mixture off (mix =80%). The first symptom is you'll be leaving smoke trails, and next you start losing power.

In the rare times you really, really need to squeeze every last drop of range out of your plane to get home, then prop pitch and power at 50 % and mix at 80% will get you a long way.

M_Gunz
07-10-2008, 06:02 AM
Try not fining the mix in a P-40B at above mid-alt some time.
That's not the only non-Russian bird you have to futz with the mix to get right.