Rpms and counterintuition

[Sublime]

Bear with me.

Pmease spare me mafs..

Ok so its said high rpmsow accelerstion etc but youll go fsster long term lowering them.

Eg the p51 if you lower to 83% ir 2700 rpm iirc itll.attain morr speed.

I know this changes on a lot of factors.

What rules of thumb do you gjys use?  What planes is this really important on whilst others not so much?  Even flying at 30k feet my.p47 is a dog. What am I doing wrong.

Particularly interested in p40 vs p38.  P40 allisons stay at 73% 80% for emergency. P38s staybat 83% unless emergency. Same engine.. but jist upgrades?

Also interested in - P47 - intercoolers. What do  i do? I leave em at 50%. I dont understand their function.. 

I16. I assume i opem inlets totally?

Interested in best p51 performance.

Otherplanes sure. But witout crazy math and whilst telling me x y settings Id like to know

When to lower rpms.  I get it has ti do with catching air bla bla.  Dont care.  I do care abkut when I need to throttle back or lower rpms to gain speed vs not

Id also like to know on fuel - does it add speed or any adcantage going full richbwith planes witbout throttle boost? Dersheriff surprised me and taught me the La5F wont overheat if you keep the mix at 80.to 100%

Answers guys please

Yes I know there are some typos ONCE PLEASE LET IT SLIDE.

thanks

[69th_Mobile_BBQ]

P51 - I usually leave the RPM at 2700 unless I need more climb or level acceleration.  

 

P40 and P38 Allisons are very similar, but there are different other parts attached to the engine block.  The P38 is much improved.   I find that for level flight, I get good speed from the P38 by putting the RPM in the "green zone" of the RPM gauge. (~2300 RPM) 

 

I16 - I usually leave the inlets open.  They do act as additional armor when closed for attacking planes that can shoot back with gunners or when attacking ground guns.  I close them for that, but only a short time as the engine actually can overheat.  

 

From what I understand of the P47 - I don't know if it's modelled in-game - having the engine temperatures too high or low can cause a lot of horsepower to be lost.  I'm not sure which parts control what temperature in the engine system, but the temperature gauges should all have "green zones" to show the right temperatures.

[ShamrockOneFive]

22 minutes ago, Sublime said:

Bear with me.

Pmease spare me mafs..

Ok so its said high rpmsow accelerstion etc but youll go fsster long term lowering them.

Eg the p51 if you lower to 83% ir 2700 rpm iirc itll.attain morr speed.

I know this changes on a lot of factors.

What rules of thumb do you gjys use?  What planes is this really important on whilst others not so much?  Even flying at 30k feet my.p47 is a dog. What am I doing wrong.

Particularly interested in p40 vs p38.  P40 allisons stay at 73% 80% for emergency. P38s staybat 83% unless emergency. Same engine.. but jist upgrades?

Also interested in - P47 - intercoolers. What do  i do? I leave em at 50%. I dont understand their function.. 

I16. I assume i opem inlets totally?

Interested in best p51 performance.

Otherplanes sure. But witout crazy math and whilst telling me x y settings Id like to know

When to lower rpms.  I get it has ti do with catching air bla bla.  Dont care.  I do care abkut when I need to throttle back or lower rpms to gain speed vs not

Id also like to know on fuel - does it add speed or any adcantage going full richbwith planes witbout throttle boost? Dersheriff surprised me and taught me the La5F wont overheat if you keep the mix at 80.to 100%

Answers guys please

 

With American aircraft you nearly always have manual control over mixture, RPM and manifold pressure. That is of course fuel mix, prop pitch and throttle in the in-game technochat respectively.

 

Most of the time with American aircraft I focus on RPM and manifold pressure first. I then look on the fuel mixture lever and find the percentage points where the aircraft is in 'auto lean' for cruise and 'auto rich' for combat. I worry less about mixture although if you feel your RPM's are a little low I'll usually play with mixture to see if I can get the RPM's up. There's usually a sweet spot for any given altitude but it is constantly changing.

 

For things like radiators I work with them on an as needed basis using the oil and radiator temperatures to figure out optimal settings.

 

As for lowering the RPM to get speed, this is usually in a high speed dash where the airplane is traveling quickly. There's a peak efficiency of the propeller that once exceeded starts to cause drag rather than increase in thrust. Best way to figure this out is watch the speed indicator and see if reducing pitch by say 5-10% nets you a few extra miles per hour on the speed indicator. A lot of this can be trial and error because every rule of thumb usually has a break point where it stops being relevant and you have to think about something else.

 

I've been flying IL-2: Great Battles since 2013... I'm still learning new things.

 

22 minutes ago, Sublime said:

Yes I know there are some typos ONCE PLEASE LET IT SLIDE.

thanks

 

I'd like to try and help you here Sublime. It's easier to communicate and to help you when we know what you're saying. The one above I was able to figure out but it isn't easy. Far from being critical I want to encourage you to keep working on writing. It will make it easier for you ultimately. There are tools available to help with most web browsers such as Chrome and Firefox having built in spell checking. Make full use of them - I certainly do! Another tool you may want to consider is something called Grammarly (https://www.grammarly.com/). I don't use it regularly but I have before and it can be helpful solving gramatical errors.

 

Some say it doesn't matter but I very much take the opposite view and just like flying and learning aviation engine technology, this is something that you practice over time. It doesn't happen over night.

 

Good luck!

[56RAF_Stickz]

43 minutes ago, Sublime said:

Also interested in - P47 - intercoolers. What do  i do? I leave em at 50%. I dont understand their function.. 

intercoolers control the carb temps (gauge is on engine panel above oil temp indicator. If you get it too cold it can stop the engine - although dont know at what point. 50% default setting will do 90% of the time, if my indicator starts to drop below 0 I do close them up. It maybe why some are having the engine die at altitude as not had it happen too me for a long time.

P47 is only plane that at >=30k that you can dive 5000feet and zoom climb back to where you started and still have manoeuvre speed - but dont do anything sudden .

It would be handy if you grouped sentances about a particular plane together instead of spreading them round (similar to shamrocks comment re being easier to communicate and answer in one go).

Happy easter to you and keep safe over the pond

[Lusekofte]

On radials mixture actually play a huge part in cooling down the engine. And it is simulated in this game. Try to climb to 17 000 feet with a A 20 with different mixture settings and you will see the difference
At level flight rpm will give you great speed at lower end of parameter but slow acceleration. 
you will see this best at altitude. If you pitch down the RPM the manifiol will go down. 
Flying free flight offline getting accustom to engine settings is a good thing. Or spend time in a bomber climbing up to 6 K. It alsogive you time to fiddle and understanding engine management. 
If you can do the P 47 up to 18 000 with its boost and get it right and as fast as it go. You can fly anything. Have not yet flown it after latest patch. Hope it turned out well. By far my absolute favorite plane

Edited April 12, 2020 by 216th_LuseKofte

[41Sqn_Skipper]

18 minutes ago, ShamrockOneFive said:

 

As for lowering the RPM to get speed, this is usually in a high speed dash where the airplane is traveling quickly. There's a peak efficiency of the propeller that once exceeded starts to cause drag rather than increase in thrust. Best way to figure this out is watch the speed indicator and see if reducing pitch by say 5-10% nets you a few extra miles per hour on the speed indicator. A lot of this can be trial and error because every rule of thumb usually has a break point where it stops being relevant and you have to think about something else

 

That doesn't make sense: if the enigne is running at 3000 rpm the propeller is always spinning at the same speed. Obviously your propeller will have a reduction gear to have highest efficiency at 3000 engine-rpm.

 

If you dive so fast that your CSP is unable to coarse the pitch any further (because the degrees of prop pitch are limited to a certain degree) your RPM will raise, but moving RPM lever backward will not reduce it as the csp is already at the limit. In this case you need to throttle back and leave the dive. This really is only an issue for pre-war/early war aircraft, e.g. early Spitfire Mk. I with DH propeller had only 20° pitch (originally a propeller with only 2 positions), while the Rotol CSP had already 35° pitch.

 

There is no point in reducing rpm to get faster: your engine will produce less horse-power and thus you will slow down.

[ShamrockOneFive]

40 minutes ago, 41Sqn_Banks said:

 

That doesn't make sense: if the enigne is running at 3000 rpm the propeller is always spinning at the same speed. Obviously your propeller will have a reduction gear to have highest efficiency at 3000 engine-rpm.

 

If you dive so fast that your CSP is unable to coarse the pitch any further (because the degrees of prop pitch are limited to a certain degree) your RPM will raise, but moving RPM lever backward will not reduce it as the csp is already at the limit. In this case you need to throttle back and leave the dive. This really is only an issue for pre-war/early war aircraft, e.g. early Spitfire Mk. I with DH propeller had only 20° pitch (originally a propeller with only 2 positions), while the Rotol CSP had already 35° pitch.

 

There is no point in reducing rpm to get faster: your engine will produce less horse-power and thus you will slow down.

 

I encourage you to fly at high speed at low altitude in a Yak-1B. Reducing the pitch percentage (lowering the RPM) will put the propeller in a more efficient and less draggy state and you'll see the speed increase. I've shot a bunch of 109's who thought they were safe at low altitudes doing this. I'm sure this is relevant to other aircraft too but this is the one I have the most vivid memories of seeing an immediate increase in speed. It's not a lot but in a high speed low altitude dash every extra kilometer an hour counts.

[41Sqn_Skipper]

I just tested Spitfire V and MIG-3, in both my speed dropped when moving the RPM lever from 100% to 80%. Just as I expected. Then I tested the  Yak 1 series 69 and was surprised to achieve higher speed when lower RPM (at 2550 RPM instead of the 2700 RPM). So how I that even possible? I looked up the aircraft specification for Yak1 and Yak1B:

 

 

Engine:

Model: M-105PF

Maximum power in Nominal mode (2550 RPM) at sea level: 1240 HP

Maximum power in Nominal mode (2700 RPM) at sea level: 1210 HP

Maximum power in Nominal mode (2700 RPM) at 800 m: 1260 HP

Maximum power in Nominal mode (2700 RPM) at 2700 m: 1200 HP

 

So in these particular aircrafts, there is more horse-power at lower RPM at sea level. So obviously, you will go fast at the lower RPM setting. But this is a really special case that doesn't apply universally to other aircraft. 

 

This behavior can't be caused by the propeller though, I'd guess it's caused by the supercharger reduction gear: Higher RPM is needed above FTH to spin the supercharger faster to create enough boost, but at that higher RPM the engine already produced less HP. Using a different reduction gear would allow to create the same boost above FTH even at the lower RPM, but then there would be more HP "wasted" to spin the supercharger at a faster speed below FTH. So one could say that the engine is optimized for more HP below FTH but at the cost of lower efficiency above FTH.

 

 

[Sublime]

Hi guys thanks for all the awesome advice.

I really appreciate it.

Some I knew for example p41 2700 rpm is my standard. When is 3000 good? Acceleration? Not stalling in a low energy fight? At what height or speed does 2700 produce faster speed? Or is this a myth

The advice going by technochat (max realism you still will get overheat msgs plus your plane 'steams' and fiddling works most of teh time.

However Ive noticed flying according to designers intent has made for example my fw190 experience MUCH more effective 

The p47 idk what Im doing shes a dog at any alt.

On the grammar.. my friend I dont think you understand. I juggle so little time. And I could type mostly properly - I wont lie I cant define the technical aspects of advanced written english.  I just am lazy frankly about it.

I do understand that posting while intoxicated pwi is the cause of most my posts hence me staying away inebriated lol.

Otherwise im sorry but for example this is atrocious english technically but can you seriously suggest you dont know what Im talkin about?

Please dont be insulted. I have a 9 year old son and Im the only parent left in his life.  He has lotsa other familial support (grandmas) though and hes fine. That work and my little time playing a game trump for me what eerily seems like homework my friend.

 

Edited April 12, 2020 by Sublime

[CountZero]

 

[MasserME262]

Everyone worrying about speed and here I am being chased by AI everytime even if I'm in a F4 going at 550 kmh against a Rata lol.

[ShamrockOneFive]

30 minutes ago, Sublime said:

Hi guys thanks for all the awesome advice.

I really appreciate it.

Some I knew for example p41 2700 rpm is my standard. When is 3000 good? Acceleration? Not stalling in a low energy fight? At what height or speed does 2700 produce faster speed? Or is this a myth

The advice going by technochat (max realism you still will get overheat msgs plus your plane 'steams' and fiddling works most of teh time.

However Ive noticed flying according to designers intent has made for example my fw190 experience MUCH more effective 

The p47 idk what Im doing shes a dog at any alt.

 

With the P-47 you'll want the max RPM available. The 47 is a very heavy aircraft with a very big engine attached to it. It works but it requires a lot of careful discipline and frankly I have a much easier time of the other aircraft being used as a fighter. It's very good up at high altitude and I find that when I link the turbo, rpm, and throttle controls together I have an altogether easier time even if its not the method to extract the absolute most from it.

 

Sherrif's Sim Shack has the best explanation of how to get the most out of the P-47's engine.

 

 

No matter what you do, however, you're not going to make the P-47 a nimble fighter. It just wasn't that. But put a squadrons worth of them cruising at 25,000-30,000 feet and you can quickly see how they made a significant mark on the European air war.

 

30 minutes ago, Sublime said:

On the grammar.. my friend I dont think you understand. I juggle so little time. And I could type mostly properly - I wont lie I cant define the technical aspects of advanced written english.  I just am lazy frankly about it.

I do understand that posting while intoxicated pwi is the cause of most my posts hence me staying away inebriated lol.

Otherwise im sorry but for example this is atrocious english technically but can you seriously suggest you dont know what Im talkin about?

Please dont be insulted. I have a 9 year old son and Im the only parent left in his life.  He has lotsa other familial support (grandmas) though and hes fine. That work and my little time playing a game trump for me what eerily seems like homework my friend.

 

 

About 80% of the time I can decipher what you're saying but there are so many jumbled words that it makes it about four times as difficult to parse through. Most of the time I will pass by... I want to help but you make it hard on us

 

IMHO, I don't exactly buy the argument that it's quicker to type that way. Like I said, there are tools like spellcheckers and Grammarly that can help you make a few quick corrections extremely quickly. To write as much as I do requires me to write quickly and not spend tons of time doing it. This is not to admonish you or any difficult circumstances that you're facing. I'm here, like you, because I love flying and flight sims and if I can help you (or you can help me) then all the better. Give us an extra 5% on grammar and I think it'll be that much easier to help!

[Sublime]

Hey im just telling u wat works for me.

As for the p47 ok interesting. I had un interlocked my rpm and throttle but not turbo.

Btw can you guys give me advice on a good gaming desktop rig or laptop around 600 dolllar range? Also tempted to buy the LW copy joy.

Would I be better with hotas?

Finally.. VR. Everyone who does it is like... religious about it.  I wanna take the plunge but can a 600 dollar desktop support il2 and dcs vr?

[Lusekofte]

1 hour ago, 41Sqn_Banks said:

just tested Spitfire V and MIG-3, in both my speed dropped when moving the RPM lever from 100% to 80%.

You are not paying attention to how proppellers work. The reason props reduse rpm is kind of like a gear in a car.  Pitch work different on different propeller system. 
If you take. Yak or a JU 88 fir a spin you will find that if you pitch down % as you say it. Propeller will grab more air and manifoil pressure will decrease. Some planes have other system on their propellers like constant speed but the reason you want to change angle on your prop is that you can accellerate and climb better. And you can fly faster level flight without too much manifoil pressure. 

[Sublime]

1 hour ago, 216th_LuseKofte said:

You are not paying attention to how proppellers work. The reason props reduse rpm is kind of like a gear in a car.  Pitch work different on different propeller system. 
If you take. Yak or a JU 88 fir a spin you will find that if you pitch down % as you say it. Propeller will grab more air and manifoil pressure will decrease. Some planes have other system on their propellers like constant speed but the reason you want to change angle on your prop is that you can accellerate and climb better. And you can fly faster level flight without too much manifoil pressure. 

Ok i like your explanation

Now imagine we are driving a stick

The rpms staet getting high so i go to switch to a higher gear they drop and start raising as i apply throttle

Whats my sign to drop my throttle in il2? Like when for example on a p51 how do i know - from istruments - that Im not going to gain anymore out if 3000 rpm and 2700 will now improve speed?

[Lusekofte]

If the angle of the prop is set to a high % you are going to accelllerate until reach top speed of that 1 gear you chosen. In order to get more speed you need to make your proppeller more efficient by letting it grab more air so you "put it on lesser % to do so. In some planes that demand more power of the engine, up high where the air is thinner this will make a huge difference and you will see the less % you have on your pitch the less ATA you get on the manifoil pressure. Less % means grabbing more air or higher gear on transmission on a car. You will accellerate slower but being able to fly faster. This happen at low altitude also , when finnishing with fast accelleration, you need to get a more efficient angle of the props in order to get it faster.

There are different propeller systems, and I believe Spitfire have slightly different than yak. But the theory is the same. You need to ask more technical people about how different propeller system work , my English is simply too bad. You got constant speed propellers and other things. But this is why propellers evolve from what you get in a ww1 plane to what you get in ww2

[41Sqn_Skipper]

30 minutes ago, Sublime said:

Ok i like your explanation

Now imagine we are driving a stick

The rpms staet getting high so i go to switch to a higher gear they drop and start raising as i apply throttle

Whats my sign to drop my throttle in il2? Like when for example on a p51 how do i know - from istruments - that Im not going to gain anymore out if 3000 rpm and 2700 will now improve speed?

 

I really hate the car gear analogy, because it can't be applied to an aircraft with a CSP. And almost all aircraft in this sim have a CSP. The car gear analogy causes exactly the thinking: "But when do I need to switch to higher gear?" The answer is: You don't, because the CSP is already switching for you to the higher gear. 

 

If you wan't to accelerate the fastest in your car, you need to switch to the higher gear as late as possible, right before you overspeeding the engine. So in other words you try to keep the engine at the highest possible RPM all the time, because this will where it actually creates the highest HP.

 

In an aicraft with a CSP this is actually pretty easy: Just select the highest possible RPM with the RPM lever and the CSP will manage propeller pitch to keep the engine running at the desired RPM all the time, thus the engine produces the highest possible HP all the time.

 

Highest HP means highest possible acceleration force, which means higher airspeed.

 

9 minutes ago, 216th_LuseKofte said:

If the angle of the prop is set to a high % you are going to accelllerate until reach top speed of that 1 gear you chosen. In order to get more speed you need to make your proppeller more efficient by letting it grab more air so you "put it on lesser % to do so. In some planes that demand more power of the engine, up high where the air is thinner this will make a huge difference and you will see the less % you have on your pitch the less ATA you get on the manifoil pressure. Less % means grabbing more air or higher gear on transmission on a car. You will accellerate slower but being able to fly faster. This happen at low altitude also , when finnishing with fast accelleration, you need to get a more efficient angle of the props in order to get it faster.

There are different propeller systems, and I believe Spitfire have slightly different than yak. But the theory is the same. You need to ask more technical people about how different propeller system work , my English is simply too bad. You got constant speed propellers and other things. But this is why propellers evolve from what you get in a ww1 plane to what you get in ww2

 

What you describe is only important to understand for a propeller with manual pitch control. And there is no aeroplane in this sim that has a manual pitch propeller. They all have a CSP* or a fixed pitch (Ju52 and Po2). The CSP does exactly what you describe automatically so that the pilot doesn't need to care about it. 

 

 

* German fighters basically have a link between the CSP and the throttle so that the selected RPM is automatically adjusted depending on the throttle setting, but in the end the propeller pitch is again automatically regulated like with a CSP.

Edited April 12, 2020 by 41Sqn_Banks

[Lusekofte]

1 hour ago, 41Sqn_Banks said:

really hate the car gear analogy, because it can't be applied to an aircraft with a CSP

Like I said it is an easy  way to talk about pitch. And you fly too much fighters. I fly planes that do not have CPS. And we get a few of those. You should try them
Anyway the analogy come from bad English But it is interesting you are saying the angle of the propeller has nothing to do with rpm. 
I tried merely to tell about what a propeller do. Childish yes, and I claim no knowledge of how a constant speed propeller work. But you say we aint got planes with manual pitch then that is new to me. 
it is very simple to see the difference on how the P 38 act compared to JU 88 PE 2 I 16 

 

Edited April 12, 2020 by 216th_LuseKofte

[216th_Jordan]

3 hours ago, 41Sqn_Banks said:

Highest HP means highest possible acceleration force, which means higher airspeed.

 

In general this would be true, but prop characteristics are different and do have effects. But the effects should usually be far smaller compared to the loss in HP that is brought by reducing RPM. This only really makes sense for engines with (larger) diminishing torque at the end of the RPM spectrum.

[The_Grim_1]

The way I fly in combat is boost on, throttle Max and RPM 2550ish and coolers under 40%. So everything maxed except for RPM. That configuration gives me about 20-30 min combat power and highest speed. It seems the timer is heavily influenced by RPM. Anyway after much testing you'll find if you autopilot for level flight at 3000ft the p47 is faster at 2550 RPM then 2700. Seriously give it a shot. 

 

At higher alt where the supercharger is about maxed then your MP is limited by the RPM and 2700 has a benefit but as long as you still have full MP pressure 2550ish RPM seems best.

 

The p-47 is a very different plane than everything else in the game. I strongly recommend you try Jade monkey's high altitude p-47 intercept mission. At first I had a hard time with it because the plane was too slow after a couple of maneuvers. That mission really makes you focus on energy conservation and an engine management. In order to be successful you have to learn to fly extremely differently. as of right now I can still attack the bombers without a problem but I'm hopeless against the k-4s still, they can't catch me but I can't turn with them when we cross paths without loosing all my speed.

Edited April 13, 2020 by The_Grim_1
fixed some numbers that 41sqn_banks pointed out

[41Sqn_Skipper]

2 hours ago, The_Grim_1 said:

The way I fly in combat is boost on, throttle Max and RPM 2700ish and coolers under 40%. So everything maxed except for RPM. That configuration gives me about 20-30 min combat power and highest speed. It seems the timer is heavily influenced by RPM. Anyway after much testing you'll find if you autopilot for level flight at 3000ft the p47 is faster at 2700 RPM then 3000. Seriously give it a shot. 

 

At higher alt where the supercharger is about maxed then your MP is limited by the RPM and 3000 has a benefit but as long as you still have full MP pressure 2700ish RPM seems best.

 

I'm a bit confused. Are you talking about the Turbo RPM? Because the engine RPM is limited to max 2700 in P-47.

6 hours ago, 216th_Jordan said:

 

In general this would be true, but prop characteristics are different and do have effects. But the effects should usually be far smaller compared to the loss in HP that is brought by reducing RPM. This only really makes sense for engines with (larger) diminishing torque at the end of the RPM spectrum.

 

Is a variable propeller efficiency even simulated? I'd assume its a constant value, finding out that one would have been hard enough for all the props. 

[216th_Jordan]

4 hours ago, 41Sqn_Banks said:

Is a variable propeller efficiency even simulated? I'd assume its a constant value, finding out that one would have been hard enough for all the props. 

 

AFAIK yes. For example Yak-1b uses an improved prop over the Yak-1 ser. 69 while the governor stayed the same, the results are noticable. 

Edited April 13, 2020 by 216th_Jordan

[The_Grim_1]

5 hours ago, 41Sqn_Banks said:

 

I'm a bit confused. Are you talking about the Turbo RPM? Because the engine RPM is limited to max 2700 in P-47.

 

Is a variable propeller efficiency even simulated? I'd assume its a constant value, finding out that one would have been hard enough for all the props. 

engine RPM Sorry, i was recalling the numbers from memory and misspoke. i should have said 2550 rpm and 2700, but my point still stands that the the top speed is faster with a lower RPM then maxed out. i'm going to edit the post as not to confuse anyone else. thanks for point that out.

[41Sqn_Skipper]

55 minutes ago, The_Grim_1 said:

engine RPM Sorry, i was recalling the numbers from memory and misspoke. i should have said 2550 rpm and 2700, but my point still stands that the the top speed is faster with a lower RPM then maxed out. i'm going to edit the post as not to confuse anyone else. thanks for point that out.

 

I just tested P-47. Kuban Summer, altitude 300m, Throttle 100% (no boost), turbo RPM 0%, oil radiator 100%, cowl flaps 0%. Running "level autopilot" and 8x time compression to notice the low acceleration changes.

 

With 2700 RPM, speed is about 285 MPH

 

Dropping RPM to 2500, speed drops to about 282 MPH

 

Increasing back to 2700 RPM, speed increases again to 285 MPH

 

 

Edited April 13, 2020 by 41Sqn_Banks

[The_Grim_1]

ok so i just did some testing and i looks like what i said about the boost may have been a bug that was fixed. before you could run the rpm at 2500 with boost and only use combat power? that does not seem to be the case any longer. strange. anywhy here are some tested i did. i tested at both 3,000M and 300M.

 

2500 RPM gave faster top speeds then 2700 RPM with the added bonus of twice the combat power time 30 vs. 15 minutes. i find it strange you had the turbo at 0%

 

Setup:

Kuban Summer

outlet shutters 0%,

inlet 40%

radiators 30%

700L of fuel (with unlimited fuel on to stop change in weight)

*all tests used full throttle and full Supercharger

 

----*3,000m Testing*----

 

3,000M no boost

MP=52' , RPM = 2500

Top speed = 297 MPH with 30 minutes combat power

 

MP=54" , RPM = 2700

Top speed = 289 MPH with 15 minutes combat power

 

3,000m Boost

MP=max , rpm = 2500

top speed = 322 MPH with 5 minutes

 

MP = max, RPM = 2700

Top speed = 322 MPH with 5 minutes

 

---*300m testing*---

 

300M no boost

MP=52' , RPM = 2500

Top speed = 310 MPH with 30 minutes combat power

 

MP=54" , RPM = 2700

Top speed = 307 MPH with 15 minutes combat power

 

300m Boost

MP=max , rpm = 2500

top speed = 342 MPH with 5 minutes

 

MP = max, RPM = 2700

Top speed = 339 MPH with 5 minutes

 

Edited April 13, 2020 by The_Grim_1

[Voyager]

12 hours ago, The_Grim_1 said:

[...]

 

The p-47 is a very different plane than everything else in the game. I strongly recommend you try Jade monkey's high altitude p-47 intercept mission. At first I had a hard time with it because the plane was too slow after a couple of maneuvers. That mission really makes you focus on energy conservation and an engine management. In order to be successful you have to learn to fly extremely differently. as of right now I can still attack the bombers without a problem but I'm hopeless against the k-4s still, they can't catch me but I can't turn with them when we cross paths without loosing all my speed.

 

Interesting. Where would one do a that mission? I haven't generally done scripted missions, so not terribly familiar with which ones are available or how to find them. 

[The_Grim_1]

your in for a real treat!  for user created missions and careers look under  Scripted Campaigns and Single player Missions

for Jade_Monkey's awesome missions that i highly recommend click here and download to dropbox. Keep checking periodically as he keeps adding more missions. 

you'll want to extract the folder you download and paste the folder into : IL-2 Sturmovik Battle of Stalingrad\data\Missions folder

 

if there is a mission you like you can open it in the editor found in the IL-2 Sturmovik Battle of Stalingrad\bin folder and change the player aircraft to whatever you like and then re-save with a new file name. for instance i have the p-47 high altitude mission re-saved with the p-51. then i made another with all the He-111 swapped to b25 and the player aircraft a 262 or dora.

Edited April 13, 2020 by The_Grim_1

[Sublime]

On 4/12/2020 at 3:32 PM, 41Sqn_Banks said:

 

I really hate the car gear analogy, because it can't be applied to an aircraft with a CSP. And almost all aircraft in this sim have a CSP. The car gear analogy causes exactly the thinking: "But when do I need to switch to higher gear?" The answer is: You don't, because the CSP is already switching for you to the higher gear. 

 

If you wan't to accelerate the fastest in your car, you need to switch to the higher gear as late as possible, right before you overspeeding the engine. So in other words you try to keep the engine at the highest possible RPM all the time, because this will where it actually creates the highest HP.

 

In an aicraft with a CSP this is actually pretty easy: Just select the highest possible RPM with the RPM lever and the CSP will manage propeller pitch to keep the engine running at the desired RPM all the time, thus the engine produces the highest possible HP all the time.

 

Highest HP means highest possible acceleration force, which means higher airspeed.

 

 

What you describe is only important to understand for a propeller with manual pitch control. And there is no aeroplane in this sim that has a manual pitch propeller. They all have a CSP* or a fixed pitch (Ju52 and Po2). The CSP does exactly what you describe automatically so that the pilot doesn't need to care about it. 

 

q

* German fighters basically have a link between the CSP and the throttle so that the selected RPM is automatically adjusted depending on the throttle setting, but in the end the propeller pitch is again automatically regulated like with a CSP.

Im sure the analogt has you banging ur beas on a wall like quoea answwrs claiminf the vvs drew gunsights on their planes

Friend unserstand. Be was tryng to help me.

Im not full retard but close witb math physics enginea.

If the car analgy was bad fair nuff but i need ya to explain in similar terms.  Ans believe me CSP etc. No effn idea what youre on about.

Im at work hidinf postinf frm.my boss hence typos. Im a single parent ans poor.  I dont habe time to learn the physics and i know full well some here are smaet enuff to explain this to tarzan (me tarzan)

So pls if the infos bas step in. But ifnits just to sneer at the simplistic ezpanations im a simple man and that doesnt help

22 hours ago, Voyager said:

 

Interesting. Where would one do a that mission? I haven't generally done scripted missions, so not terribly familiar with which ones are available or how to find them. 

Hes right theyre all good missions

Nothing beats pwgc

Ghe hi alt mission i still cant make the p47 do much besudes act like a pig

On 4/12/2020 at 5:01 PM, 216th_LuseKofte said:

Like I said it is an easy  way to talk about pitch. And you fly too much fighters. I fly planes that do not have CPS. And we get a few of those. You should try them
Anyway the analogy come from bad English But it is interesting you are saying the angle of the propeller has nothing to do with rpm. 
I tried merely to tell about what a propeller do. Childish yes, and I claim no knowledge of how a constant speed propeller work. But you say we aint got planes with manual pitch then that is new to me. 
it is very simple to see the difference on how the P 38 act compared to JU 88 PE 2 I 16 

 

Yeah i was gonna say i thot some german bombers had diff pitch

[41Sqn_Skipper]

If you want to use an analogy, then a CSP is similar to automatic gearbox in a car. With the RPM lever you can select different modes:

• 100% RPM would be the Sport mode 
• ~80% RPM would be the regular Drive mode
• ~60% RPM would be the Economic mode

The exact percentages will vary depending on the engine, so you need to read the manual (which you can find at the following link):

 

 

 

[Lusekofte]

I would advise not to use tech chat and start looking at instruments. 
logic on how it works will follow swiftly. 
This % thinking will make the logic hard to get. 
before taking off read the specifics and follow them. 
If you want to take it to the limits, read the specifics and add a little more. Look at the watch and instrument and see how it goes. 
use techchat in the beginning as a guidance. 
very soon you will know how that plane works in this game, not its historical limits, but this games limits. And that is all you need to think of. I found P 39 p 40 and 38 to take a tad more in some parameters than tech chat and specifics say

Edited April 14, 2020 by 216th_LuseKofte

[Gambit21]

The car/gear analogy is spot-on for the most part. It allowed me to instantly grasp throttle vs RPM when I was confused on the subject back when. As soon as someone said “think of it like gas pedal and shifter I was off and running in the Yak.

 

German planes of course requiring no such grasp is many cases. 

[Lusekofte]

3 minutes ago, Gambit21 said:

 

The car/gear analogy is spot-on for the most part. It allowed me to instantly grasp throttle vs RPM when I was confused on the subject back when.

 

Yes thanks. That was what I aimed for. When someone ask what pitch does. You simply do not start with CPS and other types of propeller hub types. They try to make sense of it and frankly I do not know any better way to explain it 

[41Sqn_Skipper]

35 minutes ago, Gambit21 said:

The car/gear analogy is spot-on for the most part. It allowed me to instantly grasp throttle vs RPM when I was confused on the subject back when. As soon as someone said “think of it like gas pedal and shifter I was off and running in the Yak.

 

In a car you need to switch to a higher gear as your speed increases and switch to a lower gear when your speed decreases. Why you do that? To keep the RPM at a save and efficient range.

 

In an aeroplane with manual pitch control you do exactly the same thing: If speed inceases you need to set a higher pitch angle and if your speed decreases you need to set a finer pitch angle. Again, to keep the RPM at a save and efficient range.

 

Now with a CSP the constant speed unit changes the propeller pitch automatically to keep the RPM at the selected level. So all you need to do is use the RPM lever to select the RPM that you want and from now one there is no need to change the RPM level position even when your speed inceases or decreases.*

 

So if you tell someone who doesn't understand how a CSP works: "RPM level = gear shiftlever" this implies that the pilot needs to change the position of the RPM lever when speed increases or decreases.

And doing so unneccessary, will decrease your performance and may damage the engine due high load (not simulated I assume). That's why it is a misleading analogy. 

 

 

 

 

* You move the RPM lever to reduce or increase the selected RPM. You reduce RPM to reduce engine wear, save fuel and avoid overheating. You increase RPM to have more acceleration to fly faster, climb higher and maneouvre. And that's it ...

[The_Grim_1]

if we're going to use a car analogy i think it makes more sense to think of it as a manual car stuck in whatever gear lets say 3rd... and have the gas peddle stuck in one place. the pitch controls how much load is on the engine because it controls how much air it grabs and shoves back like a corkscrew. so back to our car the pitch/load is more like changing the level of the ground up or down hill. if you go up a hill the load is increased i.e. lower pitch grabs more air and slows the rpm (prop). if you go downhill load on the engine is decreased and the rpm(prop) increases. but if you go too fast the rpm will blow your motor so you change the pitch to put more load on the engine so as a safety the road curves up whenever you get near redline(the pitch angle/rpm limit you set in game).

 

i hope that makes some sense but that how i think of it... changing gears is very bad analogy

Edited April 15, 2020 by The_Grim_1

[Gambit21]

33 minutes ago, The_Grim_1 said:

.. changing gears is very bad analogy

 

No it isn't.

Like I said above I grasped how to operate the Yak immediately after someone gave me the analogy.

My brain makes the adjustment considering the CSP as well, though maybe not everyone makes that jump so easily.

[The_Grim_1]

41 minutes ago, Gambit21 said:

 

No it isn't.

Like I said above I grasped how to operate the Yak immediately after someone gave me the analogy.

My brain makes the adjustment considering the CSP as well, though maybe not everyone makes that jump so easily.

To each there own. It works for me because pitch/RPM on a CSP is putting load on the motor,  it's exactly what's happening. Gear shifting happens at altitude and confuses some people in that analogy. It's great you also get it but this is how I understood it and if it helps even one person all the better.

Edited April 15, 2020 by The_Grim_1

[Mollotin]

7 hours ago, 41Sqn_Banks said:

 

In a car you need to switch to a higher gear as your speed increases and switch to a lower gear when your speed decreases. Why you do that? To keep the RPM at a save and efficient range.

 

In an aeroplane with manual pitch control you do exactly the same thing: If speed inceases you need to set a higher pitch angle and if your speed decreases you need to set a finer pitch angle. Again, to keep the RPM at a save and efficient range.

 

Now with a CSP the constant speed unit changes the propeller pitch automatically to keep the RPM at the selected level. So all you need to do is use the RPM lever to select the RPM that you want and from now one there is no need to change the RPM level position even when your speed inceases or decreases.*

 

So if you tell someone who doesn't understand how a CSP works: "RPM level = gear shiftlever" this implies that the pilot needs to change the position of the RPM lever when speed increases or decreases.

And doing so unneccessary, will decrease your performance and may damage the engine due high load (not simulated I assume). That's why it is a misleading analogy. 

 

 

 

 

* You move the RPM lever to reduce or increase the selected RPM. You reduce RPM to reduce engine wear, save fuel and avoid overheating. You increase RPM to have more acceleration to fly faster, climb higher and maneouvre. And that's it ...

 

this is correct.

 

constant speed prop does not behave like a manual car transmission.

 

 

 

 

 

 

[The_Grim_1]

9 hours ago, Mollotin said:

 

this is correct.

 

constant speed prop does not behave like a manual car transmission.

 

 

 

 

 

 

Exactly!  They don't act like any transmission. That's why I don't use one in my example. Notice how I said pick one gear and leave it there. 

 

Using a transmission to answer someone's question on "how does prop pitch affect RPM" has the problem (to me) that every time you shift gears in a car RPM goes up and down. Which can be confusing because the person is trying asking a question about RPM and you're using an example that makes you think about RPMs that work in a totally different way or ignore them going up or down every time you shift.

 

A CSP works on a single gear engine (why I said leave it in one gear),

with a throttle we more or less leave in place (stuck gas pedal because car pedals rest to zero) 

And the RPM changes because of the load that we are able to put on in (the hill). 

 

I'm trying to explain the force that is acting on the engine that causes it to slow down versus speed up. A transmission of any kind is not needed nor is it applicable. In fact it's totally unnecessary and can be confusing. Load is what's actually changing, not gear ratios or transmissions.  aircraft don't have a transmission in this case.

 

 

 

Edited April 15, 2020 by The_Grim_1

[SAS_Storebror]

If you think of a CSP like something that's set to keep the engine running at a set RPM all the time: Right.

If you think of top speed like something that always happens at the engine's maximum output RPM: Ehm... no, not necessarily.

It's not that easy.

In case of the P-47 for instance, the max. engine output might be at 2700rpm, however the thrust generated by the prop also depends on the prop efficiency, and this in turn depends both on speed and rpm (and pitch for that effect), and the product of [engine output] * [prop efficiency] doesn't necessarily reach it's peak at the engine's rated rpm.

 

You might want to read some additional literature on this matter.

A not-too-hard starting point would for instance be this: https://www.dglr.de/publikationen/2017/450176.pdf

 

Mike

[The_Grim_1]

I'm saying you use load on the engine to keep the RPM where you want it. We both understand how it works we're just explaining it differently. I don't see the need for a transmission or gear changes because there's not a direct correlation.

 

I understand how the p-47 and everything works I was just trying to do an "explain like I'm 5 years old" for the relationship between RPM and pitch nothing more. We're on the same page just trying to explain it differently. I'm not trying to explain anything about top speed, propeller efficiency or anything else. Just how pitch/load relates to RPM on a system with 1 gear and a fixed throttle. When the RPM is faster than you want put more load on.

Edited April 15, 2020 by The_Grim_1