P-40 Engine Settings as I found them (a bit weird)

[Venturi]

Unless you have actual Points to make, make none.

My point is simple. Your proposed changes are a feel good fix for a seriously flawed engine limits system for this a/c.

Edited April 4, 2016 by Venturi

[Venturi]

 

Why am I not surprised by such a response from you? So, you just hand-waved away everything else Greg wrote as being irrelevant?

Exactly.

[6./ZG26_Klaus_Mann]

My point is simple. Your proposed changes are a feel good fix for a seriously flawed engine limits system for this a/c.

But yours isn't any better. Basically giving it almost Limitless 70" would make it similar in Performance to an La-7. 

[Venturi]

lets get specific

 

What is the performance you speak of that the p40 will match?

 

Top speed? How so? Drag is exponential and can be adjusted. The P40 should get a few 20kph that's all. Again adjust if needed. I suspect it is a bit too fast as is.

 

Climb? Not so. This is s function of weight and wing, also drag and power. It will help but not like an La7 or even a 109F.

 

Acceleration, turn speed? Combat speed? Yes. These it will help, and these are what is needed if it is to realistically ever compete with even a 109e.

 

Also, 20 min is not limitless. The LW guys will tell you that.

Edited April 4, 2016 by Venturi

[6./ZG26_Klaus_Mann]

lets get specific

 

What is the performance you speak of that the p40 will match?

 

Top speed? How so? Drag is exponential and can be adjusted. The P40 should get a few 20kph that's all. Again adjust if needed.

 

Climb? Not so. This is s function of weight and wing, also drag and power. It will help but not like an La7 or even a 109F.

 

Acceleration, turn speed? Combat speed? Yes. These it will help, and these are what is needed if it is to realistically ever compete with even a 109e.

 

Also, 20 min is not limitless. The LW guys will tell you that.

With 1800+ HP at Sea Level the P-40 will always do more than 580kph, it's in the same Ballpark as all the other single engine fighters with that one, same as late model 109s, Fw190s and so on. 

Same in Climb. With 1800HP it will be better than anything, except maybe 109Gs and F-4s, and even those won't get away in a hurry. 20m/s or so can be expected up to 2000m

5 Minutes in a Dogfight are if you have that kind of Power behind it. 

 

 

 

Top speed? How so? Drag is exponential and can be adjusted. The P40 should get a few 20kph that's all. Again adjust if needed.

Nope, this game is not War Thunder or World of Tanks. They shouldn't just go around with the Adjustment Hammer just to balance stuff artificially. 

[Venturi]

drag is exponential so increases with speed as a square. The P40 would get approx 1470 hp at 52" and this would not affect speed too much. Just look at the docs floating around for the power curve. And the P40E top speed at critical altitude, in real life, WEP used is 355-360 mph, that is 15,500 ft. It gets 300 cruising at sea level in game right now. It's too fast already for its nominal as is. Top speed is not combat speed as the Russian source at the beginning of this thread so aptly put it. That's what the P40 needs in the game and that's what it got in real life from overboosting. And If you don't think things get adjusted in this game regarding FMs you're fooling yourself.

 

Ok if you and Crump are advising the devs then it's not looking too good. I'm typing on an iPhone and it's 430am. I've wasted enough time for one night on this trying to help. Good luck, good night.

Edited April 4, 2016 by Venturi

[Kurfurst]

Well Allison themselves tested it and determined up to 60" to be safe maximum after reports from frontline representatives. So, yeah that particular engine seemed to perform above its manual limits.

 

Frankly it should not be too hard to find out what the limits for the Allison engines are. It should be in their respective manuals.

 

Individual engines can be of course set to a higher setting, and as long as there is no knocking they might not be an immediate effect, but there is a reason why official boost clearances take quite long - they just have to make sure that the engine can withstand that output realiably, and not only just one engine for 10 minutes, but many many serial production engines for hours - so to account to reasonable production (and even fuel and maintenance !) tolerances, not just the "best case scenarios". 

 

Though that being said, I'd be much happier if the artificial time limits and "engine destroyed" states would be removed all and the only limit would be maintaining operational limitations, with perhaps some accelerated wear.

[6./ZG26_Klaus_Mann]

drag is exponential so increases with speed as a square. The P40 would get approx 1470 hp at 52" and this would not affect speed too much. Just look at the docs floating around for the power curve. And the P40E top speed at critical altitude, in real life, WEP used is 355-360 mph, that is 15,500 ft. It gets 300 cruising at sea level in game right now. It's too fast already for its nominal as is. Top speed is not combat speed as the Russian source at the beginning of this thread so aptly put it. That's what the P40 needs in the game and that's what it got in real life from overboosting. And If you don't think things get adjusted in this game regarding FMs you're fooling yourself.

 

Ok if you and Crump are advising the devs then it's not looking too good. I'm typing on an iPhone and it's 430am. I've wasted enough time for one night on this trying to help. Good luck, good night.

Good Morning. Well, I wouldn't have opened this thread is wasn't interested in raising the Engine Limits and at this point I see no point in raising them above permissible Engine Limits, since all other ingame Aircraft have to do the same. 

70" shouldn't be more than either a Kill-Assurance to use when you are jsut inches away from killing someone, or an Escape Setting. 

56" are still a perfectly good setting, 1500hp make it the most powerful inline fighter Engine ingame at that setting and good match for the P-40s weight.

and at 42" you have a solid combat mode, neither bad nor amazing. 

 

I don't have solid Evidence to support petitioning for more than what I offered above, and what I'm really after is not a Super-Über Top Notch Wondersetting, but a Solid, usable combat Set-Up. 

[JtD]

WRT what would the increased boost do to P-40 performance:

 

If we start with 42" boost, 3000rpm, sea level it develops 1050hp. 36"/2600rpm are just 900hp. Full throttle at sea level would give it 1750...1800hp depending on ram. According the the V1710-39 power chart. This would give it a serious performance boost, somewhere in between Klaus and Venturi's statements.

If you look at speed, with 42" you'll be at 470ish kph, figures vary. Going in with 1800hp will get you to around 560kph, give or take. It's not just an extra 20, but also not quite 580.

If you look at climb, 36"/2600rpm give you at around 1500fpm (7.5m/s), figures vary. Going in with 1750hp/3000rpm, you'll end up with around 3500fpm (18m/s), give or take 500. These figures were nearly achieved by later, lighter P-40N variants at 57" WEP.

 

Using this boost would certainly turn the P-40 into a competitive fighter. At sea level, at least. However, we must not forget that if the developers decide to ditch the current engine overload timer, they'll have to do it for all aircraft. This would certainly allow other aircraft to also use higher power settings for longer periods, thereby cancelling out some of the P-40s performance gains..

Edited April 4, 2016 by JtD

[Dave]

I see no point in raising them above permissible Engine Limits

Sigh. This is the essence of this protracted agonising conversation in one brief phrase.

You think only of _permissible_ whereas actual operators were compelled by circumstance to determine what was _possible_.

This reads so much like politicians stating that criminals can't use prohibited weapons to murder because they've been made illegal.

There is obviously truth in assertions that an engine manufacturer's recommended operating procedure was based upon what they believed to be best for the engine's serviceability and what the best non-destructive analysis of the day could tell them about its expected performance under various operating conditions.

Alongside this we have substantial documentary evidence from diverse sources who all corroborate real performance limits - for not just one special engine, but the entire flight line - well beyond the published "permissible" limits.

As far as I can gather this is not even disputed. Hell, Allison themselves wrote it down.

We don't get to pick and choose which historical source we can disregard. We can't just hand-wave and dismiss statements by people who were actually there as misunderstanding or misrecollections because they don't suit our argument.

 

So can we please move on from assertions that the guidelines were the only truth and that documented ubiquitous practice contrary to the rules was impossible because it wasn't advised - and just focus on determining with some clarity what those unauthorised but prevalent settings were.

[Dave]

Please see the following reply to my inquiry regarding the Allison V-1710-39 from an authoritative source:

Sounds familiar.

Greg's comments on first hand observations are completely consistent with conversations I had with both 3SQN North Africa veteran pilots and the two piston-engine combat veterans I had the privilege to be trained by in the early 90s.

My brother is still posted to 3SQN as a black-hander. I will ask if he can put his hands on any maintenance records or SOPs from the squadron's P40E operations or put me in touch with any still-living 3 SQN P40 drivers. Much of the oft cited "extreme" use of the P40E was by 3SQN and they have extensive historical records both within the unit and archived with the Australian War Memorial. My only request is that we establish the standards of proof before I waste other peoples' valuable time chasing this. I have my view on this but I want to hear from the detractors in specific terms what bar they wish to be held accountable to themselves.

[Venturi]

Detonation / preignition are a real issue and one of the major reason why high boost pressures are dangerous. To ignore that would also be unrealistic.

What people fail to realize is that the P40 represents a unique engine in real terms within the game structure. All other A/C currently modeled are limited by boost regulators whereas the Allison in the P40 is not. This means that to be realistic in terms of engine limits for this a/c (and the P39) a unique perspective must be used for this engine, specifically. Because absolute mechanical limits at altitudes below critical height are not limited by a manifold pressure regulator but by the operator's judgement and the flight parameters (speed, altitude, temp, etc).

I believe this quandry can be satisfactorily solved by eliminating the awful and unrealistic "hard timer" system and going with a variable timer based on engine state. It just takes interest in modelling engine limits correctly.

 

In my earlier suggestion about how to fix the problem, which does not require any sort of actual work to code more advanced calculations of engine loads in the game btw, the devs can report in the aircraft briefing the different engine levels for MAP and times to users that the manufacturers have rated as safe, and anything beyond those times for higher power states is a timing method based on the engine state (combat, climb, emergency, etc), which gives both each individual engine as well as different types of engines in general, as categories, differing and semi-random lengths of time in which above nominal settings can be used, before detonation sets in and severely damages the engine. As I've posted elsewhere in this thread for the actual mechanism (which is simplistic to be sure, but gets the point across).

 

 

 

Time to failure at power setting Y = (time constant) + (variable time interval, X)

X = power setting Y multiplier * (random time interval (0-10min))

Example possible result from such a system:

Time to failure at WEP = 5min + (1/2 [WEP multiplier] * RNG 0-10) = 5min + (1/2 * 7.23) = 8.615 min

 

It is less transparent to the user how long they actually have above the nominal approved limits at each power state, but the general range will get figured out by trial and error.

 

An alternative option would be to rework the entire engine management system so that dynamic loads are calculated and this would more accurately reflect how engines actually behave under stress. IE, you must throttle up slowly so no MAP spikes (assuming no regulator to save the engine), you must not lug the engine with high boost at low RPM, etc. High RPM with low boost is a low stress state while low RPM with high boost is a high stress state. You get my point. Anyways the above is an easier solution working within the current system.
 

Edited April 4, 2016 by Venturi

[Venturi]

Sounds familiar.

My only request is that we establish the standards of proof before I waste other peoples' valuable time chasing this. I have my view on this but I want to hear from the detractors in specific terms what bar they wish to be held accountable to themselves.

Quite. The reality is that aircrews had to know the actual limits of their machines as performance was a matter of life or death. In the Allison's case the limits were ABLE to be exceeded as the judgement of the pilot warranted (no regulator) and as the durability of the engine dictated (conservative limits in the manual). Historical reality is this was the way it was done.

Edited April 4, 2016 by Venturi

[Venturi]

WRT what would the increased boost do to P-40 performance:

 

If we start with 42" boost, 3000rpm, sea level it develops 1050hp. 36"/2600rpm are just 900hp. Full throttle at sea level would give it 1750...1800hp depending on ram. According the the V1710-39 power chart. This would give it a serious performance boost, somewhere in between Klaus and Venturi's statements.

If you look at speed, with 42" you'll be at 470ish kph, figures vary. Going in with 1800hp will get you to around 560kph, give or take. It's not just an extra 20, but also not quite 580.

If you look at climb, 36"/2600rpm give you at around 1500fpm (7.5m/s), figures vary. Going in with 1750hp/3000rpm, you'll end up with around 3500fpm (18m/s), give or take 500. These figures were nearly achieved by later, lighter P-40N variants at 57" WEP.

 

Using this boost would certainly turn the P-40 into a competitive fighter. At sea level, at least. However, we must not forget that if the developers decide to ditch the current engine overload timer, they'll have to do it for all aircraft. This would certainly allow other aircraft to also use higher power settings for longer periods, thereby cancelling out some of the P-40s performance gains..

 

JtD, I'm sure you have this already but just for everyone else. This is a good document, hope it helps. Note the hand-drawn in power curve at the top. Wonder why someone would do that...

Note that there is a hand note barely legible at the very top center which denotes an overspeed condition of 3200 rpm and full throttle power at sea level.

Edited April 4, 2016 by Venturi

[Venturi]

WRT what would the increased boost do to P-40 performance: .....................

 

 

And of course, all these figures immediately drop off once altitude increases above sea level. So at 2km you will see a BIG decrease in WOT performance, for instance. What this means is that top speed actually will not be higher than what it is currently... 355-360 mph... because the maximum boost possible by WOT is immediately reduced with altitude. Staying lower of course just means the air has more density, so the plane will be slower for a given power output... It all balances out. This means that all the benefits of this sort of thing in regards to raw power will be limited to very low altitudes. (ignoring the duration of the increased engine setting, which will be helpful at ALL altitudes)

 

Personally, I still don't see even a more realistic version of the engine modelling on the P40 producing anything close to 109F performance. However, it might make it competitive with the 109E, at low altitude - for short periods - and it really did have a chance, historically...

 

Although these sorts of fixes don't really address the real issues, for example, the P40 should be able to run a high RPM / lower MAP setting for a really long period of time, if not actually indefinitely - just like any other A/C engine... as this is a low stress state... talk about using propellor braking for landing with zero throttle... 3000rpm, 15" (vaccum) of MAP and it's WEP.... right

Edited April 5, 2016 by Venturi

[II./JG77_Manu*]

Fact is, that German pilots in 1942 respected both the P40C and the P40E. They were told "that only a stupid pilot would engage a horizontal turnfight with a P40". I have never heard something similar about the Yak1. In fact the first Yak, the Germans have been warned not to turn against was the Yak3. The P40E should be at least at the level of the Yak1 regarding  (sustained) horizontal turnfighting. In the game right now even a rookie pilot can laugh about that in virtually every 109. But nothing wrong with the FM, right...

Seriously even if full power and rpm would be cleared for a longer time, it wouldn't make the P40 a good dogfighter in this game. I tried already a few dogfights against friends in different 109s, and even in the 3 minutes i could use full power before the engine broke, i didn't really get into a good position against people i easily shoot down in the La5 or the Lagg. When turning with the P40 something seems seriously off. It feels like it has airbrakes out all the time, that much energy it's loosing. And that from a plane which was considered a very good sustained turner (not Spitfire level, but Yak level). I don't wanna use 1946 again, but in terms of FMs the newest iteration of HSFX is just a parade example in most cases. Anyone who wants to discuss about this plane, should also try it there, and you immediately realize what feels "off" in BoS. (in case anyone wants to jump in with the popular phrase about "known experience from former flight sims", i started BoS before 1946.)

Edited April 5, 2016 by II./JG77_Manu*

[6./ZG26_Klaus_Mann]

Fact is, that German pilots in 1942 respected both the P40C and the P40E. They were told "that only a stupid pilot would engage a horizontal turnfight with a P40". I have never heard something similar about the Yak1. In fact the first Yak, the Germans have been warned not to turn against was the Yak3. The P40E should be at least at the level of the Yak1 regarding  (sustained) horizontal turnfighting. In the game right now even a rookie pilot can laugh about that in virtually every 109. But nothing wrong with the FM, right...

Seriously even if full power and rpm would be cleared for a longer time, it wouldn't make the P40 a good dogfighter in this game. I tried already a few dogfights against friends in different 109s, and even in the 3 minutes i could use full power before the engine broke, i didn't really get into a good position against people i easily shoot down in the La5 or the Lagg. When turning with the P40 something seems seriously off. It feels like it has airbrakes out all the time, that much energy it's loosing. And that from a plane which was considered a very good sustained turner (not Spitfire level, but Yak level). I don't wanna use 1946 again, but in terms of FMs the newest iteration of HSFX is just a parade example in most cases. Anyone who wants to discuss about this plane, should also try it there, and you immediately realize what feels "off" in BoS. (in case anyone wants to jump in with the popular phrase about "known experience from former flight sims", i started BoS before 1946.)

Confirmation Bias.

When I go through the Wire I kill and eat whatever is stupid enough to engage me or my friends below 2000.

Don't forget that it is a 3.7 ton aircraft and I don't know what fuel settings you used, but on medium fuel it turns like a kitten on Crack.

It flies like a RoF Aircraft in many ways, you can pull back on the stick a lot harder than on many other aircraft and you have to coordinate you turns, keep the Ball Centered and you no longer have that Airbrake Effect. 

[Dakpilot]

Fact is, that German pilots in 1942 respected both the P40C and the P40E. They were told "that only a stupid pilot would engage a horizontal turnfight with a P40". I have never heard something similar about the Yak1. In fact the first Yak, the Germans have been warned not to turn against was the Yak3. The P40E should be at least at the level of the Yak1 regarding  (sustained) horizontal turnfighting. In the game right now even a rookie pilot can laugh about that in virtually every 109. But nothing wrong with the FM, right...

Seriously even if full power and rpm would be cleared for a longer time, it wouldn't make the P40 a good dogfighter in this game. I tried already a few dogfights against friends in different 109s, and even in the 3 minutes i could use full power before the engine broke, i didn't really get into a good position against people i easily shoot down in the La5 or the Lagg. When turning with the P40 something seems seriously off. It feels like it has airbrakes out all the time, that much energy it's loosing. And that from a plane which was considered a very good sustained turner (not Spitfire level, but Yak level). I don't wanna use 1946 again, but in terms of FMs the newest iteration of HSFX is just a parade example in most cases. Anyone who wants to discuss about this plane, should also try it there, and you immediately realize what feels "off" in BoS. (in case anyone wants to jump in with the popular phrase about "known experience from former flight sims", i started BoS before 1946.)

 

Where were these German Pilots encountering P40C and P40E in 1942...only a single SAAF squadron of 16 Tomahawks engaged in mostly anti shipping while most of the rest of P-40 were Kittyhawk MkII's and P-40 F's with Packard Merlin and many other changes

 

I thought the majority of E models were in the Pacific/CBI with USAAF, RAAF/RNZAF and China, the arrival of P40E in Western Desert early 41/2 prompted withdrawal of 109E, arrival of 109F prompted P-40F and others, this very roughly from memory

 

anyway we all know your campaign for P40 engine limits is just a "Trojan Horse" to get the Luftwaffe engine limits revised      LOL

 

Cheers Dakpilot

[JtD]

Sounds familiar.

Greg's comments on first hand observations are completely consistent with conversations I had with both 3SQN North Africa veteran pilots and the two piston-engine combat veterans I had the privilege to be trained by in the early 90s.

My brother is still posted to 3SQN as a black-hander. I will ask if he can put his hands on any maintenance records or SOPs from the squadron's P40E operations or put me in touch with any still-living 3 SQN P40 drivers. Much of the oft cited "extreme" use of the P40E was by 3SQN and they have extensive historical records both within the unit and archived with the Australian War Memorial. My only request is that we establish the standards of proof before I waste other peoples' valuable time chasing this. I have my view on this but I want to hear from the detractors in specific terms what bar they wish to be held accountable to themselves.

I don't know about "proof", but I'd be very interested in squadron records.

[Kurfurst]

I don't quite see how Tunisia or the Far East boost limitations are relevant to the Russian front though. After all you are flying a P-40 with Red Stars on it...

[Dakpilot]

Thought RAAf 3 SQN flew Merlin P40F's from mid 42 onwards, transitioned from Tomahawk Dec41 to P40E

 

Certainly does give a six month period of operating P-40E

 

Many other Squadrons had to make do with P-40M, not as liked as Packard version, it is to their credit and testament to their  record that they were given preference for the rest of the war until transitioning to Mustang III

 

Cheers Dakpilot

[JtD]

I don't quite see how Tunisia or the Far East boost limitations are relevant to the Russian front though. After all you are flying a P-40 with Red Stars on it...

The engine doesn't run any different just because the markings on the wings change.

[Dakpilot]

The engine doesn't run any different just because the markings on the wings change.

 

While this is very true, the Squadron which operated (P-40) at Stalingrad were there for two weeks before being decimated, withdrawn and retrained on La-5...

 

I feel there is a significant difference to operating an aircraft from where the groundcrew and Pilot's have quite a long history with the type and similar predecessors, 

 

I just dont see Russian mechanics/pilots with their training language and the "frontline war' situation being as comfortable with the equipment as those in the west, with closer factory ties and possible greater experience with Allison engines, since first USAAF experimental use in 1930

 

In fact Soviet doctrine of the time shows them sticking quite strictly to rules and regulations on pain of repercussions, often when common sense dictated otherwise, fortunately this attitude changed a bit later in the war

 

Cheers Dakpilot

[JtD]

In fact Soviet doctrine of the time shows them sticking quite strictly to rules and regulations on pain of repercussions, often when common sense dictated otherwise, fortunately this attitude changed a bit later in the war

Yes, the Soviets were famous for the use of small numbers of well maintained high quality equipment and minimum losses in combat. Never would they throw loads of cheap material and millions of poorly trained men into combat at horrendous losses.

It's a miracle they allowed even military ratings on their P-40's, given that the resulting extra wear and tear could reduce engine life expectancy from years to months and may even lead to an increase of their Stalingrad losses from 2000000 to 2000010.

 

(I understand your other points, but I don't think it applies/matters much.)

[Dakpilot]

re doctrine, I don't think it's really about saving extra wear and tear, but as a squadron commander I would be very reluctant to report to Moscow that I now have no serviceable aircraft available to support the front, due to unauthorised use departing from limits in the manual on a fairly unfamiliar 'foreign' aircraft type, especially with the political officer looking over my shoulder..

 

Soviet Russia in 42 was not "tally ho'' in the Western Desert or "good on yer cobba" in PNG, however brutal and hard those campaigns also were

 

 

Cheers Dakpilot

[Venturi]

What you don't seem to realize is that no-one could prove jack-all when it comes to throttle usage. The pilot was in control, and the pilot can do whatever he wants when that 109F is coming in. Soviets were more concerned about killing Germans than about engines. In fact they even went so far as to authorize a complete re-design of the P40 using a native engine since spares were not around - they converted a number of airframes, but because the native engine put out less power, this idea was abandoned after the conversion was completed and the planes were tested.

 

RE the other points made about the experience of the pilots with the engines, I think this holds more water - but BOS/BOM is modelling what the aircraft were capable of, not what the experience of particular groups of pilots was in regards to how to use the airframe to the fullest extent. In the documented cases of western pilots utilizing higher settings, all we are showing is that the aircraft was capable of sustaining these power levels. If we had Soviet documents showing that, you can be sure we'd be using them. Unfortunately for us there are no Soviet complaint letters from front line representatives to Allison or Soviet Air Command documenting the use of overboosting practices as being rampant.

Edited April 5, 2016 by Venturi

[216th_Lucas_From_Hell]

On the opposite the shortages were striking and pilots really did have to work their ass to bring aircraft back in one piece. A. Klubov was badly burned because he made sure to crash-land his Chaika even though it was engulfed by flames. Pokryshkin dragged a crash-landed MiG-3 with a truck until he found an airfield and handed it off to a superior there before returning to his regiment. The under-wing UBKs were removed in multiple regiments because other aircraft needed UBs and they couldn't afford to keep some MiG-3s with 3.

 

16 GIAP had eight Yak-1s and zero MiG-3s in the autumn of 1942 before refitting. Pilots were sunburnt and overstressed, and there were only about ten of them left while the rest went missing after a trip to a repair facility with most aircraft. Keeping aircraft was mandatory, while also holding back an enemy offensive. It was dark stuff, and by no means wasteful pouring.

[Dakpilot]

What you don't seem to realize is that no-one could prove jack-all when it comes to throttle usage. The pilot was in control, and the pilot can do whatever he wants when that 109F is coming in. Soviets were more concerned about killing Germans than about engines. In fact they even went so far as to authorize a complete re-design of the P40 using a native engine since spares were not around - they converted a number of airframes, but because the native engine put out less power, this idea was abandoned after the conversion was completed and the planes were tested.

 

RE the other points made about the experience of the pilots with the engines, I think this holds more water - but BOS/BOM is modelling what the aircraft were capable of, not what the experience of the pilots was in regards to how to use the airframe. In the documented cases of western pilots utilizing higher settings, all we are showing is that the aircraft was capable of sustaining these power levels. If we had Soviet documents showing that, you can be sure we'd be using them. Unfortunately for us there are no Soviet complaint letters from front line representatives to Allison or Soviet Air Command documenting the use of overboosting practices as being rampant.

 

No but we do have Golodnikov mentioning that he pushed his P-39 ''through the wire" one single time, this does not seem to me to indicate 'rampant overboosting practices', also mentioning several  ways of getting extra performance (in technical detail) but never mentioning overboosting (p-40)    but does mention frequently the drawbacks of Russian grade fuel and oil

 

as a counterpoint, one persons experience does not make up an entire airforce...

 

I guess it is a hard topic to prove one way or the other, Russian actual use, rather than 1942/3+ western experience 

 

Cheers Dakpilot

Edited April 5, 2016 by Dakpilot

[Venturi]

No but we do have Golodnikov mentioning that he pushed his P-39 ''through the wire" one single time,

 

Was it a later P39 with MAP regulator, or not?

On the opposite the shortages were striking and pilots really did have to work their ass to bring aircraft back in one piece. A. Klubov was badly burned because he made sure to crash-land his Chaika even though it was engulfed by flames. Pokryshkin dragged a crash-landed MiG-3 with a truck until he found an airfield and handed it off to a superior there before returning to his regiment. The under-wing UBKs were removed in multiple regiments because other aircraft needed UBs and they couldn't afford to keep some MiG-3s with 3.

 

16 GIAP had eight Yak-1s and zero MiG-3s in the autumn of 1942 before refitting. Pilots were sunburnt and overstressed, and there were only about ten of them left while the rest went missing after a trip to a repair facility with most aircraft. Keeping aircraft was mandatory, while also holding back an enemy offensive. It was dark stuff, and by no means wasteful pouring.

 

Oh yes, quite. All I'm saying is that the pilots were not constrained by some political officers' "looking over their shoulder" but rather the true capabilities of the aircraft. Allisons were known to be quite reliable and in comparison to Merlins were the better engine in this regard. I highly doubt non-necessary abuse occurred. However, I am sure that when RISK ASSESSMENT was taken of being killed or getting a tighter turn, then the throttle was increased.

[JtD]

On the opposite the shortages were striking and pilots really did have to work their ass to bring aircraft back in one piece. A. Klubov was badly burned because he made sure to crash-land his Chaika even though it was engulfed by flames. Pokryshkin dragged a crash-landed MiG-3 with a truck until he found an airfield and handed it off to a superior there before returning to his regiment. The under-wing UBKs were removed in multiple regiments because other aircraft needed UBs and they couldn't afford to keep some MiG-3s with 3.

 

16 GIAP had eight Yak-1s and zero MiG-3s in the autumn of 1942 before refitting. Pilots were sunburnt and overstressed, and there were only about ten of them left while the rest went missing after a trip to a repair facility with most aircraft. Keeping aircraft was mandatory, while also holding back an enemy offensive. It was dark stuff, and by no means wasteful pouring.

Exactly the point why any pilot would resort to using higher boost in combat - to survive, and bring the aircraft home. I'm pretty sure our armchair comfort somewhat clouds the judgement about how slow you want to go into combat, be it enemy fighters or AAA. The real engine didn't stop because some programmer put a time limit into the code for lack of a sophisticated engine model, and the real pilot would not hit refly after a 37mm took off his slow-and-easy-target-wing.

 

And for Dakpilot again - there's no wire on the P-40. You control throttle directly, and even if you just forgot to gradually close it in a descent, you'd fly at excessive boosts.

Edited April 5, 2016 by JtD

[Venturi]

And for the last time - there's no wire on the P-40. You control throttle directly, and even if you just forgot to gradually close it in a descent, you'd fly at excessive boosts.

 

Precisely. It was relatively management intensive - and why this particular aircraft represents an "unmasking" of the engine management system in game, and why it is in everyone's best interest to have it looked at.

 

It is still more advanced than the Db601A - 109E-3/4 system without prop pitch management, which was similar in its challenges.

 

And keep in mind the P40E was a 1940/41 design which was competitive with its contemporaries.

[Dakpilot]

But how were the throttle stops rigged? in a default factory aircraft

 

Cheers Dakpilot

[=362nd_FS=RoflSeal]

Was it a later P39 with MAP regulator, or not?

 

Oh yes, quite. All I'm saying is that the pilots were not constrained by some political officers' "looking over their shoulder" but rather the true capabilities of the aircraft. Allisons were known to be quite reliable and in comparison to Merlins were the better engine in this regard. I highly doubt non-necessary abuse occurred. However, I am sure that when RISK ASSESSMENT was taken of being killed or getting a tighter turn, then the throttle was increased.

 

It was in relation to War Emergency Power settings on different fuels in P-39Q.

 

If it was running on Russian B-95 fuel, WEP would be set as 51". If American fuel, 57".

Advancing the throttle past 51" was blocked with a wire if it was running on russian fuel.

[Venturi]

Again, settings which could be used to achieve the above, which take into account both the operating manual limits for engine longevity as tested by manufacturer, as well as additional variables which take into account the historical information that is available as to how these engines were actually used. It could look something like the following:

 

General formula:

 

Time to failure at power setting Y = (time constant) + (variable time interval, X)

X = power setting Y multiplier * (random time interval (0-10min))

 

Examples for Allison V1710-39:

Time to failure at Overboost (70") = 1min + (1/3 [Overboost multiplier] * RNG 0-10) = 1min + (1/3 * 4.12) = 2.37min

Time to failure at WEP (52") = 5min + (1/2 [WEP multiplier] * RNG 0-10) = 5min + (1/2 * 7.23) = 8.62min

Time to failure at Military (44") = 5min + (4/5 [Military multiplier] * RNG 0-10) = 5min + (4/5 * 6.12) = 9.90min

 

MAP should be limiting factor for time at power state, not RPM (unless in overspeed of engines, as is possible in system without automatic prop governor, and in a situation in which absolute Max RPM as dictated by the Operating Manual is exceeded for a length of time - this can lead to rapid failure). The time limits for each engine can be initialized at the beginning of the sortie and remain with that aircraft until the sortie is over. The time limits should be additive/subtractive. So that time spent at each level higher up subtracts from the time available beneath it, and the time available is used up from the time provided from lowest power level to the highest. So in the top example,

 

Time to failure at overboost = 2.37min

Time to failure at WEP = 2.37min + 8.62min

Time to failure at Military = 2.37min + 8.62min + 9.90min

 

In the above example, this means that if I was to use 8.62min of time at WEP, then I would have 2.37min of overboost remaining and/or 2.37min of WEP remaining, and 2.37 + 9.90min of Military remaining. If I were to use all 10.99min of time at WEP, then I would have no time remaining at overboost or WEP settings, and 9.90min of Military remaining.

 

This takes into account both the Operating Manual limits, which have been tested by manufacturer for engine longevity, and a random factor which can be adjusted for historical exigencies and need not be so exact as the operating manual limits, (due to engine hours, engine design or quality of manufacture, etc - in the case of the Allison for instance, make this time longer than normal, etc).

 

----

 

If the devs wanted to get really creative and be even more realistic, it would be simple: They could also implement a minimum RPM that the engine had to be at before a certain boost could be used, using power settings from the Operating Manual. This would take into account the high likelihood of detonation with high boost/low RPM settings. This could look something like:

 

General formula:

 

Time to failure for boost/RPM mismatch at boost level Y = (time constant) + (variable time interval, X)

 

X = boost level Y multiplier * (random time interval (0-2min))

 

Examples for Allison V-1710-39:

 

Time to failure at Overboost (70") with RPM significantly below 3000 = 0.25min + (1/3 [Overboost multiplier] * RNG 0-2min) = 0.5min + (1/3 * 1.12min) = 0.62min

Time to failure at WEP (52") with RPM significantly below 3000 = 1min + (1/2 [WEP multiplier] * RNG 0-2min) = 1min + (1/2 * 0.84min) = 1.42min

Time to failure at Military (44") with RPM significantly below 2800 = 2min + (4/5 [Military multiplier] * RNG 0-2min) = 2min + (4/5 * 1.53min) = 3.22min

 

Again, the random variable can be set per sortie. These would be SINGLE INSTANCE, subtractive limits, and the timers would reset each time the condition of low RPM/high boost was met and then cleared by correcting the mismatch.

 

An example from the above limits might be:

 

2000 RPM + WEP power for 1 min, means I have 0.42min remaining before engine detonation. If I THEN advance power to Overboost and still keep 2000 RPM, detonation occurs: 0.62min allowable time at Overboost mismatch, minus 1min (WEP mismatch) = -0.38min = engine detonation.

 

Short engine status messages on screen can inform the user what they are doing wrong.

 

Obviously if the engine has automatic RPM/boost matching, as in the case of most of the currently modeled German aircraft, the above RPM/Boost management would be a non-issue (unless the system was disabled) - and would reflect the historical superiority of these systems over the contemporary Allied prop pitch systems.

 

---

 

Starting with the P39J, there was a MAP limiter.

 

It was in relation to War Emergency Power settings on different fuels in P-39Q.

 

If it was running on Russian B-95 fuel, WEP would be set as 51". If American fuel, 57".

Advancing the throttle past 51" was blocked with a wire if it was running on russian fuel.

Edited April 5, 2016 by Venturi

[=362nd_FS=Hiromachi]

|I only wish that my engine wouldnt be instantly damaged after exceeding the 1 minute limit. 

Because the warning in form of "emergency time limit exceeded" is more like death sentence than information. There should be either information that you are about the exceed the limit or we should get rid of that information at all, since it helps nothing. 

 

Best would be of course more natural system of damaging the engine, more randomized and not always leading to permanent destruction of the engine as it is now. 

[Dakpilot]

That's great in principle  

 

 but I reckon it would lead to more blown engines with people not knowing where the limits lie, and even more frustration for some  or maybe I missed something

 

Just a thought

 

Cheers Dakpilot

[Venturi]

It is simple in practice and most people would get it - you could still get warnings on screen. Anyone who has driven a stick-shift car has figured our how to use the engine, right? This is sort of the same thing, but with beasts of supercharged 1000hp+ V12 engined prop planes.

 

Each state change or engine condition would be noted and the devs could even put in a note on screen about the nominal time available per the operating manual.

 

(Users should figure out the additional time additive factors on their own - variability from plane to plane, and sortie to sortie, adds to the fun and realism! As long as a base amount of safe time is known to all.)

 

Such as:

 

"Engine Warning

(WEP power, 5min nominal)"

 

And if the RPM/boost mismatched, then:

 

"Engine Warning

(RPM/Boost mismatch)"

 

Those who could not deal with the complexity of having to manage their engine RPM would fly the easy-to-handle 109 or other German designs anyways.

 

I could also go on about how the fuel/air mix could play into timers, too. Get too rich and it loses power, and starts minor smoking. Get too lean it loses power, and then will detonate at even more lean mixes - this safety margin is reduced at higher boost levels. But maybe that's a step too far. 

Edited April 5, 2016 by Venturi

[=362nd_FS=Hiromachi]

That's great in principle

 

 but I reckon it would lead to more blown engines with people not knowing where the limits lie, and even more frustration for some  or maybe I missed something

 

Just a thought

 

Cheers Dakpilot

Regardless of great, it is useful. What am I supposed to do with the information that I've exceeded the limit and my engine is now permanently damaged ? 

Most of the time in campaign I wont be even able to make it back to airbase. 

 

However if I'd be notified that I'm about to exceed the limit I could certainly do something.

 

And yeah, you must have missed logic, it cant lead to more blown out engines if they are already getting blown every single time one exceeds the limit. 

[Venturi]

The sim is so great in all sorts of other ways, the engine management I am suggesting is still far from what DCS imposes, but it would be a reasonable amount for people flying "expert" level in BOS/BOM.

[Dakpilot]

My only point was that if there is a known time limit one can plan with that, if it is variable you are playing a guessing game and to be safe you will maybe have to be as conservative as it was before

 

Don't get me wrong, I am all for more extensive options in engine management

 

Cheers Dakpilot