Jump to content
6./ZG26_Klaus_Mann

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

Recommended Posts

First Test I did was at 43.9 inches and 3000, the highest Setting I found in any Document, showed as "Emergency Mode"

After 3:20 Minutes Message "Combat Mode Time Exceeded"

After 5:00 Minutes Message "Emergency Mode Exceeded"

After 5:30 Minutes Severe Engine Damage and Seizure. 

 

Second Test was 43.9 Inches at 2800, ingame setting "Combat Mode"

After 3:20 Minutes Message "Combat Mode Time Exceeded"

After 7:30 Minutes Engine Damage and Seizure occured. 

 

Third and Most Fun Test 70 inches at 3000 "Emergency Mode"

After 2:00 Minutes Message "Emergency Mode Time Exceeded"

After 2:30 Minutes Engine Damage and Seizure

 

Apparently Combat Mode never lasts much longer than 3 Minutes, but is very flexible.

In general Combat Mode time seems too short, but anyways, it is quite weird not having a long term Raised Power setting. 

 

Edit: Corrected 57" for 70"

Top speed at 70" is 585+kph at Sea Level

Edited by 6./ZG26_Klaus_Mann

Share this post


Link to post
Share on other sites

P-40E's Allison engine is borked and is more fragile then a chandelier when it was completely the opposite in real life

 

Nov 1941 engine datasheet limits

 

 

P-40E_Operation_Instructions.jpg

 

 

 

Dec 1942 datasheet engine limits

 

 

nFbmOHh.png

 

 

 

Note extension of military power to 15 minutes and addition of WEP at 56".

 

Allison report of overboosting V-1710-39 and -73 in MTO and PTO

http://www.raafwarbirds.org.au/targetvraaf/p40_archive/pdfs/Allison%201710-39%20abuse.pdf

 

 

"Some pilots admit operating for prolonged periods at around 70" Hg of boost"

 

... from the Middle East our Representative who just returned advises that they are resetting boost controls to 66" Hg... this company has agreed to war emergency operation at 60" manifold pressure"

 

... "The 60" war emergency rating on the 8.8 blower ratio was somewhat further from detonation point but was limited by structural limitations of the engine to the 60" value. We therefore feel, that with the tendency to pull out manifold pressure such as 66" to 70" on 8.8 blower, a bad precedent is being established which may cause numerous failures when the 9.6:1 supercharger gear ration engines are recieved  in the field."

 

Report on use of Mustang Mk I (same engine)

http://www.wwiiaircraftperformance.org/mustang/e-geh-16.html

 

 

  33.       This aircraft is powered with the Allison 1710-39 engine having a rated power of 1150 H.P. at 3000 R.P.M. and 44” Hg. at 12,000 ft. The engine was originally equipped with an automatic boost control limiting the manifold pressure at the lower altitudes to 44”. The British remove this so as to get the vastly increased performance at lower altitudes thru the judicious use of over-boost. As has been mentioned before, they have had exceptionally good service out of these engines and due to its smoothness at low RPM’s, they are able to operate it so as to obtain a remarkably low fuel consumption giving them an operational range greater than any single engine fighter they possess (the fact that the Merlin engine will not run well below 1600 prevents them from obtaining an equivalent low fuel consumption and therefore limits its usefulness for similar operations).

 

   36.       In view of the British operation and the fact that we have an approved war emergency rating on the 1710-39 engine of 56”, it is suggested that immediate steps be taken to remove the automatic boost controls from our P-51 airplanes in this theatre and that the instrument dials be marked with the proper lights. The British have operated at full throttle at sea level (72” Hg) for as much as 20 min. at a time without hurting the engines. According to them, the Allison is averaging 1500 hours between bearing failures as compared to 500 to 600 hours for the Merlin. The Allison, they have found, will drag them home even with the bearing ruined.

 

I also did some tests a month ago or so

 

 

 

Real life "War Emergency Power" 50"+ @3000rpm        

WEP time exceeded 2:00
Combat time exceeded 3:20
Engine damage ~3:40
Notes: Real life limit 56"@3000rpm 5 minutes (1942), numerous cases of extended time use of 60"+, numerous enough to have Allison themselves give a response.
 
Real life "Military Power" 45"@3000rpm
WEP time exceeded 2:15
Combat time exceeded 3:15 (really surprised at this one)
Engine damage ~4:05
Notes: Ingame this powersetting is classed as "War Emergency Power", when no document calls it such and it cannot even do the 1941 requirement of 5 minutes, never mind 15 minutes that was given in 1942
 
1942 "Take off Power" 45"@2800rpm (Climb at 160mph as per manual)
WEP time exceeded 3:20
Combat time exceeded 3:25 (Combat power time seems to be unnaffected by things like RPM or Manifold Pressure)
Engine damage ~5:15 (note: engine unable to keep 45" after 5 minute mark (~9,500ft) as altitude increased, engine damage at 41")
 
Stalingrad autumn
 
All series of tests auto rads (but checked guages to check within parameters) and first two were level flight at 1000m. 3rd test was takeoff from runway.

 

 

Edited by RoflSeal
  • Upvote 5

Share this post


Link to post
Share on other sites

There is definitely an issue here, however it may not be as simple as it seems, I don't think it is entirely reasonable to directly compare practices in the west with the results which were had in the Russian front.

 

There is certainly enough evidence that VVS pilots ran their Allison's hard, witnessed by the very quick reduction in squadron effectiveness in combat and rather quick use of the spares available, even to the point of trying retrofitting (not very successful as far as performance)  the Klimov 105

 

But considering that they were not as familiar with the engine as those using it in the West, did they also routinely remove the boost limitation as the British and Australians did?

 

More importantly did they have the same quality fuel and oil available in frontline combat as Western A/C, this is very important, as mentioned in some of the above documents, even with high octane fuel, pre-ignition could destroy an engine in 30 seconds.

 

In Russian service Western aircraft generally never had the same success/longevity/performance (Spitfire/P-40) as found in the West,  however the P-39 also with Allison engine was much preferred, and did see good use mainly with the Guards "Elite' Regiments, what were the 'overboosting' practices with this aircraft in VVS service (not the exact same model Allison however) or was it that it's success with VVS came in a later period of the War when supply/experience was improved

 

When considering the familiarity/experience and information availability Western maintenance staff/engineers had with the P-40/Allison and the difference in logistics and spares that they experienced, it does not seem surprising that Soviet records would paint a slightly different picture than that of the RAF/RAAF/SAAF and USAAF

 

none of the above is a statement of fact, just some points for discussion, I am no expert on the subject and they are only general points.

 

If the P40 E-1 was presented in this situation for Western Desert or CBI/Far East theater there are certainly precedents to support better performance limitations

 

Cheers Dakpilot

 

(P.S. And now time for me to unintentionally offend many  ;) am I the only one one who hates the term 'Borked' as soon as I read it I get the desire to disregard everything else as a World of Warplanes/Need for speed or suchlike type rant...sorry, maybe it is just me)

Share this post


Link to post
Share on other sites

Fun fact is that the Soviets ran the P40 even harder then the west..according to pilot accounts full throttle for unlimited times. Of course the aircraft degraded rapidly, as did other types like the Klimov. But that doesn't change the fact, that they ran this bird full throttle regularly, and since this Sim does model factory fresh aircraft only, that should be all what matters. Other stuff like low grade fuel and oil from the Soviets isn''t modeled for all the Russian aircraft, so why should it for the P40. That's no argument.

Soviet's had very lax engine limitations in their manuals, since they could replace their engines in high numbers. Allison piece time manual (which is used currently for modeling the P40 engine limitations) had a very very strict engine limitation, since it's there to preserve the engine as long as possible (piece time use). Taking this data as benchmark for the radical engine limits (aka engine will die) is not correct at all, in fact that is pretty much having double standards.

You really shouldn't have double standards in a Sim, but regarding engine limits, that's what we have at present.

Share this post


Link to post
Share on other sites

The fuel argument is quite valid, Russian aircraft were designed to run on Russian grade fuel/oil P-40 was not, the Russian aircraft performance is modeled on available Russian (lower octane grade) fuel, I mentioned this as a point of discussion (of course there was limited imported high octane fuel available for the Western aircraft), but your statements 'as facts' are not quite so accurate to dismiss it as 'that's no argument'

 

I brought it up as a position of thought as to why Russian operation/perception  may have been different to Western practices, were they familiar enough to remove the factory boost limitation? notwithstanding operating at (overcautious factory) designed 'full throttle'

 

Damage from detonation at high boost is a very real thing as mentioned in the above U.S. documentation (30 seconds from onset to  failure) and I have a lot of experience trying to operate high performance large piston engines on lower grade fuel due to operational needs and logistical issues

 

I also don't think you should call it 'double standards' that has an entirely different inference of something deliberate or underhand, it is just a wrong data point in a performance parameter

 

As usual it was silly to think of discussion when all is met with opinions stated as facts

 

Cheers Dakpilot

Share this post


Link to post
Share on other sites

Not knowledgeable enough to partake but two notes:

 

All lend-lease aircraft ran on lend-lease fuel brought by convoys and through Iran. The idea that lend-lease aircraft ran on lower-octane fuel at any time is a misconception.

 

About the factory limitations, these were British aircraft, some of which had seen some service, so it is probable that the British had removed the limiters right off the bat.

 

Supplies were a big problem though, lack of spares regularly grounding aircraft back in 1941 and 1942.

  • Upvote 1

Share this post


Link to post
Share on other sites
The fuel argument is quite valid, Russian aircraft were designed to run on Russian grade fuel/oil P-40 was not, the Russian aircraft performance is modeled on available Russian (lower octane grade) fuel, I mentioned this as a point of discussion (of course there was limited imported high octane fuel available for the Western aircraft), but your statements 'as facts' are not quite so accurate to dismiss it as 'that's no argument'

Lucas already answered to this, so i don't have to further comment.

 

 

 

I brought it up as a position of thought as to why Russian operation/perception may have been different to Western practices

Who says that Russian operation/perception was different then western? As fas as i know Russians quite valued the P40 until around 42, in addition multiple Russian fighter groups were upgraded from I16 and Mig3 to P40. Upgraded. Be honest with yourself for once, would you call it an upgrade from in-game Mig3 to in-game P40?

 

.

 

I also don't think you should call it 'double standards' that has an entirely different inference of something deliberate or underhand, it is just a wrong data point in a performance parameter

 

Double standards means double standards, i never said that it's something deliberate, or bias-affected, don't try to imply that nonsense again. Using lax war-time manual on one side, and piece time manual on the other side for the same kind of effect in game is having double standards, you can twist and turn it like you want, that doesn't change a thing.

 

The rest of your statement says enough, [Edited] - no comment

Share this post


Link to post
Share on other sites

Soviet standard aviation fuel for Klimov engines was 3B-78 which had around 95 octane with addition of R-9 additive.

For M-82 it was 4B-78 (and also for Mikulin) with roughly same octane nr (95) with R-9 additive. Main component of additive was TEL (tetraethyl lead) delivered from USA.

At the outbreak of the war in june 41,situation with aviation fuel was critical,least to say. B-78 fuel was in very short supply and it would not surprise me if soviets were using whatever lower grade fuel (70-74) available.

Nice article here

 

http://www.oilru.com/or/47/1006/

  • Upvote 1

Share this post


Link to post
Share on other sites

Russians flew the P-40 (and P-39) "maxed out"

 

http://www.warbirdforum.com/russp40.htm

 

 

Golodnikov: Main difference in the assesment of P-40's combat capabilities comes from that we and Allies had completely different exploitation of the aircraft. They use it as written in manuals, from letter to letter. We, as I said before, had a main rule is to take from the machine everything possible. How much "everything" is, it did not write in manuals, and even airplane designer didn't anticipate. This appears in combat. Everything said above goes for Aircobra, too. Have we flown them how Americans wrote it in the manual, we would all got shot down. It was a dud as the fighter aircraft on "birth" regime. On our regimes we had a equal combat with either "Me's" or "Fw's", but it would have meant 3-4 combats with subsequent engine change.

Share this post


Link to post
Share on other sites

I do not claim to be an expert on lend lease aircraft, only from what I have read, Osprey's Lend lease Aces mentions the lesser performance of Hurricanes when using local fuel and, Curtiss P-40 WWII Album mentions the problems of 'burnt out' engines with difficulties of the more demanding need for more advanced fuel and purer oil, Spitfires in Kuban had a much (documented) shorter engine life that those used in the west

 

If people with greater knowledge and experience than me of the subject say only imported fuel was used in lend lease aircraft, fair enough. My point was only that with a lower grade fuel higher boost is unwise, from personal experience

 

 and since this Sim does model factory fresh aircraft only, that should be all what matters. Other stuff like low grade fuel and oil from the Soviets isn''t modeled for all the Russian aircraft, so why should it for the P40. That's no argument.

 

 

Clearly that is not a correct statement, All the Russian aircraft performance is based on their lower fuel grades that they were designed for, also the bearings were of a type suited to their own produced oil, 

 

It is that statement (bolded) that I do have a problem with, because it certainly imply's something, which Lucas did not deal with

 

I would also say as far as ' lax engine limitations in their manuals' it was more of a design intent/ philosophy that they could be operated in that way, think Ak47 vs M16

 

If pointing out something that is not correct is classic Dakpilot then Cheers  ;)

 

And I still stand that double standards, by its definition means bias, it is just not a good phrase to use, simply that

 

Cheers Dakpilot

Share this post


Link to post
Share on other sites
Clearly that is not a correct statement, All the Russian aircraft performance is based on their lower fuel grades that they were designed for,

Brano pointed out, that Mig3 was designed for 95 octane..lately i read about the Mig3, some low 80 octane used during 41. So i guess it was a correct statement after all. I am not saying that Russian aircraft in game are designed as using 110+ octane. But around 95. The Soviets however didn't have a lot of 95octane fuel in the beginning of the war, and used their best fuel for lend lease aircraft, if possible (as Lucas pointed out already)

 

 

 

I would also say as far as ' lax engine limitations in their manuals' it was more of a design intent/ philosophy that they could be operated in that way, think Ak47 vs M16

Nothing against the lax interpretation in their manuals, but setting the piece time manual of the P40 at the same stage is utter nonsense, like already said quite a few times.

 

 

If pointing out something that is not correct is classic Dakpilot then Cheers

Trying to discredit other people with undermining passive-agressive comments, and word-twisting is typical Dakpilot, been that way for over 2 years

 

 

And I still stand that double standards, by its definition means bias, it is just not a good phrase to use, simply that

Call it what ever you like. It's just ridiculous how you just try to distract from the problems this game has, and had, in virtually every discussion. Been that way back then when the 190 was badly broken, been that way with the Yak flaps, and now it's the case with the P40. You try to distract from the problem, one of your means trying to discredit the author pointing out those problems. This is just getting sillier the more you can read it.

Only hurts the game, when anyone who discovers an error in the game doesn't dare to get public with it because of fearing to get discredited by the likes of you.

Edited by II./JG77_Manu*
  • Upvote 1

Share this post


Link to post
Share on other sites

So it seems like Soviets flew them in way higher power settings then westerners..seems like the engine limit should be way more expanded then in a western scenario. Thanks for that source, didn't know about that yet.

 

The full 4 part  Goldnikov (source) article is a bit more revealing, and highly recommended, he mentions a single occasion of him 'breaking the wire' and using max boost (P-39) also of regularly using Soviet fuel in P-39 and using lower boost ratings (knew I read that somewhere before elsewhere), mostly the talk of P-40's higher 'performance' use is keeping a much higher cruise speed and higher revs than recommended, and using full rich instead of auto rich mixture to get more power

 

However it is best to read the Whole lengthy interview and digest it rather than cherry pick a few sentences

 

 Nikolay Gerasimovich, you constantly say that the basic Soviet fighters, the Yak and the Lavochkin, were equal to the German fighters in speed, although reference books contradict this. According to reference data, German aircraft always have superiority in speed. How do you explain this difference between reference data and practical data?

 

What have we been talking about? You must understand that you have been making the same mistake as do all people who have no connection with combat aviation. You are confusing two concepts: maximum speed and combat speed. Maximum speed is attained under ideal conditions: horizontal flight, strict maintenance of altitude, calculated engine revolutions, and so on.

Combat speed is a range of maximum possible speeds that an aircraft can develop for the conduct of active maneuver aerial battle, and at which all forms of maneuver attendant to that battle can be executed.

When I speak to you about speed, I have in mind namely the combat speed at which I conducted battle. To me maximum speed is neither here nor there

 

Understand that if you look at German fighters, either the Messer or the Fokker, their combat speed was 80—100 kmh [50—60 mph] lower than their maximum speed. As far as I know, British and American aircraft of this period were analogous in this respect to the German fighters. This relationship of speeds of the Western aircraft was maintained for the duration of the war. The difference between maximum and combat speeds of the Yak was on the order of 60—70 kilometers [35—40 mph], and during the second half of the war even less. The Yaks were the most dynamic and lightest fighters in the Soviet VVS and therefore were very good in vertical maneuver. Throughout the war a standard, average, adequately trained pilot in Yaks could contend with Messers on a par. At the beginning of the war the Yak was any pilot’s dream.

 

 http://lend-lease.airforce.ru/english/articles/golodnikov/index.htm

 

and by the way I am not saying the P-40 limitations as we have now are correct  :)

 

Cheers Dakpilot

Share this post


Link to post
Share on other sites

 

 

 

 

 

Call it what ever you like. It's just ridiculous how you just try to distract from the problems this game has, and had, in virtually every discussion. Been that way back then when the 190 was badly broken, been that way with the Yak flaps, and now it's the case with the P40. You try to distract from the problem, one of your means trying to discredit the author pointing out those problems. This is just getting sillier the more you can read it.

Only hurts the game, when anyone who discovers an error in the game doesn't dare to get public with it because of fearing to get discredited by the likes of you.

 

This is your trouble I have never disagreed that there are issues, but the way some have gone to argue about them, there is not much wrong with the FW190, and some think it should out roll an I-16, it is other a/c that seem to be over performing, I always said there is something wrong with the Yak flaps but defended its operation and speed limits from examples in the actual manual

 

Maybe if you actually read my posts you would see that I also want historical accuracy but fixed in the correct way not by 'Yakcopter' mob they should rip off at 150kmh mentality 

 

Cheers Dakpilot

Share this post


Link to post
Share on other sites

Stay on Topic Please. I'm sure that slowly but surely the 190 will be adressed, the information is already out there.

If you can add to the conversation about the P-40 engine limitations please do so, let's not derail this, please. 

Thx. 

Share this post


Link to post
Share on other sites

That article I linked speaks about only 4% of total fuel production in 1941 for B-78 fuel needed for all new aircrafts. Clearly vast portion of VVS units was left with low octane fuel. It is also on of the reasons why units reequipped with new generation of fighters did so poorly in their training effort before war broke out. There was not enough fuel for everyone and they had to rely on U-2 and UTI-4 trainers while their newly arrived migs,laggs,yaks were standing grounded. It of course didn't change to better after 22nd June 41.

Land/Lease aircrafts like hurricanes and P-40s used mainly high octane fuel supplied by allies.But there were many occasions on which they had to relay on lower grade fuels do to logistic problems.Even in areas close to source of fuel = Murmansk or Caucasus.

It is also understandable that Soviets exploited their kittyhawks and cobras way beyond healthy limit. It was a war of attrition. Question remains,if engine resurs of 3-4 days (in average 3-4h of combat sorties) was smtg acceptable in long terms.

Might be interesting to look at it from the very view of land/lease concept. You borrowed weapons from your ally and if not destroyed in combat,you were supposed to return them back after war.If you destroy/use up everything,there is nothing left to return :)

Edited by Brano

Share this post


Link to post
Share on other sites

 

 

Question remains,if engine resurs of 3-4 days (in average 3-4h of combat sorties) was smtg acceptable in long terms.

I think 3 or 4 days is maybe a little short measured. The Soviet pilots arguably only used full power against other fighters, doesn't make much sense to degrade your engine when just cruising around, or attacking bombers..and fighter v fighter dogfights on even terms definitely weren't the majority. Most sorties on all sides didn't include combat (Hartmann for example had combat - against both fighters and bombers - in only 20% of his sorties,and that at a time where the Germans already had a clear disadvantage in terms of numbers in the air). I think the combat sorties against other fighters for P40 pilots at that time weren't more then 10% of the total number of sorties (this is of course only a rough estimation by myself). In this case, the P40 engine would uphold at a high level for around one month..that's also what i read in other sources ("P40 in Soviet action" by Romanenko and Gebhardt). One month is still short, a "waste" one might say, but i guess the Soviet's could afford it, or rather had no other choice.

Share this post


Link to post
Share on other sites

In the Goldnikov interview he explains that they used speed to their advantage by 'permanently' cruising  at higher than recommended RPM and a high power setting, thus negating the known speed advantage of the Luftwaffe fighters, by being already in a 'combat ready energy state' if an enemy was encountered, and using Full rich instead of Auto rich along with maximum revs to get more speed,

 

he also notes that in combat they could use up an engine in 3-4 sorties/'battles'. Using an engine at high settings and rev's will wear it out quicker with little chance of damage so long as you keep to maximum limitations, I think max rpm on Allison was about 3100 or so, will have to check, overboosting will also expedite wear but can also lead to the risk of catastrophic damage/engine failure

 

The P-40 regiment at Stalingrad lasted operationally for two weeks of combat, before being withdrawn due to  losses and lack of serviceable aircraft.

 

I would suggest that the U.S. December 1942 limitations were unlikely used by VVS and there is more evidence (see VVS overboosting practices of Allison P-39 later in the war)  that they were operated within the limits of the Nov 1941, which is more likely the documentation supplied with the 'second hand' or even new P-40's operating in the BoS/BoM timeframe, 

 

however the November 1941 limitations seem to be slightly overly strictly enforced in some instances, and the 5 minute 56" limit of Dec 42 is a bit short in game (2.30)

 

Personally I feel we are all guilty of relying to much on the crutch of "more powerr" to save ourselves, when more consideration should be given to energy state and conservation during our sim 'dogfighting'

 

Fun fact, in a P-40 at Military power 44.2" MP you are using 100 gallons an hour more fuel than at economical cruise  :)

 

Cheers Dakpilot

 

Share this post


Link to post
Share on other sites

What's interesting is the published limits in the 1943 training manual for the P-40:

 

post-549-0-29183100-1455340410.jpg

Edited by LukeFF

Share this post


Link to post
Share on other sites

I still don't get some of these Limits, when it says 5 Minutes for settings of completely different power and wear. It seems they expected them to be ignored. They just don't make any sense. 

I would expect somethhing like:

Below 70"@3000 for 2 Minutes

Below 56"@3000 for 5 Minutes

Below 45"@3000 for 15 Minutes

Below 45"@2800 for 30 Minutes

Below 35"@2600 Continuous

 

But they give completely different Times for virtually the same Settings, for example Take Off with 45"@3000 is 5 Minutes, and it's the same even with much lower RPM.

Dec 1942 Apparently they limited quasi 45"@3000 to 5 Minutes AND 15 Minutes (1.5" difference)

 

Nothing makes sense anymore. 

Share this post


Link to post
Share on other sites

What's interesting is the published limits in the 1943 training manual for the P-40:

 

post-549-0-29183100-1455340410.jpg

Read the first pages of the manual...

 

This manual was for training pilots in the states before they moved onto the P-38/47/51 (i.e. P-40 filling the role of advanced trainer)

Edited by RoflSeal

Share this post


Link to post
Share on other sites
Read the first pages of the manual...

 

I have. :) I just wanted to share the info. That's all.  

Edited by LukeFF
  • Upvote 1

Share this post


Link to post
Share on other sites

Nothing makes sense anymore.

You need higher rpm on take off then on climb because prop efficiency is much lower at lowest speeds at normal prop rpm. So having a 5 min climb setting with lower rpm than a 5 min take off setting makes sense. It's not just about engine wear, but also performance and pilot workload.

Share this post


Link to post
Share on other sites

There is a lot of contradictory info on what the P-40 engine could achieve in 1941 or 42. Apparently the british claimed they could run the Allison at 72" in their P51As at sea level for 20 minutes in early 43, with presumably 100 octane fuel. However, there are no tests that support this claim.

 

The British did do tests of the P51A with a F.21.R Allison engine in late 42-early 43 specifically to find out how high they could boost it.

 

 

...........The level speed measurements with the F.21.R engine installed were first made using a boost limitation of 51" Hg. Measurements were made subsequently using full throttle down to ground level to determine the maximum boost and airspeeds obtainable. With the supercharger gear changed to that of the F.3.R, level speeds were measured using various boost pressures up to a maximum of 56" Hg.

 

The F.21.R was apparently very similar to the F.3.R used in the P40E.

 

However, even though they were testing to see how high they could boost it, they never went higher than 59".

 

 

....(i) Level speed measurments were made between 500 ft. and 15,000 ft. with the radiator exit duct closed (the intake scoop being sealed shut) under the following conditions and sequence.

 

...........(a) With the F.21.R (supercharger gear ratio 7.48:1), using a maximum boost of 51" Hg.
...........(b) With the F.3.R (supercharger gear ratio 8.8:1), using maximum boosts of 42, 44.5, and 56" Hg.
...........© With the F.21.R (supercharger gear ratio 7.48:1), using full throttle at all heights.

 

http://www.wwiiaircraftperformance.org/mustang/ap222.html

 

of course none of this tells us what settings the Russians were using in their P-40s in 1941-42.

Edited by Sgt_Joch

Share this post


Link to post
Share on other sites

There is a lot of contradictory info on what the P-40 engine could achieve in 1941 or 42. Apparently the british claimed they could run the Allison at 72" in their P51As at sea level for 20 minutes in early 43, with presumably 100 octane fuel. However, there are no tests that support this claim.

 

The British did do tests of the P51A with a F.21.R Allison engine in late 42-early 43 specifically to find out how high they could boost it.

 

 

The F.21.R was apparently very similar to the F.3.R used in the P40E.

 

However, even though they were testing to see how high they could boost it, they never went higher than 59".

 

 

http://www.wwiiaircraftperformance.org/mustang/ap222.html

 

of course none of this tells us what settings the Russians were using in their P-40s in 1941-42.

Agreed, we can't know for certain, but we can assume that they ran it much harder than is currently possible. I would like it restricted to the

70"+ for the current 2 Minutes as Boosted Mode Emergency Power,

56" settings for at least 5 Minutes as Emergency Mode

46"@3000 for maybe 15 Minutes as "Combat Power"

37"@2600 Continuous

And a Recoverable Setting of 44" at 2800 for 15 Minutes with Recovery of 20 Minutes. 

 

I think this is reasonable, and well within the Limitations of the Game. The Operational Limits are an incoherrent Mess because nobody really gave a Sh*t and saw them more as General Guidelines, not Strictly Enforced Limits. That's why they give the same Settings different Time Limits, Same Time Limits to completely different Settings etc. 

Edited by 6./ZG26_Klaus_Mann
  • Upvote 1

Share this post


Link to post
Share on other sites

Since the battle of stalingrad occurred during the time frame the technical note by Allison was issued (Dec 1942) it's safe to say these are the limits that should be used on the plane. It's also interesting that according to the just released dev diary, the P-40 has the following engine limits:
 
Engine modes:
Nominal (unlimited time): 2600 RPM, 37.2 дюйм рт.ст.
Combat power (up to 5 minutes): 3000 RPM, 42 дюйм рт.ст.
Take-off power (up to 5 minutes): 3000 RPM, 45.5 дюйм рт.ст

 

This doesn't even match the November 1941 notes.

 

Also, while the thread is on engine performance, I'm curious about the listed turning performance in the dev diary. Is there a good way to check to see if the listed values below are accurate?

 

Maximum performance turn at sea level: 30.9 s
Maximum performance turn at 3000 m: 36.3 s

Share this post


Link to post
Share on other sites

 

Since the battle of stalingrad occurred during the time frame the technical note by Allison was issued (Dec 1942) it's safe to say these are the limits that should be used on the plane. It's also interesting that according to the just released dev diary, the P-40 has the following engine limits:

 

Engine modes:

Nominal (unlimited time): 2600 RPM, 37.2 дюйм рт.ст.

Combat power (up to 5 minutes): 3000 RPM, 42 дюйм рт.ст.

Take-off power (up to 5 minutes): 3000 RPM, 45.5 дюйм рт.ст

 

This doesn't even match the November 1941 notes.

 

Also, while the thread is on engine performance, I'm curious about the listed turning performance in the dev diary. Is there a good way to check to see if the listed values below are accurate?

 

Maximum performance turn at sea level: 30.9 s
Maximum performance turn at 3000 m: 36.3 s

 

I never managed above 27 Seconds, mostly 29 ingame. 72 inches achieve 19 Seconds. 

Share this post


Link to post
Share on other sites

Maybe they were testing at nominal power. As Klaus_Mann already said, engine power makes a huge difference.

Share this post


Link to post
Share on other sites

Hmm, then perhaps the apparently-quite-incorrect engine settings are showing up in other areas that I hadn't considered. At any rate, I don't know what else you can go on other than the actual manufacturer's suggested settings, which are clear.

Share this post


Link to post
Share on other sites

Strongly agree.

 

As testified by Golodnikov, the Soviets probably ran their engines at the top end of what the Sim calls 'combat power' the entire time they were in the combat area - and burned them out in 3 or 4 missions. In peace time that is unacceptable, and in war time it would be logistically unsustainable...but it is still a different thing to seizing up in a matter of minutes the way it does in game.

 

Even though every mission starts with a new engine, I think it would be bad from a 'game play' standpoint to allow players to run at high combat power all the time. If it were up to me, I'd implement the limits suggested by Klaus_Mann above. If the 'recoverable' part is too complicated, at least implement the rest of his limits. That way the P-40 would be able to perform closer to the level of performance that the Soviets obtained, but pilots would not be able to derp around at full WEP all the time like in War Thunder.

 

The current situation is kind of sad - the Devs put all this work into crafting a SUPERB P-40 model but people aren't flying it much because they can't make it compete historically the way the Soviets could. (I got shot down on the Berloga dogfight server yesterday by a teammate...told me he hadn't seen a P-40 in so long that he thought I was a German.)

 

Thanks for reading.

The He-111 and Ju-87 have recoverable Take-Off Settings that regenerate after 10 Minutes or so, and I think the F-2s Emergency Power does as well after 20. 

The feature exists and it's not more than a single added line and would offer us a useful Climb Setting.

 

I think that all 5 Minutes or Less Settings should recover after no more than 30 Minutes. 

Edited by 6./ZG26_Klaus_Mann

Share this post


Link to post
Share on other sites

c'est la vie 

 

1-1.JPG1-2.JPG1-3.JPG

2-1.JPG

3-1.JPG3-2.JPG

4-1.JPG4-2.JPG

  • Upvote 4

Share this post


Link to post
Share on other sites

What I found interesting with those documents Han posted is that (1) the Soviet manual is just as conservative as the early American ones and (2) that the "Flight Operation Instruction Chart" (10 April 1943) has more conservative values for Military Power than that seen in the earlier chart from 18 December 1942. 

Share this post


Link to post
Share on other sites

What I found interesting with those documents Han posted is that (1) the Soviet manual is just as conservative as the early American ones and (2) that the "Flight Operation Instruction Chart" (10 April 1943) has more conservative values for Military Power than that seen in the earlier chart from 18 December 1942. 

The soviet manual may have just been a direct translation of what Allison gave them and P-40E were being withdrawn from front line service through 1943, either replaced with newer variants, or P-38, Spitfire etc.

 

Thing is ingame, 44.5" at 3000rpm is classed as "War emergency Power" where no document classifies it as this.

  • Upvote 1

Share this post


Link to post
Share on other sites

 

 

But what about these that specify a War Emergency Power setting rather along with Military or Take-off

 

Does not really matter.  The VVS published their own manual on their own purchased equipment:

 

It is not a captured aircraft so the maintenance personnel are not being asked to play detective in order to figure out how the machine is operated.  The VVS is being provided the operating instructions from the manufacturer.

 

The 5 minute rating corresponds to the published limits.

 

2z8rzpl.jpg 

 

 

 

Thing is ingame, 44.5" at 3000rpm is classed as "War emergency Power" where no document classifies it as this.

 

 

It seems it should be 45.5" and is a take off rating.  

 

That means restricted to take off use only.  Notice in the instructions do not allow for it to be used over 2600 feet Density altitude.

 

kf5kpi.jpg

 

 

 

What I found interesting with those documents Han posted is that (1) the Soviet manual is just as conservative as the early American ones and (2) that the "Flight Operation Instruction Chart" (10 April 1943) has more conservative values for Military Power than that seen in the earlier chart from 18 December 1942. 

 

Yep.....

 

Lots of fantasy and misconceptions about aviation convention and how aircraft are operated....

 

 

 

 

he Soviets probably ran their engines at the top end of what the Sim calls 'combat power' the entire time they were in the combat area -

 

 

 

 

As testified by Golodnikov,
 

 

I am betting somebody misunderstood or took something out of context which then gets turned into fact because of the misconceptions of how airplanes work and are maintained.

  • Upvote 1

Share this post


Link to post
Share on other sites

 

 

 

 

I am betting somebody misunderstood or took something out of context which then gets turned into fact because of the misconceptions of how airplanes work and are maintained.

Golodnikov said they were using max RPM and higher power settings whilst cruising so as to enter combat at high speeds, and subsequently trashing the engines on the P-39/40 in 3-5 missions, he called the P-39 a dud had they been using the engine regimes in the manual.

 

Allison were overconservative with the engines until 1944 P-38L, probably the most documented being Ben Kelsey abuse testing on the P-38Gs engines and establishing an absolute CAT limit of 90 degrees C, twice as much as Allisons figure and run much higher power settings above 50 degrees for 7-8 minutes safely without engine deterioration.

Edited by RoflSeal

Share this post


Link to post
Share on other sites

 

 

Allison were overconservative

 

I think Allison published the limitations that met the same statistical and engineering parameters that everyone adhered too.

 

 

 

 

subsequently trashing the engines on the P-39/40 in 3-5 missions
 

 

I do not see anyone being over conservative even in the anecdotal evidence.


I am sure that I am a first class A__H___ to some people for pointing this out...

 

That is really not the case.  It is just the engineering limitations of flight and complies with aviation convention.


At the attrition rate of replacing aircraft engines in 3-5 missions, who needs an enemy to fight?  At that rate, it will not take long for the unit to be so understrength as to be combat ineffective.

Share this post


Link to post
Share on other sites

I think Allison published the limitations that met the same statistical and engineering parameters that everyone adhered too.

 

 

 

 

 

 

Like 5 minute military power? When every other manufacturer (Packard, RR, DB, etc) had military/combat power of 15-30minutes and Klimov didn't even engine time limits since they could support a high replacement rate.

Edited by RoflSeal

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.

×
×
  • Create New...