The Fw-190A8 Thread

[SCG_Fenris_Wolf]

Asgar is right on his last point, even if he's a bit too fired up.

 

Guys, we are here to discuss based on sources, etc. If someone challenges your claim, you ought to present them. Without acting like a child "hah, I told u so!!1". That would be inflammatory, just a little precautionary warning.

 

Now let's stay on topic, which is the A8 and its possibilities

 

The sources presented so far were indeed interesting and I'm hopeful the plane will be properly implemented.

 

With bane I am looking at IL-2's (less simulated) competitors and how they made it a flying brick. The Jäger with Schlachtflugzeug weight, but not the armor, and much less than the expected 10minutes emergency power... Face-palm.

Edited January 23, 2018 by SCG_Fenris_Wolf

[JV69badatflyski]

i'd like to correct some info, as it seems getting old works heavily on the memory and the info stored 10years ago...
 

All A-8 were delivered with the ETC501, secondary fuel tank in the back and weights on the propeller. >> Nope, looks like several initial batches were delivered without the rear fueltank

The weights acted as counter weight to get the CoG right, just as the displacement of the ETC 15cm forward, because of the new fueltank at the back.

A-8 used 1.65 ata standard in both supercharger stages. Some FW official records mention the use of 1.98Ata by the JG2 and JG300 , showing no special engine damage.(just anecdotal as we'll never get this anyway) and other reports showing planes being delivered with 1.8Ata .

https://drive.google.com/open?id=1ESKtes8yOYGtXEAJglptBkn6YAKFsJXP ( Lord Efe: please confirm if my comprehension of german is still ok, danke )

 

Never used MK103 in Pods as it wrapped the longeron.->still has to find the RLM report on this on my old hdd

Never used GM-1 or MW-50, just been tested. The use of it would be stupid as the same power output could be achieved by overpressure. it wasn't simply worth of flying with dead weight.

https://drive.google.com/open?id=1k1iNlXZF3Vy35b_UwkgJHK_9f4CM25Ge (same page as provided by Jtd)


The 801 used from end43 on FW's wasn't the same as before, as it received parts from the abandoned 801F E(pistons, rods, valves and other stuff i don't remember, should have this at home) allowing higher compression and load.

Copy of text from LEMB or Whiteonefundation, don't really remember, dated on my hdd  from 08sept2008. It converge with the german text above:

https://drive.google.com/open?id=1Ft9IlsWbGV33AGhT7wiDoHpL7elB8dVl

Lord Efe: thanks for the small correction, being a very lazy writer,i go straight to point and like you can see, memory isn't that good anymore
 

Just info: also something very old, think from LEMB:
801 boost evolution:
https://drive.google.com/open?id=16Y9pX2UPDudMtxBpHCgSmPDyYVALITZd
 

Edited January 23, 2018 by JV69badatflyski

[CUJO_1970]

why [Edited] should i BEFORE any source is presented, if i have a source that says otherwise?

 

Because you look silly and uninformed, while questioning guys that have been around this genre for many years before your time and have forgotten more than you know about this subject.

[I./JG62_Lord_Efe]

Who of us is not a lazy writer, thats why were "Pilots"   but...

 

https://drive.google...lptBkn6YAKFsJXP is read in my interpretation in the following way: 

"A post flight inspection revealed that there was a 10mm crack at cylinder 14. The crack proceeded between the two spark plug housings towards the injection nozzles an divided the cylinder head into a half. While checking emergency power, ÄA133 (no idea what that means), it was discovered that 2 screw - something one  1,8mm and 2mm ( i can't find a translation for that, aperture like things to regulate the air intake to the cylinder itself) were missing, instead there was a normal connector piece with a 4mm drilling. As a result of the bigger drilling the air intake was so high that manifold pressure reached 1,8 ata. 

On 4 more planes of this unit, on cylinders 8, 11, 12 and 14 cracks occurred. For changing the cylinders the Aircrafts were designated to the manufacturer. In flight testing was not possible due to fuel shortages and enemy activities in the area." 

 

So 1.8ata was not wanted, was more likely a production error or sabotage 

 

Edit 1:

BTW: Guys lets just, add our sources, so there is no " i don't believe it"   and we even can compare source 

Edit 2: Emergency power is only limited to 10 minutes due to thermal reasons

Edited January 24, 2018 by [I./JG62]Lord_Efe

[Asgar]

Because you look silly and uninformed, while questioning guys that have been around this genre for many years before your time and have forgotten more than you know about this subject.

only one here who looks silly is you. seriously, if you have nothing to add to the discussion just crawl back into your basement and keep your mouth shut

[GP*]

Lots of great info (and lots of reading for me to do) on this subject...let's not get this thread locked on page 2!

[SCG_Fenris_Wolf]

Asgar, calm, we are aware of it, also that he didn't bring anything to the discussion but provocative behavior. Just ignore him - don't feed the troll. His name is "ass" in Spanish. Nomen est omen. Just report him and wait for the mods to sort it out.

Edited January 24, 2018 by SCG_Fenris_Wolf

[JtD]

The fighter (Jäger, C)

1.42ata continuous combat power.

Emergency 10minutes, 1.58 ata gear 1 / 1.65 ata gear 2. Without needing any tricks, impressive indeed.

The GM3 I was for higher than 8km and could be flown for 20minutes. "Fitted by factory as often as available".

 

The Schlachtflugzeug (B), aka Butcher Bird, shares with the ground attack version G8 (A), both had C3 injection: Giving them 1.65ata for gear 1. 3x10minutes, 10 minutes cooldown inbetween (cooldown at full combat power 1.42 ata).

1.42ata is not continuous. Where did you find that? The engine operating limits weren't changed except for the addition of the various special emergency modes, 1.42 still being WEP.

But flying the fighter at 1.58/1.65ata for 10 minutes is going to make quite a difference. Compared to the 1.32 ata of combat power, you add another 300hp-400hp. About 25%, depending on altitude. That's something you'll definitely feel. The Fw190A8 is going to be more than 10% heaver than the A-3, which you'll also feel. However, quite a bit of that extra weight is due to extra fuel, weapons and ammo, so it might be worth it.

 

p.s. I hope we'll get improved engine damage models, because the idea of blowing your engine after 3 minutes at 1.42ata but only after 10 minutes at 1.65ata is looking very odd.

Edited January 24, 2018 by JtD

[Eicio]

If I remember well the A8 has 4*mg151/20 and it surely isn't nothing, it makes it more armed than the D9. Overall I don't know if it'll be a real danger for the allies but they'd better not let him have a shot on them.

[Mac_Messer]

Sadly (or not), the relative performance is where it`s at. And with the Anton A8, you`re not competing against the Hurricane/Tchaika anymore. The more maneuverable types of pilots will be sorely hurting in this plane. Nice target for the Jugs and Ponys to shoot at.

[Sgt_Joch]

p.s. I hope we'll get improved engine damage models, because the idea of blowing your engine after 3 minutes at 1.42ata but only after 10 minutes at 1.65ata is looking very odd.

 

not if you understand how C3 works, which I am sure you do, but for those who don't.

 

C3, MW50, water injection, etc. all work on the same basic principle. You inject a liquid with anti-detonation properties into the cylinder which cools the air-fuel mixture and allows you to run the engine at a higher effective compression ratio without running the risk of premature detonation which can damage the engine.

 

Even then, the C3 operating instructions made it clear that the pilot had to keep the engine temperature below a certain maximum, again to prevent the risk of detonation, so it is not as if you get a garanteed 10 minutes.

 

so C3 was most effective and useful if you were flying in a straight line trying to achieve maximum speed, less effective if the plane is used in tight turns where engine temperatures would tend to rise more quickly.

 

p.s. - I would be surprised if we do not get a more realistic engine damage model with "Bodenplatte" since the WEP time limits is an issue which will affect planes on both sides.

Edited January 24, 2018 by Sgt_Joch

[=RvE=Windmills]

Sadly (or not), the relative performance is where it`s at. And with the Anton A8, you`re not competing against the Hurricane/Tchaika anymore. The more maneuverable types of pilots will be sorely hurting in this plane. Nice target for the Jugs and Ponys to shoot at.

 

You would rather dogfight a Yak1 over a P47 when flying a 190?

 

Unless every other representation of the P47 in sims was sorely mistaken I don't think I'd make the same choice here.

[Mac_Messer]

You would rather dogfight a Yak1 over a P47 when flying a 190?

 

Unless every other representation of the P47 in sims was sorely mistaken I don't think I'd make the same choice here.

That`s the whole point - the Anton A8 is so heavy (underpowered?) that even the P47/P51 will eat it alive. Because in A8 you can`t turn at all, whereas in P47/P51 it`s worth the risk.

 

So....yes, I`d take the Yak1 as enemy any day in A8, probably because most of the times I`d be able to run away or to bail out safely. Now you end up on the bad side of the fifties, you`re done for.

[ShamrockOneFive]

That`s the whole point - the Anton A8 is so heavy (underpowered?) that even the P47/P51 will eat it alive. Because in A8 you can`t turn at all, whereas in P47/P51 it`s worth the risk.

 

So....yes, I`d take the Yak1 as enemy any day in A8, probably because most of the times I`d be able to run away or to bail out safely. Now you end up on the bad side of the fifties, you`re done for.

 

Doesn't the power increase on the A-8 offset the added weight? In particular if some of the weight is expendable like fuel and ammo stores...

[JtD]

C3, MW50, water injection, etc. all work on the same basic principle. You inject a liquid with anti-detonation properties into the cylinder which cools the air-fuel mixture and allows you to run the engine at a higher effective compression ratio without running the risk of premature detonation which can damage the engine.

To be exact, C3 injection is not an anti detonant, it is just more of the same fuel. It was only done because the fuel pump on the BMW801 was insufficient to deliver the fuel thought necessary at the increased boost. Rich mixtures burn at lower temperatures than lean mixtures, so you have a good interest in providing the necessary fuel. C3 was injected into the intake, and this way contributed somewhat to charge cooling, too, but the main point was to provide the fuel for a sufficiently rich mixture.

 

However, during testing it was found that on some aircraft the injection had not worked, and engine temperatures did not exceed the limits, so the system was simplified and boost was increased at the leaner mixture with no addition of any extra fuel or anti-detonant.

 

Pilots where indeed advised to use the systems with care, given that on a hot summer day, with continued use of the erhöhte Notleistung in a climb, oil temperatures would approach the permitted maximum.

[Mac_Messer]

Doesn't the power increase on the A-8 offset the added weight? In particular if some of the weight is expendable like fuel and ammo stores...

Yeah but it`s just one of the factors influencing plane handling (in this case, maneuverability, energy bleeding at moderate and high speeds). If we got the A9 with even better engine and wooden propeller, I might change my mind.

[Sgt_Joch]

To be exact, C3 injection is not an anti detonant, it is just more of the same fuel. It was only done because the fuel pump on the BMW801 was insufficient to deliver the fuel thought necessary at the increased boost. Rich mixtures burn at lower temperatures than lean mixtures, so you have a good interest in providing the necessary fuel. C3 was injected into the intake, and this way contributed somewhat to charge cooling, too, but the main point was to provide the fuel for a sufficiently rich mixture.

 

However, during testing it was found that on some aircraft the injection had not worked, and engine temperatures did not exceed the limits, so the system was simplified and boost was increased at the leaner mixture with no addition of any extra fuel or anti-detonant.

 

Pilots where indeed advised to use the systems with care, given that on a hot summer day, with continued use of the erhöhte Notleistung in a climb, oil temperatures would approach the permitted maximum.

 

so you do know how it works!   

 

However, if you want to be really exact, the C3 injection was not designed to deliver more fuel to the engine, since a good chunk of the injected fuel would not ignite and just be wasted.

 

It played on the fact that if you push the fuel:air ratio high enough, you retard the point at which the mixture would ignite allowing you to run at a higher boost, albeit at a cost of wasting fuel. In effect, it works as a super-super rich mixture setting. So the extra fuel was being used for its anti-detonation properties. 

Edited January 24, 2018 by Sgt_Joch

[JtD]

According to German test reports it was used to reduce oil temperature and the risk of pre-ignition due to overheating spark plugs. Both are the effects of burning leaner mixtures, which produce higher temperatures. Neither oil temperature nor pre-ignition is detonation, i.e. self ignition of the fuel air mix due to too high charge temperatures. I'll go with what the German engineers say (my technical knowledge comes to the same conclusion, so little choice here). But we don't have to agree.

 

At 1.42ata the specific fuel consumption was 300g/PSh, at 1.6 without C3 injection, it was 280g/PSh. Limited by the fuel pump. C3 injection added 20g/PSh so that 1.6ata would not burn at a leaner mixture than 1.42ata.

[Sgt_Joch]

well "pre-ignition" IS what leads to "detonation", as we use it in discussions around here anyway, so we are saying basically the same thing.

 

but we are getting way off-topic, I don't believe there is any disagreement on why C3 injection allowed the 190 to run at a higher boost.

Edited January 24, 2018 by Sgt_Joch

[JtD]

Which doesn't matter for the A-8 because it doesn't have C3 injection, but erhöhte Notleistung instead.

[MiloMorai]

It is to bad the younger generation has to be spoon fed.

 

translation required as in German, http://www.deutscheluftwaffe.com/archiv/Dokumente/web/new%20site/frames2/Dokumente.htm

 

Author, Dietmar Hermann 

[Sgt_Joch]

Which doesn't matter for the A-8 because it doesn't have C3 injection, but erhöhte Notleistung instead.

 

which is the same thing is it not? or are you saying there is a technical distinction between the two systems.

[JtD]

It is not the same thing, like I've said in post #23.

 

They share the principle, i.e. venting the boost control chamber of the Kommandogerät into the atmosphere tricking the KG into believing there's lower boost than there actually is.

 

They do not share the venting parameters, erhöhte Notleistung is using smaller diameter venting holes for less venting, so that the change in boost is smaller than with C3 injection (1.58 vs. 1.65 in low charger gear). This is done to permit operation also in second charger gear, where the resulting boost is 1.65. Engaging C3 injection in high blower would lead to higher boosts than 1.65, which were not considered/tested/cleared.

 

Also, and more importantly, only the C3 injection system does inject extra fuel (into the left air intake). Erhöhte Notleistung doesn't. It just tricks the Kommandogerät into overboosting and that's it.

 

Attached the snippet from the A-8 manual, 'ohne' meaning 'without'.

 

Operationally, C3 injection was used on fighter bombers and attack versions (F&G models), but not on fighters (A models).

Edited January 24, 2018 by JtD

[GP*]

It is to bad the younger generation has to be spoon fed.

 

And what is that in reference to?

[Jaws2002]

the Anton A8 is so heavy (underpowered?) that even the P47/P51 will eat it alive.

And what exactly do you base this statement on?

 

Do you realize the pure fighter FW-190 A8 has pretty much the same thrust to weight ratio with the Bf-109 G2?

[Sgt_Joch]

It is not the same thing, like I've said in post #23.

 

They share the principle, i.e. venting the boost control chamber of the Kommandogerät into the atmosphere tricking the KG into believing there's lower boost than there actually is.

 

They do not share the venting parameters, erhöhte Notleistung is using smaller diameter venting holes for less venting, so that the change in boost is smaller than with C3 injection (1.58 vs. 1.65 in low charger gear). This is done to permit operation also in second charger gear, where the resulting boost is 1.65. Engaging C3 injection in high blower would lead to higher boosts than 1.65, which were not considered/tested/cleared.

 

Also, and more importantly, only the C3 injection system does inject extra fuel (into the left air intake). Erhöhte Notleistung doesn't. It just tricks the Kommandogerät into overboosting and that's it.

 

Attached the snippet from the A-8 manual, 'ohne' meaning 'without'.bla000.jpg

 

Operationally, C3 injection was used on fighter bombers and attack versions (F&G models), but not on fighters (A models).

 

with all due respect, that explanation seems to have a huge technical gap. If they could just increase the boost to 1.65 with no other changes in the parameters, there is no reason why you can run 1.65 for 10 minutes, but be limited to 3 minutes at 1.42.

 

If you dig down into the detailed technical explanation of the "Kommandogerat", you will most likely find that it was using a very rich mixture setting which had the same practical effect as C3 injection.

[JtD]

there is no reason why you can run 1.65 for 10 minutes, but be limited to 3 minutes at 1.42

Exactly. Which is why I consider it wrong to defend the gaming mechanism we currently have as realistic. It's ink on paper, and that's it.

 

And no, the Kommandogerät did not have a super rich setting beyond the super rich it used for 1.42ata already. Like I've said before, the fuel pump was the limit and that was not changed.

[Sgt_Joch]

ok, I think I found it. 

 

FW190A8 flight report on the use of 1.65 boost:

 

 

 

  At the instigation of the EZA it was to investigate, which speed increase and which time to climb decrease for emergency power can be obtained by the means of an increase in boost on the BMW 801 D in the Fw 190 A 8 (fighter). The boost was to be adjusted to 1.65 ata for the second supercharger gear by the means of blinds in the air lines on the mixture and boost regulator in the same way it is done with the C 3-injection for fighter bombers (see report Nr. 640/43). As a testbed, a Fw 190 A-5 of the test commando 28 - white 35 - was provided.

 

At first flights for tuning the blinds in the intake air lines at the mixture regulator and at the boost regulator were done.  A boost of 1.65 ata was to be reached after switching to second charger gear, which was accomplished by a blind of 1.5 x 2.0 Ø at the mixture regulator and 1,5 x 1,8 Ø at the boost regulator.

 

http://www.wwiiaircraftperformance.org/fw190/BMW-VB-126.html

 

again someone would have to check the German to see if the translation is accurate, but you can see how they adjusted the mixture regulator to get the same effect as c3 injection.

 

if I read this correctly, they were restricting the air intake, which, if the fuel flow stayed the same, would have the effect of boosting the fuel:air mixture ratio and producing a very rich mixture setting.

Edited January 24, 2018 by Sgt_Joch

[Mac_Messer]

And what exactly do you base this statement on?

 

FW190A8 performance in vanilla IL2:1946.

[rolikiraly]

Great stuff guys! It's interesting to read your posts, as i know a little bit about internal combustion engines in general, but not nearly all these details about the BMW801.

 

I for one really hope that the aircraft will be at least somewhat competitive/comparable to its main adversaries. I honestly think it's mainly the numbers and the pilots/tactics that made the huge difference late in the war, but correct me if I'm wrong. Anyway, we will see how it turns out and which modifications are included, and it might not be that far away actually (for those who preordered). I would guess it'll be one of the first planes released for Bodenplatte.

 

Also i'm surprised that no one mentioned the windscreen   . After all there are two more FW-190s coming.

Edited January 25, 2018 by rolikiraly

[JtD]

but you can see how they adjusted the mixture regulator to get the same effect as c3 injection

 

Certainly the mixture chamber (which with both systems had to be vented in order to stay inside operating parameters) was manipulated so that magically the friggin injection pump grew larger - oh wait, it didn't, even the report you linked clearly shows the total capacity is still 550kg (~725l) per hour. Not the 800l used in the C3 injection.

Edited January 24, 2018 by JtD

[Sgt_Joch]

 

Certainly the mixture chamber (which with both systems had to be vented in order to stay inside operating parameters) was manipulated so that magically the friggin injection pump grew larger - oh wait, it didn't, even the report you linked clearly shows the total capacity is still 550kg (~725l) per hour. Not the 800l used in the C3 injection.

 

again, sometimes I think you are only interested in scoring points rather than figuring out how things work.

 

what exactly do you think the result is if you restrict air flow, but leave the fuel flow exactly the same which is what the report says.

 

​why don't you actually read the report.

 

your explanation that they would just increase the boost with no other changes made no technical sense. As I suspected and the report seems to bear it out, they manipulated the mixture regulator to produce a very high mixture setting which would have the same practical effect as C3 injection, namely retarding the onset of pre ignition/detonation, but with all the disadvantages of running a very high mixture setting.

Edited January 24, 2018 by Sgt_Joch

[JtD]

sometimes I think you are only interested in scoring points rather than figuring out how things work

I'm not figuring anything out, I KNOW how it works. And if you instead of bringing up one odd theory after the other simply stated what you don't get and asked for an explanation, this would have been dealt with in two posts instead of twenty.

 

what exactly do you think the result is if you restrict air flow, but leave the fuel flow exactly the same which is what the report says

No, it doesn't say that. Because if you restricted air flow, you'd reduce boost. They are venting control chambers of the Kommandogerät, they are not restricting anything in air or fuel flow. In fact, as a net effect of the venting, the Kommandogerät is increasing both.

 

why don't you actually read the report.

Looks like I made the translation. Guess that means I read it years ago.

 

your explanation that they would just increase the boost with no other changes made no technical sense. As I suspected and the report seems to bear it out, they manipulated the mixture regulator to produce a very high mixture setting which would have the same practical effect as C3 injection, namely retarding the onset of pre ignition/detonation, but with all the disadvantages of running a very high mixture setting.

Whatever, believe what you like. I'm positive that everybody else will understand that manipulating a mixture regulator will not increase the capacity of the limiting injection pump.

[CUJO_1970]

only one here who looks silly is you. seriously, if you have nothing to add to the discussion just crawl back into your basement and keep your mouth shut

 

How can you be a tester if you don't know anything?

 

Asking for a friend.

[CUJO_1970]

FW190A8 performance in vanilla IL2:1946.

 

IL/2 was great in it's day, but it had some real warts too.

 

The real life power loading for the late 8/9 series Antons was actually pretty good - they were commented on as being the most maneuverable and best handling of the series by guys like Addi Glunz and Pips Priller.

[CUJO_1970]

If I remember well the A8 has 4*mg151/20 and it surely isn't nothing, it makes it more armed than the D9. Overall I don't know if it'll be a real danger for the allies but they'd better not let him have a shot on them.

 

Yes, these became available with the A-6 wing redesign in 1943. It has the advantage of standard and heavier weapons so you have same velocity and trajectory to work with. Right now with A3/5 you have three different gun types firing different trajectory and velocity.

 

A8/9 also has the heavier MG/131 in the nose replacing the old MG/17. It was a devastatingly heavy hitting aircraft.

 

New wing also can carry MK-108 outboard canons, first tested (but not serially produced) on A-6.

[JV69badatflyski]

It is to bad the younger generation has to be spoon fed.

 

translation required as in German, http://www.deutscheluftwaffe.com/archiv/Dokumente/web/new%20site/frames2/Dokumente.htm

 

Author, Dietmar Hermann 

+190 For once i sooooo agree with you

 

like to repeat my self, but that's the privilege of getting old:

Copy of a text from LEMB or Whiteonefundation from 2008 (None of both sources can be argued with, Lemb Being the WW2 airplanes books writers forum, the second rebuilding an F-8 with original 801 and access to factory data.)

 

increasing Knock Limited Performance in the BMW801D2

Part 1

Throughout the war, the BMW801D2 was continually developed to keep pace with the performance

of the allied fighters faced by the FW-190 equipped Geschwaders. The engine became a

reliable workhorse and made the FW-190 one of the best performing low altitude fighters of

the war. It began its design lifecycle with a top shaft output of 1670PS at Start u Notleistung

at 1st Gear supercharger full throttle height and gained 150 PS by wars end at the same settings.

Additional boost systems raised this power output to over 2100PS. The BMW801D2 was developed

to the limits of its potential and even beyond a point when other motors such as the BMW802

showed greater promise for a similar effort. The Achilles heel however continued to be high

altitude performance. This article in two parts will discuss the 4 major systems used to increase

knock-limited performance in the BMW801D2 above the engines normal Start u Notleistung rating.

 

<POH maintenance schedule for BMW801C motors>

<POH maintenance schedule for late war BMW801D2>

 

In June of 1942 BMW completed a theoretical investigation in the potential development of the motor.

Without any major change to the motor it was possible to increase shaft power output at full

throttle height by 40PS at Start u Notleistung and 110PS at Steig u Kampfleistung. With some major

changes it was possible to get a shaft output of 2000PS without additional knock limiting performance

enhancements. It was determined that the motor had the potential for developing between 2000PS-2200PS

by injection of knock limiting agents such as water or alcohol water mixtures. Work began immediately

on putting the theory into practice. Prototype motors were constructed and work began on improving the

power output of the motor at all levels. By July 1942 BMW had constructed several prototype motors to

begin laboratory bench testing. BMW801D2V15 achieved 1950PS shaft output without ram or knock limiting

performance enhancements during this phase. In the quest for attaining the full potential of the BMW801D2

three knock limiting agent injection systems and one method of oxygen enrichment of the charge were shown

to be practical or worthy of further investigation.

 

<Insert Picture 1 BMW801D2V15 ram power production>

 

C3-Einspritzung, The Bomber and Attack Pilots Insurance

The first system to see operational adoption was the injection of C3 fuel as a knock limiting agent

directly into the left side of the supercharger intake. Motors were modified with stronger pistons

adopted from the BMW801E/S development. These new pistons became the production standard on all BMW801D

series motors in June 1943.

 

<new Pistons>

 

On the 10th of April 1943 the first flight testing of the new system began with a 25-minute flight in the low

altitude portion of the 1st gear supercharger and resulted in 8 minutes of the systems use. By the 22nd of

April 1943 test flights were using the system as long as 15 minutes and at manifold pressures as high as 1.8ata

between 3.5km and 7km altitude. Initial flight-testing was completed on the 17th of May 1943. The flight test

results concluded however that the system produced 2050PS in the 1st Gear Supercharger and that a manifold pressure

of 1.65ata could be used reliably. As the pressure fell off with altitude however, the standard fuel pump was not

able to provide sufficient quantities of fuel to allow the system to develop additional power in the 2nd Gear

Supercharger. The engine cooling was also not sufficient enough for the system to be used in climbing flight.

The fuel pump could not deliver enough fuel to the left hand supercharger intake to keep cylinder temperatures

within operational limits at climbing speeds. It was felt that a further 50PS of thrust power could be gained

by changing the propeller reduction gearing to a more suitable ratio in order to fully exploit the new power

gains of the motor. The initial testing was completed and the findings compiled by the 19th of July 1943.

It is interesting to note that JG54 begins reporting experience with the new system in 23 July 1943.

This point’s to JG54 conducting operational testing of the system shortly after the completion of the initial

testing and during the endurance trials.

That same month endurance testing began on the new system. Five test aircraft were selected. Three fighter variants

and two fighter-bomber variants were selected with a mix of cooling gill types for the testing. One aircraft,

an FW-190A4 SB+IK was selected to use Methanol Water as a knock limiting injection agent for a total of 4hrs 43

minutes flight time. The aircraft switched back to C3-Einspritzung for the remainder of the testing. A spark plug

change was recommended to the Bosch DW 240 ET 7/1a on all aircraft using C3-Einspritzung.

By August 1943 the RLM was comfortable enough with the reliability and performance increase of the new system to issue

instructions for it’s use in the September 1943 FW-190A4 Flugzeug-Handbuch Teil 07 for Ground attack variants of

the FW-190 series at altitudes of 1 Km and below. The Flugzeug-Handbuch also notes that the system can be retrofitted

onto earlier variants. This required swapping the entire Triebwerk or power egg, as the system required the internal

changes adopted in June 1943 for all serial production BMW801D2’s. The system was limited to one 10-15 minutes use and

the pilot was instructed to watch his oil temperature not allowing it to go over 85 degrees Celsius. During the

testing the oil temperature remained between 70-77 degrees Celsius with the system in use. Fuel consumption was an

average of 70 liters per 5 minutes time flown with C3-Einspritzung.

To overcome the voracious appetite for fuel, Focke Wulf investigated the installation of a 115 liter

zustatzkraftstoffbehältor im rumpf mounted inside the fuselage behind the cockpit. It was found that the tank caused

the CG to move dangerously rearward and made the aircraft unstable. In order to restore the CG, weights were added

to the propeller roots on aircraft using the zustatzkraftstoffbehältor im rumpf. Making the aircraft safe to fly

with this tank would become a stumbling block for Focke Wulf, Gmbh. Mounting the tank on fighter variants became an

issue with RLM in December 1943 and delayed the introduction of the FW-190A8. The ETC 501 rack was moved forward

to restore the CG in serial production FW-190A8, a fill port, and an access hatch was also provided in the fuselage.

The tank installation would not find serial production introduction until the August -September 1944 timeframe

on any BMW801D2 powered variant. This installation can be noted by the presence of C3 warning triangle at the fill

port which must be marked and the presence of the propeller weights. In Geschwaders equipped with the FW190A8 the

tank could be ordered as a separate piece of equipment before its introduction in serial production in October 1944.

The balance issue was eliminated in the FW190A9 by the installation of thicker armor on the oil cooler.

The tanks operational use was limited to aircraft modified by the factory with a special kit in the earlier bomber

and ground attack variants.

 

<propeller weights VDM ersatzteilliste>

<tank installation digram>

 

The next development for C3-Einspritzung occurs after the completion of the endurance testing.

The limits are raised to “as long as the emergency lasts” in the December 1943 FW-190A5 Flugzeug-Handbuch,

Teil 07. During 1943 however, an alarming number of BMW801D2 motors experienced connecting rod failures.

It was not until mid-1944 that the cause was discovered to be a change in the oil formulation that caused

the oil to break down at lower temperatures than expected under stress and heat. These events must have had

an influence on the limitations of C3-Einspritzung. In March 1944 Focke Wulf reissues instructions for the

use of C3-Einspritzung limiting the system to three uses of 10 minutes each with a mandatory 10 minutes cool

down period at Stieg u Kampfleistung or 1.32ata at 2400U/min.

These instructions are reprinted in the February 1944 Flugzeug-Handbuch, Teil 07. By July of 1944 further

instructions are issued stating the system can be used for 10-minutes only.

C3-Einspritzung raised the performance of the FW-190 ground attack variants at altitudes below 1 KM adding an

average speed increase of 35-40kph. This put the Ground Attack variants in the 565kph to 595kph range without

mounted ordinance and depending on the type of wing rack installed on the aircraft. This also put the FW-190

ground attack variants with ordinance racks on equal or slightly superior footing in level speed with most

allied fighters in a clean configuration. On the Eastern Front it was not until the VVS began to acquire in

early 1945 variants of the La7 capable of achieving 612kph using augmented power of the Ash-82FN that they

possessed a fighter capable of intercepting FW-190 ground attack variants below 1km.

 

<Gordan and Khazonov, Soviet Combat

Aircraft of the Second World War. Volume One – Single Engine Fighers>

<C-3 POH picture>

<C3 diagram>

<FW190 performance with C3>

 

Without a doubt C3 Einspritzung contributed greatly to the Schlachtflieger and Bombenflieger survival in combat.

 

Ladedruckerhöhung, Keine C3-Einspritzung!

 

Due to the fact C3-Einspritzung power production fell off after 1 KM in altitude it was quickly realized that an

alternative would have to be developed for use by the Jadgeschwaders. C3-Einspritzung delivered spectacular

performance but the low altitude restrictions made it unsuitable for normal fighter operations.

Erprobungskommando 25 was selected to begin testing of a new system.

 

http://www.ww2.dk/air/jagd/ekdo25.htm

http://www.ww2.dk/oob/bestand/jagd/bekdo25.html

 

An FW-190A5 “Weisse 35” was modified with a new stronger fuel pump and the fittings for this system.

Flight-testing began on 30 August 1943 and was completed on 01 September 1943. It determined that Ladedruckerhöhung

maintained oil and cylinder head temperatures within acceptable limits. Level speeds were increased on average by

36kph at 3KM in altitude and 42 kph at 5 KM altitude with an average increase of 22kph up to the 1st Gear Supercharger FTH.

Erprobungskommando 25 submitted the testing results to BMW and on 01 December 1943 the motor manufacturer returned

clearance for the system to be used for a maximum of ten minutes for further testing. It is evident that BMW was

greatly concerned about the cylinder temperatures in climbing flight. Especially in the heat of summer or the tropics,

the system would push the motor to its extremes. When the motor mounts in the FW-190A5 variant were lengthened to

restore the aircrafts CG limits it introduced a temperature imbalance between the cylinder banks of the BMW801D2.

The front bank of cylinders was now operating at a much cooler temperature than the rear cylinders. This would rob

power production of the motor and cause undue wear on the engine. In October 1943 BMW investigated the summer and

winter performance of the motor. The details of this investigation will be discussed in later articles. What is

evident is that this imbalance delayed the continuation of testing for Ladedruckerhöhung until December 1943.

The problems of cooling the motor in climbing flight combined with production of a pool of operational spare engines

further delayed Ladedruckerhöhung’s appearance in serial production until early summer 1944.

In March 1944, Focke Wulf Bremen issued a report to the RLM on the performance increases of the BMW801D2. In that

report it clearly states that Rechlin has not yet released Ladedruckerhöhung for operational use and was still

conducting testing of the system. When the operational instructions for the systems use show up in the

Flugzeug-Handbuch some major changes had been made to the cooling system by Focke Wulf and BMW.

To increase pressure around the cylinders and providing needed cooling, the baffling was tightened around the motor.

Larger internal intakes were also added to provide the increase in air volume to the supercharger as well.

In July 1944 BMW issues instructions clarifying the two boost systems in place for the BMW801D2.

These instruction notes that Ladedruckerhöhung is now standard on all production Triebwerks used by fighter variants

beginning that same month. The system is cleared for 10 minutes of use in fighter variants at all altitudes and

conditions of flight.

Ladedruckerhöhung first appears in official manuals in the September 1944, (effective July 1944), FW-190A7

bis FW-190A9 Flugzeug Handbuch Teil 07 the system is described as an airline with a series of nozzles and a

push pull valve. Power was gained by bleeding air from the supercharger pressure line.

A flexible tube drew off a portion of the boost pressure when opened and was connected to the supercharger airline

between the fuel mixture chamber and the ladedruckreglar. The two nozzles in series in the line were of different

diameters and designed to bleed off the pressure to a very low level when the actuation valve was opened.

This fooled the Ladedruckreglar of the Kommandgerät into compensating for the lower pressure by opening the butterfly

valves of the throttle wider and increasing the manifold pressure to 1.58ata in the 1st Gear Supercharger FTH

and 1.65ata in the 2nd Gear Supercharger FTH. The stronger fuel pump would then provide the required amount of fuel

increasing both power and fuel consumption. During the summer months it was noted that the system would push the

thermal limits of the motor to their maximum permissible levels. All aircraft mounting the new system will be marked

with a yellow ring 50mm in diameter with a 10mm diameter hole in the center. The ring would mount on the lower left

portion of the MG cover near the cockpit.

 

<EN POH picture>

<EN diagram>

<EN Performance>

<EN power production>

Ladedruckerhöhung improved the performance of the only serial production Anton to receive the modifications, the FW-190A8

considerably. The boost in power was much needed to overcome the 7 % weight creep in the BMW801D2 powered Antons.

Granted this is below average weight creep for a 1st line fighter design in WWII.

<AHT US fighter weight creep>

The power to weight ratio of the FW190A8 was better than FW-190A0 which so impressed the pilots of JG26 in 1941.

The increase in power left the FW190A8 competitive at low altitudes and further improved the dog fighting capability of the design.

These two systems comprise the most common power boosting systems found in the operational Geschwaders using the FW190 series.

The second part of the article will cover Alkohol-Einspritzung, GM-1 Zustatz, and field modifications.

Stayed tuned as there will more to follow shortly!

[Mac_Messer]

IL/2 was great in it's day, but it had some real warts too.

 

The real life power loading for the late 8/9 series Antons was actually pretty good - they were commented on as being the most maneuverable and best handling of the series by guys like Addi Glunz and Pips Priller.

Even I know that power loading isn`t everything for an airplane to perform better, especially if it puts on weight. You don`t just erase it with more power.

 

Surely not better than A3/A4, right?

[Sgt_Joch]

so I had a chance to look at this in more detail and if you review the available technical documentation, you can see that the Emergency System on the A8 works on the same basic principle as C3 injection in the A5, i.e. inject more fuel to progressively enrich the fuel:air mixture to minimize the risks of pre-ignition/detonation. In fact, any one who understands how engines work would see that this is the only logical explanation.

 

The first part of the puzzle as to why the engineers did not simply up the boost to 1.65 ata in the A5 in high gear is provided by the explanation in post #77 above, namely the fuel pump in the A5 just did not have the capacity to deliver the required fuel in high gear. Apart from the other technical issues explained in post #77, just upping the boost without being able to deliver enough fuel to maintain the required mixture setting would have resulted in a mixture which was much too lean with a unacceptably high risk of pre-ignition/detonation of the air:fuel mixture.

 

The next part of the puzzle is the mixture settings on the engine. It turns out the BMW 801 does have a super-rich, super-super rich and super-super-super rich settings since the  ECU automatically adjusts mixture on the fly. The system constantly adjusts the mixture and automatically moves to a progressively richer and richer setting as the RPM and boost are increased. This is explained in detail in the NACA engine bench test on the BMW 801D2. (see page 11 for a technical explanation and figures 17 and 18 for examples of how the system operates).

 

link to NACA report:

 

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930093290.pdf

 

As to how the system works in practice, this is shown in German test reports. If you look at the chart on page 6, you can see a large spike in fuel consumption. When 1.65 ata boost is engaged in high gear, predicted fuel flow jumps from 450 kg/h at 2700 rpm/1.42 ata to 550 kg/h at 2700 rpm/1.65 ata, roughly a 22% increase. Since fuel flow is largely determined by RPM since a specific amount of fuel is used on each revolution, the spike in fuel flow is to maintain a higher than normal fuel:air mixture to minimize the risk of pre-ignition/detonation.

 

link:

 

http://www.wwiiaircraftperformance.org/fw190/BMW_VB_126.pdf

 

 

Edited January 30, 2018 by Sgt_Joch

[JtD]

550kg is and has been the limit of the injection pump, and if you look at the test reports, you'll see that in low gear, where the injection of C3 was used, the increase is just from 505 to 550kg/h. This means even at 1.58ata the mixture at the higher boost is leaner than at 1.42 ata. With C3 injection the consumption was about 55kg higher, resulting in a richer mixture at 605/1.65 than both at 505/1.42 or at 550/1.58.

 

And yes, it's pretty much the same increase which you achieve in second charger gear without the injection. In second charger gear the injection pump capacity was sufficient. Since C3 injection was used only down low, it's not really relevant for the comparison of the two systems.

 

p.s.: Thank you for taking the time to go through the materials before posting and posting in the constructive manner you did.

Edited January 30, 2018 by JtD