Questions regarding the FM of the Fw-190 A-8/9

[JtD]

The A-9 used the BMW 801TS engine. It achieves the power output of the TH, but as it used the old prop reduction gear of the TU engine, erhöhte Notleistung was not permitted. It was permitted with the later TH engine, which was about to enter production when the war ended.

[War_Emergency_Picnic]

Stumbled
upon this at ww2aircraft by the user FLYBOYJ...

"The engine was controlled by an ingenious, advanced Kommandogerat-a
sort of electronic brain box that greatly relieved the pilot's
responsibility to control airscrew pitch (rpm), fuel mixture and engine
boost (throttle) in combat. In addition, the engine's two-speed
supercharger shifted automatically at about 21,000 feet, and •••control
of the important oil-cooler flaps was automatic•••, thus relieving the
pilot of two more major cockpit duties. The pilot needed only to keep
his hand on the throttle and his eye on his assailant. In the heat of
combat, it was very easy for an Allied fighter pilot to forget to move
one or both of the other two required controls if he needed immediate
full power to beat his opponent."

He never stated the variant though...

I'm starting to get confused now, and more so because now I want to do
an all-nighter about the Kommandogerat.

[Treetop64]

Originally Posted by War_Emergency_Picnic

Stumbled
upon this at ww2aircraft by the user FLYBOYJ...

"The engine was controlled by an ingenious, advanced Kommandogerat-a
sort of electronic brain box that greatly relieved the pilot's
responsibility to control airscrew pitch (rpm), fuel mixture and engine
boost (throttle) in combat. In addition, the engine's two-speed
supercharger shifted automatically at about 21,000 feet, and •••control
of the important oil-cooler flaps was automatic•••, thus relieving the
pilot of two more major cockpit duties. The pilot needed only to keep
his hand on the throttle and his eye on his assailant. In the heat of
combat, it was very easy for an Allied fighter pilot to forget to move
one or both of the other two required controls if he needed immediate
full power to beat his opponent."

He never stated the variant though...

I'm starting to get confused now, and more so because now I want to do
an all-nighter about the Kommandogerat.

Could be talking about the Bf109F or G as it also had the Kommandogerat, as well as thermostat controlled radiator and oil cooler flaps. Again, owing to unique design of the FW's oil cooling system, it did not have oil cooling flaps.

[Crumpp]

The FW-190A9 with the BMW801TS engine was cleared for a straight manifold pressure increase to 1.78ata @ 2700U/min in the 1st gear supercharger in January 1945 and 1.82ata @ 2700U/min in the second gear supercharger.

The War Technical Diary of the Luftwaffe K.T.B 15/1-21/1 January 1945 clarifies the manifold pressure increase is approved for all engines and does not require Alkohol-Einspritzung or C3-Einspritzung.

The instructions clarify earlier instructions for emergency power increases to the BMW801 series that caused confusion at an Engineering meeting at Bad Eilsen between Focke Wulf, GmbH and BMW.

[Faustnik]

Originally Posted by Crumpp

The FW-190A9 with the BMW801TS engine was cleared for a straight manifold pressure increase to 1.78ata @ 2700U/min in the 1st gear supercharger in January 1945 and 1.82ata @ 2700U/min in the second gear supercharger.

The War Technical Diary of the Luftwaffe K.T.B 15/1-21/1 January 1945 clarifies the manifold pressure increase is approved for all engines and does not require Alkohol-Einspritzung or C3-Einspritzung.

The instructions clarify earlier instructions for emergency power increases to the BMW801 series that caused confusion at an Engineering meeting at Bad Eilsen between Focke Wulf, GmbH and BMW.

Here is a chart with this ata.

[Crumpp]

It would be like saying someone can't put a turbo on their car because they have a 2.73 ratio rear end.

Right.

I don't see the relevance and wonder what the point being made about the reduction gear happens to be.

Manifold pressure increased but rpm remained the same.

Increasing manifold pressure is the most efficient way of increasing an airplane engines power output.

In the power formula, rpm is divided by 2 so you have to double the rpm for each increase in output.

Of course, you can't realize a very large gain in power without reducing the propeller diameter due to mach losses.

A small increase in manifold pressure of .13 ata realized a 200PS gain in static BHP raising the engine output from 2000 static PS to 2200 static PS at sea level. The power rises slightly (50PS) on the static PS graphs to FTH.

That is static power.

The performance benefits are obvious as noted in the graph Faustnik posted.

One the cooling fins, the BMW 801 series was an air-cooled engine. It does not require oil cooler adjustment as such. Basically air cooled engines operate over a huge range of temperatures when compared to a liquid cooled engine. They are designed that way!!

Liquid cooled engines are much more temperature sensitive and operate over a very narrow range. Water has 25 times the heat absorption capability of air so the engines temperatures remain pretty stable as long as the coolant temperature is within limits. Thus, generally speaking, Liquid cooled engines tend to have longer TBO's than air-cooled engines.

In fact, air cooled engines with oil coolers can suffer from overcooling in the wintertime.

Overcooling is a condition where the oil is not heated up enough to evaporate water and other contaminants from the oil. Overcooling causes internal corrosion which leads to cam spalling and bearing failure.

Lots of air-cooled engines have cowl flaps. The cooling gills on the BMW are just that, cowling flaps. They have nothing in common with radiator inlet controls.

If you read the Flight Manual for the FW-190, except for some specific conditions of flight such as climb in high density altitude conditions, you just leave them closed once the engine is warmed up.

It is not something a pilot would be adjusting constantly like the radiator inlet on a liquid cooled engine.

In general, since water/glycol has a much higher heat capacity than Air, you need a lot of air flow to reduce the temperature a little in a liquid cooled engine.

Read the Operating Notes / Flight Manuals, they will tell you everything.

[Crumpp]

If you read the Flight Manual instructions for Erhöhte Notleistung as found in the FW-190A8 dated July 1944, you will see statement about the BMW801TU not being cleared for it is wrong.

[Bolelas]

Originally Posted by Crumpp

Lots of air-cooled engines have cowl flaps. The cooling gills on the BMW are just that, cowling flaps. They have nothing in common with radiator inlet controls.

I liked your explanation about diferences in air cooled/water cooled engine differences. (always learning, thank you.)

But, clarify this for me: those inlet controls, or cooling gills that you mention, they work by controling the amount of air that passes through someting, correct? Either cooling the water, or passing by the engine surface, wright?
And if they have more diferences, please clarify.

(Just asking because i dont have sure, not trying to prove anything or argue)

Originally Posted by JtD

The A-9 used the BMW 801TS engine. It achieves the power output of the TH, but as it used the old prop reduction gear of the TU engine, erhöhte Notleistung was not permitted. It was permitted with the later TH engine, which was about to enter production when the war ended.

The only thing the gear ratio would do is define the propeller. It would be like saying someone can't put a turbo on their car because they have a 2.73 ratio rear end. (Admittedly a poor analogy - car analogies always are - lol.)

[JtD]

Originally Posted by zipper

The only thing the gear ratio would do is define the propeller. It would be like saying someone can't put a turbo on their car because they have a 2.73 ratio rear end. (Admittedly a poor analogy - car analogies always are - lol.)

Gears just like any other part have their mechanical limits. So the reason to not put a turbo into your car would be because the gear can only transmit 350Nm of torque.

Anyway, true that the TS was cleared for 1.82 ata later on, in fact the engine's been modelled with, but it was included without because the A-9 in game is a designated a 1944 aircraft.