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Gryphonne
05-22-2004, 05:55 AM
Can anyone give a detailed description of the engine CEM for the A-5 and up?

It seems you have to set the pitch back in dives else you'll overrev (esp. with erh√¬∂hte notleistung engaged). But other times when i have the pitch back it still overrevs without warning.

Also do other planes have to set back the pitch as well?


Regards,

Gryphon

Take a look to the sky just before you die, it's the last time you will!

Gryphonne
05-22-2004, 05:55 AM
Can anyone give a detailed description of the engine CEM for the A-5 and up?

It seems you have to set the pitch back in dives else you'll overrev (esp. with erh√¬∂hte notleistung engaged). But other times when i have the pitch back it still overrevs without warning.

Also do other planes have to set back the pitch as well?


Regards,

Gryphon

Take a look to the sky just before you die, it's the last time you will!

Zen--
05-22-2004, 06:41 AM
In this version of the patch it appears better to leave them on auto prop instead of manual. It used to be that 100% manual was pretty much the best setting for the Antons, but my general impression is that the whole 190/Ta series gets best performance on auto now.

Ask Hunde about the manual pitch on the A9, he flies that most of the time and he would know. I fly the D9 and the Ta152 primarily and haven't seen any need for manual prop pitch for a long time, so I stay on auto. (edit here: The D9 hasn't needed manual, in AEP 2.0 the TA152 flew like a dog on auto. Best results were on 80% manual)


The D9 still overrevs at 3600rpm, so if using manual pitch 3500 is your maximum and I wouldn't stay on that for a long time. Usually on auto pitch 3200rpm is normal at maximum power, but I wouldn't switch to manual pitch with the engine at full boost, I'd throttle down and then work the pitch from 80% and up, watching the tach to make sure 3500rpm is not exceeded. When coming into a dive you had best either switch to manual 80% or less in a hurry, or get back on auto right away because the D9/Ta will burn out the engine within seconds once 3500rpm is exceeded.

Other planes don't have this 'problem' because they get best performance at 100% manual (in most cases) and there is little reason to change pitch settings...in effect 100% manual is their auto pitch setting, if that makes sense.



-Zen-

[This message was edited by Zen-- on Sat May 22 2004 at 07:27 AM.]

[This message was edited by Zen-- on Sat May 22 2004 at 07:29 AM.]

ZG77_Lignite
05-22-2004, 10:03 AM
Just to input a little bit of information: The FW190A's use a single stage two speed supercharger, this means they 'shift' once, and this shift gives the 'bump' in the horsepower (speed) curve. The P51 uses a two stage two speed supercharger, which means it has a more 'flexible' horsepower (speed) curve, it SHOULD have more available horsepower at various altitudes than the FW190As.

As a side note, the FW190a shifts around 3000m (above or below depending on atmospheric conditions). Hunde, did you achieve enough altitude for the supercharger to shift into high gear? If not, you will be operating at significantly(!) lower horsepower, where as the P51 has a wider horsepower band due to its 2stage2speed supercharger.

Willey
05-22-2004, 10:32 AM
There are some big errors in 190A Engine management.

1. The prop. It was a VDM Verstellschraube, with an rpm to manifold pressure automation in the Kommandoger√¬§t. If this link was disabled (the only manual control except the cooler setting), the prop revs weren't limited anymore, just like in the 109s. Basically it has a CSP + Auto in FB, but it should have a fully variable + Auto like the 109 has. On the trottle lever, there's a small rocker to adjust the airscrew angle in manual mode. If Auto was disabled, the angle kept at the last position (in FB it would jump to 100% http://ubbxforums.ubi.com/infopop/emoticons/icon_biggrin.gif).
As for the D series and 152s, FB is also wrong. These used real CSPs http://ubbxforums.ubi.com/images/smiley/16x16_smiley-happy.gif (that's also why they have no prop pitch indicator anymore http://ubbxforums.ubi.com/images/smiley/16x16_smiley-wink.gif). The D-9's prop was a "Junkers VS-111 Propeller mit konstanter Geschwindigkeit", IIRC (there's an US translation of a Dora manual which I have on my HDD).

2. In A-5 and A-6, the WEP system is not modelled correctly. Performace-wise it is not modelled at all (=1,42ata, 2700rpm; 1780hp performace). It was called "Ausreißhilfe" and was developed for the JaBo 190s (F/G), and installed later in A-5s. AFAIK the A-6 had it already by default, but I may be wrong. This WEP worked similarly to the La-5/7 Forsazh, using high boost gear and very rich mixture setting to increase power to ~2000hp with 1,58ata @ 2800rpm. Because of the 2nd supercharger gear used for this extra boost, it couldn't be used above 1000m. (I'm not 100% sure about this system, but this would be the only valid explanation for the low alt limitation, just like in the Las). BTW this one couldn't be used very long, and normally the engines had to be changed after a use of this WEP http://ubbxforums.ubi.com/images/smiley/16x16_smiley-happy.gif.
The A-8 then introduced another high pressure fuel injection system which allowed boost at all altitudes with 1,65ata @2800rpm, giving 2050hp max. This one was also installed on Doras quickly after it was found out that it's performance was insufficient.

3. Not a real error, but the A-4 is limited to 1560hp, 1,32ata @ 2400rpm in FB. They could be unlocked and had 1780hp, 1,42ata @2700rpm then, just like the A-5 - but it could only be used for a single minute. Especially JaBos removed the derating to be able to get out of the target area quickly after they attacked. The A-5 and laters could use this power for longer time because they had a better cooling system.

ZG77_Lignite
05-22-2004, 11:44 AM
Holy @#$% my above response was intended to go in Hunde's post about speeds at altitude (thus compared with P51). I suppose the post I put in there belonged in here, doh! Well, I'm off to see if I can reverse this screwup, apologies.

P.S. Next post will hopefully go in the right place, as I disagree with what Willey is saying.

ZG77_Lignite
05-22-2004, 11:51 AM
Willey, regarding your point #1:

I believe that to be incorrect, in that the VDM prop for the FW190A's Was a constant speed unit, in addition to the RPM/manifold pressure automation in the Kommandergerat.

According to the NACA report (as I interpret it), the prop was a constant speed unit, in turn the constant speed unit was controlled by the Kommandergerat (which maintained correct manifoldpressure/RPM relationships). IF (and only if) the constant speed unit failed (from damage or mechanical failure) then there was a Direct electric Backup (this is technically the 3rd stage of backup for the prop system) was available to the pilot.

In this back-up regime (after failure of CSU) the prop acts similar to the Bf109 setup. But the CSU unit still operates (unless destroyed) even if the Kommandergerat fails (due to high altitude hydraulic pump failure for example), however the CSU no longer maintains correct manifold pressures-->RPM-->mixture-->supercharger-->sparkadvance under such circumstances, but the prop still maintains engine RPM (constant speed operation). Thats how I interpret the report, at least.

ZG77_Lignite
05-22-2004, 12:00 PM
Also, Willey, regarding point #2, I'm less familiar with, but I think the A5 and A6 (as well as the A8) are using a different system than you describe. The system you describe Is modeled in FB FW190F8 I think, correctly or not I don't know, but similar to the La5 Forzazh.

But for A5/A6/A8 I believe we have the direct C3 fuel injection, which unless I'm mistaken is different from what you describe. The C3 fuel injection is the direct result of the lack of the MW50 injection mechanism (BMW801 was prepared for this from A4 and up, but never used), and does not directly relate to supercharger gears, the C3 fuel is injected directly into the supercharger at either supercharger speed, to decrease detonation/increase cooling and allow for higher manifold pressures.

Again, I'm not an expert, just parroting back stuff I've picked up from Butch, as well as a couple of other FW190 experts. I'd be happy to learn more, if I have it incorrect.

Hunde_3.JG51
05-22-2004, 12:20 PM
I use 80% prop-pitch in all 190A's. Top speed is higher than in auto and only about 2km/h less than on 100% and it keeps the rpm's down.

http://www.militaryartshop.com/prints/bailey/warwolf.jpg

Formerly Kyrule2
http://www.jg51.com/

Gryphonne
05-22-2004, 02:24 PM
Hunde,

What about acceleration, zoom and climb then?

I'd say 100% works miracles there.

Take a look to the sky just before you die, it's the last time you will!

Hunde_3.JG51
05-23-2004, 03:23 AM
I don't notice much difference between 80% and 100% in acceleration or zoom. Sometimes in climb I will bump it up to 100% but I usually leave it at 80%. At 100% prop-pitch overheat comes on very quickly.

http://www.militaryartshop.com/prints/bailey/warwolf.jpg

Formerly Kyrule2
http://www.jg51.com/