[Karaya]

How do you really know that Russian made test with 1.3 Ata ? We have unkown condtion about Russian test or maby you have it?

In most russian data i found there is 1475 KM for 109 G-2:





See Finish G-2 test which were surly for 1.3 Ata:

http://kurfurst.org/Performance_tests/1 ... 15_en.html


And here we have for 1.3 Ata Bf 109 G-1 Rechlin:




Alse here are test for 109 G-2 Trop 1.3 Ata and 1.42 Ata

http://kurfurst.org/Tactical_trials/109 ... mPerf.html

I know that FM data not corenspond with in game performance ( see overspeed in game Tempest 11&13lbs performance, Fw 190 D-11 and D-13 ) but still i think that F and G moddels are much more realistic handling that G-2 model which is a lot of underweight. German pilots opinion and also test show that 109 G moddels had worse handling and turn performance then F series.

First off, I respect your opinion, just want to show you some of the conflicting data shown in various test reports

A lot of tests on all sides have to be taken with a grain of salt (or two)

For example, there's a British test report on a 109G-6 that shows horrible speed, climb and turn performances but fails to mention at the same time 2 very important facts:

The fact that the aircraft was rather worn out and the fact that it was carrying gondola armament which impairs almost all performance characteristics: speed, climb, turn,... no wonder the G-6 did less than spectacular!

I will see if I can dig it up, cant search for it right now as I'm not at home.

In the Finnish test report you have posted here, notice this:

During the tests, 1.3-1.32 ata and 2540 RPM was realized, though such small variations were within tolerance, the lower RPM and/or other factors appear to have somewhat impaired the supercharger`s performance, and thus may have reduced altitude performance, as seen from the performance curves : the rammed rated altitude of 6,3 km was considerably below not only the nominal value (of 7 km) of the DB 605 A, but also the typically obtained, avarage 6,6-6,7 km rated altitude. For this reason is it interesting to extrapolate the level speed curves of MT-215 to 7 km rated altitudes, which shows an extrapolated speed of ca. 650 km/h. The extrapolated values show matching result with those obtained on Bf 109G-4 WNr. 19 968, that was tested by the NII VVS in a very similiar configuration (ie. tailwheel was non-retractable in that case as well) in October 1943. This points to that the poor high altitude performance shown by MT-215 was likely to have been caused by a defective supercharger and/or lower supercharger speeds due to lower engine RPM..

as well as:

As a late production Bf 109G-2, WNr. 14 783 / MT-215 was fitted with an enlarged, non-retractable tailwheel as opposed to the previously retrractable one; this change caused -12km/h loss of speed at SL. This needs to be kept in mind when comparing the results with previous trials of the Bf 109G featuring retractable tailwheels.

Theres an error there actually as the -12km/h loss is meant for high altitudes really! At low altitudes the speed loss resulting from the fixed tail wheel is rather minimally and only in the order of ~5km/h!

So from the above extrapolated 650km/h at 7000m for a "good condition" G-4 + 12km/h for a retractable tailwheel we end up roughly at the same topspeed as depicted in IL-2 --> 662 vs 666km/h!

On topic of the Russian chart you posted:

Notice how the Bf109F-4 is quoted with a DB601E of 1350PS but at the same time with a topspeed of just 624km/h?

The Bf109F-4 reaches a topspeed of 630km/h after Rechlin tests with a DB601E at 1.3ata (1250PS at takeoff) and ~650km/h with the same engine at 1.42ata (1350PS at takeoff).

It is similar for the G-2, 1475PS (1.42ata) but 650km/h (very roughly speaking) 1.3ata performance at the same time on the chart. Seems like the Russians were just copying German manuals without cross-checking!

The other British test also has its flaws:

First of all it is a Tropical version so outfitted with a sandfilter that results in about 10-15km/h of speed loss at altitude. Furthermore it is again noted:

While these figures are in reasonably good agreement with the data obtained from other sources, the aircraft was not in perfect condition; for instance the oil radiator flap was locked open as mentionedin the extracts given above. Moreover, the figures in tables 4 ad 5 apply to the Tropical version fitted with an air-cleaner.

The other performance figures are only calculated and not out of an actual test and therefore to be regarded as speculative, especially as the British would give the G-2 only a topspeed of 395mph in clean configuration, that is 635km/h, the lowest figure I have ever seen for it! Even the G-6 is quoted as being faster than that in most tests!

And last but not least I again repeat:

It might very well be that the 109Friedrich simply is undermodelled in its handling which most test data points towards. The G-2 with a little thought seems to be very well represented both in speed, climb and turning peformance. The G-6, being only 70kg heavier in real life (thats only ~2.5% more) and slightly less aerodynamic (locked tailwheel, MG bulges) should only really differ in topspeed both at SL and at altitude, the 70kg hardly have an effect at the aircrafts handling at all!

[Karaya]

Sry i cant agree. In game 109 G-2 (1540 HP so 1.42 Ata) is faster, have better climb rate, better powerloading and with lowered weight has also lower wingloading so with these all superiror things its definitly handles better then F-4.

G-2 with 1.3 ata IRL shoud be between in handling between F-4 and G-6.

The DB605A used by the 109G-1 to G-8 had a maximum rated power output of 1475PS at 1.42ata, 1310PS at 1.3ata. The 1540PS (actually 1550) you put up are actually for the higher altitude rated DB605D which was a very rare sight on early mark Gustavs and only a stop gap in the development leading up to the later MW50 powered high altitude marks such as the DB, DC, DM, ASB, ASC, ASM,...

AGAIN, my very own take about the whole 109F/G2/G6 affair is that both the Fs and G6s are impaired in their handling whereas the G-2 seems very closely modelled to accurate data that can be found on it!

[Test Pilot]

Sry i cant agree. In game 109 G-2 (1540 HP so 1.42 Ata) is faster, have better climb rate, better powerloading and with lowered weight has also lower wingloading so with these all superiror things its definitly handles better then F-4.

G-2 with 1.3 ata IRL shoud be between in handling between F-4 and G-6.

The DB605A used by the 109G-1 to G-8 had a maximum rated power output of 1475PS at 1.42ata, 1310PS at 1.3ata. The 1540PS (actually 1550) you put up are actually for the higher altitude rated DB605D which was a very rare sight on early mark Gustavs and only stop gap in the development leading up to the later MW-50 power high altitude marks such as the DB, DC, DM, ASB, ASC, ASM,...

AGAIN, my very own take about the whole 109F/G2/G6 affair is that both the Fs and G6s are impaired in their handling whereas the G-2 seems very closely modelled to accurate that can be found on it!

Yes you right devil alway be in detail.

Still there we have many varoius of 109G test and reports. I know that these is really problem for choice the most realiable. So the most reliable are always orignal scans which hasnt got any traslation errors. I really know that its really pain to create FM for planes.

Ad. to 1540 HP it is enigne power actually set for DB605 engines ( which use G-2, G-6) in our game so it is also overated.

I think some test 109 G was made both with 1.3 Ata and 1.42 Ata thats way there are different results ( not only retractable tail wheel) . See British test G-2 Trop also russian probalby could make test with 1.42. German restricted for 1.3 Ata because engine failures. See also German G-1 Rechlin.


Unfortunately there are many bugs and wrong data in game and taking also engine which make it in own way also its really hard to keep things in the accurate way.

For my opinion G-2 is little too good handling plane comparing to expecially F moddel but as you mention also some spits are too good - some less.

I rather see F-4 corrected with speed and engine powers ( maby we need 2 version also) and G-2 corected with weigth and handling with actual speed peformance.

I think to make fair and accurate Fm's we must to get plane one by one and make it from the beginign which surly take years

[Guest]

The DB605A used by the 109G-1 to G-8 had a maximum rated power output of 1475PS at 1.42ata, 1310PS at 1.3ata. The 1540PS (actually 1550) you put up are actually for the higher altitude rated DB605D which was a very rare sight on early mark Gustavs and only a stop gap in the development leading up to the later MW50 powered high altitude marks such as the DB, DC, DM, ASB, ASC, ASM,...

DB 605A

1475PS at 1.42ata - 0 km
1550PS at 1.42ata - 2.1 km

[Test Pilot]

In game 109 G-2, 109 G-6 and G-6 late have engine Db605 with 1540 HP data and 1.42 Ata modeled.

Should be rather in these way:

G-2 1.3 Ata - 1310 HP

G-6 early - the same

G-6 late - 1.42 Ata - 1540 HP

[Guest]

and pretty much anything you guys can propose that needs only minimal 3D work (FM is no problem, I can make all that!)

Bf 109E-1 new FM
Bf 109E-3 new FM
Bf 109E-4 new slot and new FM
Bf 109E-4/B new slot and new FM
Bf 109E-7 new slot and new FM
Bf 109E-7/B new slot and new FM
Bf 109F-1 new slot and new FM
Bf 109F-2 new slot and new FM
Bf 109F-2/B new FM
Bf 109F-4 new slot and new FM
Bf 109F-4/B new FM
Bf 109F-4/R1 new slot and new FM
Bf 109F-4 1.42ata., 1942. new slot and new FM
Bf 109G-2Early new FM
Bf 109G-2Late new FM
Bf 109G-4 new slot and new FM
Bf 109G-6Early new slot and new FM
Bf 109G-6Late new slot and new FM
Bf 109G-6EarlyC3 new slot and new FM
Bf 109G-6LateC3 new slot and new FM
Bf 109G-14 new slot and new FM
Bf 109G-14C3 new slot and new FM
Bf 109G-10 new slot and new FM
Bf 109K-4 new slot and new FM
Bf 109K-4C3 new slot and new FM

[Karaya]

Bf 109E-1 new FM

That one will get an own FM when its out of Beta as far as I know!

Bf 109E-4 new slot and new FM
Bf 109E-4/B new slot and new FM
Bf 109E-7 new slot and new FM
Bf 109E-7/B new slot and new FM

Dont see much wrong with those, especially as we now have the /N versions out that complement them performance wise very nicely!

Bf 109F-1 new slot and new FM

Has the same FM as the F-2 which is correct as the only difference is in the armament (MGFF/M instead of MG151/15)

Bf 109F-2 new slot and new FM
Bf 109F-2/B new FM
Bf 109F-4 new slot and new FM
Bf 109F-4/B new FM
Bf 109F-4/R1 new slot and new FM

Again dont see what needs a new FM here

Bf 109G-2Early new FM
Bf 109G-2Late new FM

They are also good as is, no?

Bf 109G-4 new slot and new FM

Wait and see...

Bf 109G-6Early new slot and new FM
Bf 109G-6Late new slot and new FM

We already have that! hock: :?

Bf 109G-6EarlyC3 new slot and new FM
Bf 109G-6LateC3 new slot and new FM

Erhm, what? C3 is the fuel being used on the plane, namely 97octane. I cant think of any DB605 engine that ran on C3 fuel that was actually used on the G-6 in numbers! Such engines would be the DB605 ASC & DC, none of those were used on the G-6 and were reserved for later models such as the G-10/-14/K-4

Bf 109G-14C3 new slot and new FM

We already have the G-14/AS with a DB605ASB engine, 1800PS at takeoff, 690km/h @ 7500m

Bf 109G-10 new slot and new FM
Bf 109K-4 new slot and new FM
Bf 109K-4C3 new slot and new FM

Also good as is IMHO


Is was looking for more diversified suggestions, not only restricted to the Bf109!

I'm also currently working on a Mustang Mk.IV 25lbs version similar to the existing Mk.III Mustang.

[vanir]

I've written a lot on these boards recently which hopefully display a consistently continuing, dedicated research on the Daimler motors in particular (I've been diversifying into the Jumos lately). In the past I've brought up many of these points, been corrected here and elsewhere and continued dedicated research of documentation and the opinions of qualified authors to be found at such places as Luftwaffe experten or their own websites.
What I've been mostly investigating lately has been the various flying conditions of aero engines, in particular the Daimler and Jumo. That is, climbing condition, cruise condition and high speed condition, also varied fuel types, additives and boost systems.
It is really because I find arguments when we all have a common interest upsetting when I'm on the receiving end of them, and so I've gone away, done more research and come back with a little more understanding each time.

I have found for example certain widely recognised experts fell along the way regarding detailed aircraft mechanics, say for example at one time I had strong arguments describing documentation for boost systems, poorly understood, and no explanation of how the system actually worked mechanically forthcoming. That took quite a bit of learning, I've since cleared up certain inconsistencies with popular ~interpretations~ of said documentation and have come off better for it, with a new circle of even more qualified persons who now speak with me regularly. I feel quite honoured in this.

Back to topic, I've flight tested each of the new models/FMs released by Muas and Karaya here and I can't thank them enough. According to all my combined research they've done a fantastic job, the whole 109 series is really looking good now and feels great to fly.

Now it's not perfect, the Il2 engine is limited we all surely understand this. But the spread we've got at the moment, particularly with the addition of the E/N series and corrected G-6 FM in two versions, the ASB engine for the G-14/AS and a DC engine for the G-10 nicely modelled, plus the stock 109s we have now represented the wide variety of build quality and model performance available in the 109 particularly from 1944, with some corrections for 1943 and additions for 1939-41.

I've always liked the F-2 and F-4 modelling myself, outright speed capabilities pale in comparison to sustained combat performance and mate, you cannot beat an F-4 in late 41. Push the throttle to full military, sit back and enjoy the ride, that thing downs anything. I love doing Medi missions against Vc Spits, it kills 'em because of that amazing sustained performance.

And this is also the trick about historical aircraft. The vast majority of their performance potential is in the cruise and climbing condition. This is your average engagement speed and sustained combat performance. Full military is just a little boost when you need it. Top speed is what you use to escape combat. Well the F-4 can sit around doing full military for the whole fight. No other stock 109 does that, most of the stockies cruise too hot to start with.

Most particularly the corrected FMs by karaya seem to have far more reliable performance under normal flying conditions and this far and away makes these aircraft more effective in combat. It is also the major point I felt with all the stock Luftwaffe models that seemed to challenge German documentation and postwar testing (wartime testing was often either patriotic in nature or ignorant of proper maintenance schedules) and screamed Allied favouritism in il2. This has been brought up by so many enthusiasts the term "Luftwhiner" was coined. Oleg states in il2 that the build quality in late war German was a major consideration.

So now we have both examples here, some good individual models and some stock ones which aren't too disadvantaging so long as they're not the only ones available. And I've always wanted to see the 601N motor in Emils.

Thus far to me, Muas and Karaya have been a dream come true.

My only suggestions for new slots are these:

K-4/ASC engine with improved cruising condition over the DC. This motor has the rated altitude and cruise performance of the ASB combined with the FTH and full military performance of the DC, and is easily the most refined and highest performing 109 to be equipped in numbers.

Ta-152C-1 with C-3 Mk103 motorkanone option. I've corresponded with Dietmar Hermann about this aircraft (a published authority on the type) and he sent me some specific figures which seem to differ in some respects to the stock modelling.
There are two flying conditions apparently tested, B4 or C3 fuel and it appears the stock modelling is for the B4 version. This is likely to have been switched for C3 in initial production batch due to the lack of intercooler which was to be fitted to the 603L motor replacing the 603LA in early production.
MW50 was being used as a substitute for intercooler in the test prototypes and early planned production, whereas later with the exchange of the 603L motor it was to have been tuned for performance enhancement. The difference is likely to be similar performance to the C3 fuel LA motor mit MW50.
The B4/MW50 LA is 1780/2050PS takeoff. The C3/MW50 LA is 2100/2300PS takeoff. The B4/MW50 L motor is likely to be 2000/2300PS takeoff.

This is a vital aircraft type for any Luft-46 campaigning since it is the primary piston fighter entering production during 1945. It was to replace all Fw-190A and D in production, as well as take on the zerst

[ROSOBORONEXPORTCORP]

As you are so keen to make new planes

One recommendation:
- Many Ar-234s had their rearward firing MG151 removed to save weight.
- In addition, they often flew with a single 500kg bomb on the centreline and no bombs under the nacelles/engines (for some reason these reduced payloads aren't available in the default aircraft - although they should be).

So, an Ar-234 field mod might with reduced armament might be a very quick mod to make (I'd do it myself except I could never get the ******* to recompile properly).

[brentce]

My only suggestions for new slots are these:

K-4/ASC engine with improved cruising condition over the DC. This motor has the rated altitude and cruise performance of the ASB combined with the FTH and full military performance of the DC, and is easily the most refined and highest performing 109 to be equipped in numbers.

Hello Vanir

I have to ask- have you seen any documentation that the DB505AS ever ran at 1.98 ata operationally, or that any version of the DB605AS was ever installed in the K-4? Both seem extremely unlikely. It's still a very valid question whether or not the DB605DC was ever operationally cleared for 1.98 ata, let alone a DB605AS variant.

Having said that, the new Bf 109G-14/AS is a really, really nice piece of work and a great *historical* addition!

Brent

[vanir]

Hi brentce
I did some research on this a while back but my most immediate reference simply cites Mercedes Benz AG archives in Germany (this particular page is simply in a handy spot on my computer for quick reference), though since you bring it up I might look some other primary source documentation up, I'm sure I've seen some extrapolating 1.98ata.
I've been more involved with Fw-190/Ta-152 research lately.
According to archives the 605DB and DC were definitely fitted to the K-4 in service. War records going much into 1945 are extremely sporadic, the archives suggest some ASC fitments are likely during 1945, whilst similarly they are also "likely" for the G-14/AS (both ASB and ASC motors). The difficulty is that these motors were not available until 1945, when record keeping sort of got tossed out the window. Certainly some pilot reports claim that whilst some G-14 had shocking build quality and performance, some individual examples had performance equivalent to the G-10 or K-4 during 1945.
I'll get back to you.

I will add however to recall what the AS motor describes. The basic engine was a 605A fitted with the 603 supercharger for increased rated altitude and full throttle height. Both these engines experienced great difficulty when run at sondernotleistung due to problems with the pistons (they burned and holed). Plus service life and general serviceability was dramatically reduced under these conditions.
The ASB and ASC motors of 1945 appear to be the same 603 supercharger adaptation to the DB and DC basic engine. The DC is I'm certain rated for 1.98ata for the full 5min start und notleistung and sondernotleistung using C3 fuel and this was used in service. Hence I see no reason for the ASC to be any different.
The ASB and ASC are not 605A base motors, they're 605D series.

edit.
I've got some archival documentation on production motors for Daimler Benz. Both the ASB and ASC are listed as in production during 1945 and engine details are listed. The ASB could use either C3 or B4 fuel, with B4 fuel MW50 was used with sondernotleistung at 1.8ata. The ASC used C3/MW50 at 1.98ata in the production motors. No restriction for this setting is given. These details are the same of course for the DB/DC engines listed in production during 1944.
The ASM motor documentation appears to suggest some engine damage issues with the C3/MW50 adaptation of the 605AS and that sondernotleistung should not be engaged under 1.4km. I've read about the piston damage issues elsewhere, but the 2min restriction for MW50 use at sondernotleistung for the ASM (and AM) motor I've actually taken from Oleg's reference to researched data, though I'm sure I could also find these documents as readily available, just a matter of tracking them down.
These restrictions do not apply to the D series 605 however, which had no issues firstly with using B4 fuel with MW50 for improved outputs over 605A series using C3/MW50, and up to 1.98ata using the latter fuel combination. It is a common notation the 605D was further developed for 1.98ata specifically (but I fully understand your reservations about actual service fitment of this version).

Nevertheless the question would then remain, where did all the 605DC and ASC engines which were definitely produced in 1944-45 go? Surely they did not simply lay around factory floors when even 605A-1 were being tossed into G-14 airframes as necessity dictated.
And there is no listed restriction on 1.98ata I can find for the DC/ASC.

My question to you would be, what are your sources there was any issue with 1.98ata for D series motors?

edit #2.
forgive me, I'm a little tired and drinking. The confusion appears to be in the belief that the ASB and ASC are "AS series" motors, which is not exactly true. The AS is an A series. The ASB/ASC are D series.
This should answer your question.

[brentce]

Hi brentce
I did some research on this a while back but my most immediate reference simply cites Mercedes Benz AG archives in Germany (this particular page is simply in a handy spot on my computer for quick reference), though since you bring it up I might look some other primary source documentation up, I'm sure I've seen some extrapolating 1.98ata.
I've been more involved with Fw-190/Ta-152 research lately.
According to archives the 605DB and DC were definitely fitted to the K-4 in service. War records going much into 1945 are extremely sporadic, the archives suggest some ASC fitments are likely during 1945, whilst similarly they are also "likely" for the G-14/AS (both ASB and ASC motors). The difficulty is that these motors were not available until 1945, when record keeping sort of got tossed out the window. Certainly some pilot reports claim that whilst some G-14 had shocking build quality and performance, some individual examples had performance equivalent to the G-10 or K-4 during 1945.
I'll get back to you.

I will add however to recall what the AS motor describes. The basic engine was a 605A fitted with the 603 supercharger for increased rated altitude and full throttle height. Both these engines experienced great difficulty when run at sondernotleistung due to problems with the pistons (they burned and holed). Plus service life and general serviceability was dramatically reduced under these conditions.
The ASB and ASC motors of 1945 appear to be the same 603 supercharger adaptation to the DB and DC basic engine. The DC is I'm certain rated for 1.98ata for the full 5min start und notleistung and sondernotleistung using C3 fuel and this was used in service. Hence I see no reason for the ASC to be any different.
The ASB and ASC are not 605A base motors, they're 605D series.

Hey Vanir

Thanks for the quick response! I believe your mistaken that DB605ASC is a DB605D-based motor. I'm almost certain that it's a DB605A with the same larger DB603 supercharger as the DB605AS, ASM and ASB, but configured for C3 fuel. These being analogues to the DB605DM, DB and DC. It's my understanding that the 605AS's were of similar power ratings as the 605D but less robust.

While the 605DC was intended to be cleared for 1.98 ata we still haven't seen clear evidence that it was, just that it continued to be tested into 1945. I haven't seen any evidence that the 605ASC was cleared for operations at 1.98. In fact it doesn't appear that there was any service testing of this configuration. I'm sure there's plenty of documentation in the MB/DB archives for various potential 605A and D configurations, but operational clearance and use by the concerned air force is where the rubber meets the road in the historical sense.

Brent

[vanir]

Actually the 605D/C2-C3 fuel was first fitted to preproduction prototypes for the 109K, was adapted for MW50 (DM motor) then evolved firstly into the D-2 using either B4 or C3 and finally into the DB and DC variants which entered production (MW50 standardised for both). No "DM motor" entered production, but the D and D-2 entered production for development purposes.

Here is the specifics for analoguous comparison between AS/A motor, and ASB/DB or ASC/DC motor.

Climing condition (standard 30min setting, no MW50 use)
AS 1275PS with 1150PS @ 7.8km
ASM 1250PS with 1150PS @ 7.8km
AM 1275PS with 1250PS @ 5.8km

ASB 1430PS with 1285PS @ 6.9km
DB 1430PS with 1285PS @ 6.8km

ASC 1400PS with 1285PS @ 6.8km
DC 1370PS with 1285PS @ 6.8km

Full Throttle Height performance/MW50 use
ASM 1500PS @ 6.4km
AM 1700PS @ 4km

ASB 1600PS @ 6km
DB 1600PS @ 6km

ASC 1800PS @ 6km
DC 1800PS @ 6km

Rated altitude
AS/ASM 7.8km

A/AM 5.8km

DB/DC 6.8km

ASB/ASC 6.8-6.9km


So the figures clearly stipulate the AS motor is a supercharger alteration to the A motor. Whilst the ASB/ASC motor is a supercharger alteration to the DB/DC motor.
Documentation says the AS was developed by mounting the 603 supercharger to the 605A. One can reliably infer the ASB/ASC was this same method applied to the 605D which was done in 1945, using the figures provided for engine performance between the 605 series in full.

It also makes a great deal of sense, considering the reliability and serviceability issues when applying MW50 boost to the A motor, which were not a problem with the D motor.

But again I must ask, what are your sources for holding such reservations about D motors using 1.98ata?
And a new question, what leads you to think the ASB/ASC are constructed from an A motor base like the AS, rather than the D motor base in current production in 1945? It would seem a rather backwards step would it not?

edit.
I should add for prosperity the stipulation of 603 supercharger fitment lay in the cruising conditon of the ASB/ASC compared to the DB/DC, which is a kilometre higher for the same output.
The D series obviously had a larger supercharger casing than the A series to begin with, which blurs the line between it and the AS, combined with increased flow dynamics through the cylinder heads which can alter performance outputs at altitude as well, hence an easier handling of higher pressures in the standard settings.
The lines between DB/DC and ASB/ASC are really very blurred until you examine cruising condition, where the larger supercharger fitment is clear.

[brentce]

Actually the 605D/C2-C3 fuel was first fitted to preproduction prototypes for the 109K, was adapted for MW50 (DM motor) then evolved firstly into the D-2 using either B4 or C3 and finally into the DB and DC variants which entered production (MW50 standardised for both). No "DM motor" entered production, but the D and D-2 entered production for development purposes.

Here is the specifics for analoguous comparison between AS/A motor, and ASB/DB or ASC/DC motor.

Climing condition (standard 30min setting, no MW50 use)
AS 1275PS with 1150PS @ 7.8km
ASM 1250PS with 1150PS @ 7.8km
AM 1275PS with 1250PS @ 5.8km

ASB 1430PS with 1285PS @ 6.9km
DB 1430PS with 1285PS @ 6.8km

ASC 1400PS with 1285PS @ 6.8km
DC 1370PS with 1285PS @ 6.8km

Full Throttle Height performance/MW50 use
ASM 1500PS @ 6.4km
AM 1700PS @ 4km

ASB 1600PS @ 6km
DB 1600PS @ 6km

ASC 1800PS @ 6km
DC 1800PS @ 6km

Rated altitude
AS/ASM 7.8km

A/AM 5.8km

DB/DC 6.8km

ASB/ASC 6.8-6.9km


So the figures clearly stipulate the AS motor is a supercharger alteration to the A motor. Whilst the ASB/ASC motor is a supercharger alteration to the DB/DC motor.
Documentation says the AS was developed by mounting the 603 supercharger to the 605A. One can reliably infer the ASB/ASC was this same method applied to the 605D which was done in 1945, using the figures provided for engine performance between the 605 series in full.

It also makes a great deal of sense, considering the reliability and serviceability issues when applying MW50 boost to the A motor, which were not a problem with the D motor.

But again I must ask, what are your sources for holding such reservations about D motors using 1.98ata?
And a new question, what leads you to think the ASB/ASC are constructed from an A motor base like the AS, rather than the D motor base in current production in 1945? It would seem a rather backwards step would it not?

edit.
I should add for prosperity the stipulation of 603 supercharger fitment lay in the cruising conditon of the ASB/ASC compared to the DB/DC, which is a kilometre higher for the same output.
The D series obviously had a larger supercharger casing than the A series to begin with, which blurs the line between it and the AS, combined with increased flow dynamics through the cylinder heads which can alter performance outputs at altitude as well, hence an easier handling of higher pressures in the standard settings.
The lines between DB/DC and ASB/ASC are really very blurred until you examine cruising condition, where the larger supercharger fitment is clear.

I'm back!

I think you're letting the similar expected performance of the DB605ASB/C and DB605DB/C confuse the issue of base engine type. Both the AS And D engines had the same volume, the same supercharger and used the same rpm and boost settings on the same fuels, so it is to be expected that they would have very similar performance. As for why they would produce a previous version in parallel with a newer variant, the Germans did just that throughout 1944-45. They were using old stock and refurbishing existing stock right up to the end. They built the K- and G-10 in parallel and the DB505A and the DB605AS, as well as the 190A and more potent D. In fact the K-4 entered service a bit before the G-10 did. If the DB605ASB/ASC engines are in fact DB605D variants, then you've discovered something that has escaped notice by some very knowledgeable 109 researchers! :wink:

As for my reservations regarding 1.98 ata and the 605DC, it's known that at the end of January 1945 that 1.98 ata was still not cleared (according to Olivier Lefebvre 1.8 ata had just been cleared for the DB on 14 Jan) and testing still showed reliability, as well as cooling problems. It appears that as of 14 March 45, the DC was still awaiting clearance for 1.98 ata, but I don't belive I've seen a definitive translation of that document. After that, there is no documentation of official service clearance or use. However, there is an OKL document that outlines some proposed changes to gruppen equipment in late March that shows four gruppen of K-4's that are to use C3 fuel and 1.98 ata. Few of the changes listed (conversion to 190D-12s, Ta 152C/H, etc.) were made which isn't surprising considering the state of affairs at that stage. It's quite possible that 1.98 ata was implemented in the last six weeks of the war, but it's also quite possible that it wasn't cleared or used, especially considering the state of the Luftwaffe in late March. Hence my reservations.

Brent

[vanir]

Well I should think whether you refer to the ASB/ASC as D series modifications to the AS engine rather than AS modification to the DB/DC hardly makes a difference.
A historian would list the A series, AS series and D series like this:
A, AM
AS, ASM, ASB, ASC
D, DM, D-2, DB, DC

Where I come from a mechanical approach. We would list the A and D series as follows, and wouldn't even recognise an AS series as distinct.
A, AM, AS, ASM
D, D-2, DB, DC, ASB, ASC

One follows the paper trail, the other follows mechanical description. Very similar things happen when documenting automotive technologies. You get one version in commercial print, you get the other in workshop handbooks.

AS is just a 603 supercharger fitment. AS describes 603 supercharger fitment to the 605 motor.
D is a wide series of internal changes and its own supercharger fitment.
Ergo ASB/ASC is both, this is the only leap I've made and it follows direct inferrence from documentation, both figures and statements to the letter. AS=603 supercharger. Performance outputs clearly outline a commonality with the DB and DC and most definitely not with the AS or A.

To my thinking an entire engine series called "AS series" has simply been invented without mechanical construction in mind, when for example the AS is clearly stated by Daimler to be a variation of the 605A and this strictly defines a member of the "A series"

I mean I'm going to get stuck on that point a fair bit here. Are we in agreement the 605AS is precisely and no more than a 605A-1 with a 603 supercharger fitted?
I can look up the documentation.