The K-4 used 1.98 ata operationally. I guess that you'd also want the 109 boost to be modelled to 1.98 as well, right?
And by the way, what's your game ID?
The K4 never used 1.98ata operationally except in testing, and it did not find favor. The only document ever shown that might support the idea is a document kurfurst likes to wave about, one dated 20march45, that is clearly a statement of intent and not a operational order. The document also refers jet upgrades and other things that are known to have not happened. There is also zero pilot accounts or maintenance logs etc to support its use operationally. All that is known for certain is that it was tested, and rejected. If there was ever any re-attempt to use it operationally there is no definitive documentation to support it. And as a side note, even if it was proven, which it is not, it would not have happened till the last month of the war....which is hardly significant and does not warrant use in game.
"No evidence has come to light proving operational use of 1.98 ata by combat units, however, its clear from surviving documentation that the Luftwaffe felt a pressing need to increase the performance of the 109 and that 1.98 ata was tested and proposed for use. Prien & Stemmer have written about the desperate situation confronting the Luftwaffe in 1945:
The start of the Russian offensive (note: in mid January 45) resulted in the biggest regrouping of forces by the Luftwaffe since the invasion of the Soviet Union. From this point on, the course of operations in the east dictated the employment of all remaining forces, especially of the air units and the flak. Russian breakthroughs everywhere threatened the very existance of the Reich. Faced with this, the German command reduced defensive operations in the west to a minimum, while the Defense of the Reich was virtually abandoned.
The only units left in action over the west were JG 2, 26, 27, and 53, which operated mainly against the Allied fighter-bombers and twin-engined bombers but not against incursions by the heavy bombers.
A Wehrmacht Operations Staff memo dated 19/1/1945 stated that “a high degree of forces are to be concentrated for the great decisive battle in the eastern theater at the conscious acceptance of the associated serious risk in the western theater”. For the air defense that meant that the flak would bear the main of subsequent defensive operations in the west, while the bulk of the flying units were to be deployed in the east to support the army. To this end the units deployed in the east were to receive prioity in the allocation of the last remaining reserves of fuel. The memo went on to say: "The available fuel is to be allocated accordingly”.
As a result of increased consumption in defensive operations in January and February the fuel shortage had again become acute, and on 4 March 1945 the OKW saw itself forced to issue another directive on future Luftwaffe operations. It decreed that apart from operations by the few jet fighter units, defensive missions against incursions over the Reich by the American and British heavy bombers were now to be halted completely, which nearly meant the end of the Defense of the Reich. There was also a rigorous concentration of remaining forces for operations in the east, in order to make the defensive effort there as effective as possible.
By now deliveries of aircraft had slowed down, which is why, for example, that in March III Gruppe was given a number of old BF 109 G-6s (probably from disbanded training units) in addition to several BF 109 K-4s and G-14s. (Note: Prien has also written that II./JG 53 reverted to old Bf 109 G-6's)
War Diary Luftflotte 6; worthy of note is a note dated 3/4/1945 in the collection “Fuel Situation 1945” which says: “Production of the BF 109 has been halted, six Gruppen in Luftflotte 6’s command are being disbanded immediately in order to create a reserve”. The effected units were I/JG 3, I/JG 4, III/JG 6, II/JG 51, I/JG 53 and III/JG 77. Units were disbanded in the same way by the Luftflotte Reich (IV/JG 301) and Luftwaffe Command West (IV/JG 27). 42
II./JG 11, the Me 109 unit that had earlier experimented with 1.98 ata, also disbanded during the first few days of April:
An den ersten sechs Tagen im April war das JG 11 nicht im Einsatz; nicht etwa schlechtes Wetter, sondern allein der anhaltende Treibstoffmangel verhinderte ein Eingreifen des Geschwaders in das Geschehen an der Oderfront, an der es im übrigen während ruhig blieb. Offensichtlich erfolgte in diesen Tagen die Auflösung der II./JG 11, deren Flugzeugführer danach zum Teil auf die I. und III. Gruppe verteilt wurden, während einige der erfahreneren und erfolgreichen – darunter Hptm Rüdiger Kirchmayr, Olt. Erich und Lt. Walter Köhne – zu dem Strahlerverbänden versetzt wurden. Für viele der jungen, unerfahrenen Flugzeugführer, die zur Katagorie “C” zählten, endete dagegen der Einsatz in einem fliegenden Verband und sie fanden sich in Fallschirmjäger – oder sogar Waffen-SS Einheiten wieder, um dort als Fussoldaten noch eine Verwendung im Sinne des “Führers” zu finden; mit ihnen gingen eine ganze Anzahl von Männern des Bodenpersonals, deren Stellen durch die Auflösung der II. Gruppe entweder überflüssig wurden oder die durch weiteres weibliches Personal ersetzt wurden. 43"
"Aspera G.m.b.H., Kamenz on orders from OKL Chef TLR F1. E. 3 V reports in Geschwindigkeitmessungen mit 4 VDM Luftschrauben auf Me 109 K4 mit DB 605 D dated 4 January 1945 that full measurments could not be reported due to engine damage at 1.98 ata. Trotz mehrerer Stunden schonenden Einfliegens des Motors mit Dauerleistung vor den Messreihen mit Kampfleistung stellte sich bei den ersten Prüfläufen nach der Umstellung auf p = 1,98 ata ein Motorschaden heraus, der einen Motorwechsel notwendig machte. 35
Interner Aktenvermerk Nr. 6642 from Daimler-Benz (internal memo) dated 17.1.45 reports on a meeting held 10 January 1945 at OKL, Berlin. All 4 DB 605 DC engines supplied to Rechlin from DB-Genshagen failed (pistons, piston rods, supercharger), therefore special emergency power DC (1.98 ata boost pressure) for the troops is not released (die Sondernotleistung DC (1,98 ata Ladedruck) für die Truppe nicht freigegeben). 36
Niederschrift Nr 6717 from Damiler-Benz, dated 19.1.45, states that DB 605 D engines from Kassel are delivered at 1.80 ata boost with B4 and Mw 50. Die Motoren DB 605 D werden in Kassel allgemein mit Ladedruck 1,80 ata mit B4 und Mw 50 abgenommen. 37
Niederschrift Nr 6730 of Daimler Benz dated 24 January 1945 details discussion at a conference held 20 January 1945 in the office of the Chief engineer of the Luftwaffe in Berlin: It states that testing of 1.98 boost pressure may be done provisionally at Group 2/11, only engines with 1.8 boost may be supplied and strict punishment is threatened if this instruction is neglected. Also of note is mention of problems due to poor quality fuel as well as a devastating comparison of the Me 109 and the Mustang. 38
Niederschrift Nr 6731 of Daimler Benz also dated 24 January 1945 discusses a meeting held at Rechlin on 16.1.45. Some of the same material is discussed as in Nr 6730, the conclusions being that 1,98 ata is not to be used on the front line. Testing at Rechlin will continue. 39
Messerschmitt's Erprobungsbericht Nr. 15 vom 16.1.45 bis 15.2.45 dated 22.2.45 states that 1.98 ata is blocked, testing done at 1.80 ata: WM 50 Betreib - Nach Mitteilung der E'Stelle sind 1,98 ata gesperrt. Die Erprobung (Funktion und Kerzentemperatur) wird vorläufig mit 1,80 ata (2800 U/min) durchgeführt. 40 "
Courtesy of WW2 aircraft performance.