Originally posted by MiloMorai
The K-4 @ 1.98 should be a perked a/c. Compared to the number of K-4s @ 1.80 it was only 'penny pocket' in numbers.
There`s information on 1.98ata(2000HP) K-4s/G-10s on my site :
http://www.kurfurst.atw.hu/Briefly,
OKL, Lw.-Führüngstab, Nr. 937/45 gKdos.(op) 20.03.45 and
Niederscrhrif Nr. 6730. Daimler-Benz AG, Sektor Entwicklung. 20.1.45 shows that a single Gruppe, II./JG 11 converted to 1.98ata for operational testing in January 1945, with four other Gruppe employed on the Western front, ie. I./JG 27, III./JG 27, III./JG 53, IV./JG 53, converting to 1.98ata in March 1945.
Each Luftwaffe Gruppe (=Wing) would contain 3-4 fighter squadrons (4 Gruppe => 12-16 Squadrons), with a Gruppe`s typical established strenght of 68 aircraft (inc. reserves) at that time.
LW strenght reports show for these last four Gruppe as per 9th April 1945 that
142 examples of G-10/K-4s were effected with the boost increase of 1.98ata, 79 of them being servicable at the time.
Considering the operational numbers of the perked Spitfire XIVs (5 Sqns, plus two recces for about 60-80 aircraft), it seems feasible to perk the 1.98ata 109K-4s and the Mk XIVs, leaving the basic 1.8ata K-4/G-10 a non perked plane, as it was quite widespread in the Luftwaffe (1700 being produced of K-4, 2600 of G-10).
Ie. bf 109 strenght 31 Jan 1945, first line units only :
Bf 109 G-6 : 71
Bf 109 G14 and G-14/U4 : 431
Bf 109 G-10, G-10/U4 and G-14/AS :568
Bf 109 G-10/R6 : 51 (bad weather version)
Bf 109 K-4 : 314
1435 Bf 109s
So 314 K-4s at the time Jan 1945, ca every 4th Bf 109 was K-4, probably increased further (Dec 1944 there was 200).