#41
|
|||
|
|||
Quote:
Just think about it: It is not possible to achieve +12 boost above FTH, why put a restrict on a boost for an altitude where this boost is not possible? But enough of Spitfire talk, this topic is about Bf 109. Last edited by 41Sqn_Banks; 10-10-2012 at 07:10 PM. |
#42
|
||||
|
||||
Just reading and summarising the information in this thread, ideally there would be both engines modelled:
DB 601Aa for E-3/B, E-4/B (and E-7 eventually) DB 601A-1 for most of the other Emil variants, especially without bomb racks installed (E-1s, E-3s and E-4s in the sim) It is known that due to overhauls and re-builds, there were all combinations possible and I am not taking the superchargers in account. Only cca 3 out of 10 DB 601s made were Aa. DB 601Aa = full throttle height of 4000m, rated at 1,35 ata (1,45 max) DB 601A-1 = full throttle height of 4500m, rated at 1,3 ata (1,40 max) Looking at the above, the only DB601 modelled in the sim has got the rated power of Aa and fth of A-1. Quote:
Quote:
__________________
Bobika. Last edited by Robo.; 10-10-2012 at 07:47 PM. |
#43
|
|||
|
|||
Salute
There is also this document, dated 24/7/1942 according to Mike Williams site where it is located. It indicates a much more conservative speed than some of the previous documents. I am also very interested in any German speakers interpretations of the following three documents, dated August of 1940, also found on the WWII Aircraft Performance site: |
#44
|
|||
|
|||
Quote:
The below document, dated October 1940 by the WWII Aircraft Performance site is from the manual I have already posted, (http://www.scribd.com/doc/32387854/Handbuch-DB-601-A-B) ...and indicates the DB601A and B had both variants of superchargers installed, both the 'Neuer' and 'Alter' lader, but the limit for both was 1.40 for takeoff and 1.30 for 5 minutes. By the way, can anyone shed any light on the methodology to convert the German method of measuring boost, ie. 'ATA' to 'Ft/pounds', or 'Inches of Mercury'. Last edited by *Buzzsaw*; 10-10-2012 at 08:26 PM. |
#45
|
|||
|
|||
Salute
And one more. The following document is only really relevant to the 109E-1, although it does show the E-3 weights, which by the way indicate that game aircraft is underweight. The primary use of it is that it shows production E-1 speeds at 1.15 ata boost, ie. continuous cruising speeds. Measurements could be taken at this boost level to determine if the aircraft meets these specifications. |
#46
|
||||
|
||||
Quote:
I simply don't know so I did not consider the various supercharger combinations at all in my original post. It is obvious though that in case we have the Aa modelled, the FTH is wrong. 1 ata = 1kg/cm^2 = 14.2 lbs/in^2 = 28.96 inHg
__________________
Bobika. |
#47
|
|||
|
|||
Quote:
Motorunterzetzung DB 601 A = 1:1.55 Reduction gear ratio DB 601 A = 1:1.55 1 ata = 1 kg / square centimeter. I am not going to convert this to PSI (0.454 kg = 1 lbs, 2.54 cm = 1 inch, have fun ) but keep in mind the British used relative boosts, ie. (+) 0 PSI = 1 ata, and + 6.25 PSI boost on the Merlin III is 1 ata plus whatever 6.25 PSI is in ata. Bottomline, the Merlins always used much higher boost than DBs to compensate for smaller displacement. IIRC the 1.7 ata boost of the methanol boosted 605AM was something like +7 PSI..
__________________
Il-2Bugtracker: Feature #200: Missing 100 octane subtypes of Bf 109E and Bf 110C http://www.il2bugtracker.com/issues/200 Il-2Bugtracker: Bug #415: Spitfire Mk I, Ia, and Mk II: Stability and Control http://www.il2bugtracker.com/issues/415 Kurfürst - Your resource site on Bf 109 performance! http://kurfurst.org |
#48
|
||||
|
||||
Quote:
Problem is, we are end of the development line, and 1c certainly not going to give us 3 seperate variants. The only diffo between the A and Aa is probably that the latter is maybe about 10-15 km/h faster down low. Quote:
Quote:
Quote:
__________________
Il-2Bugtracker: Feature #200: Missing 100 octane subtypes of Bf 109E and Bf 110C http://www.il2bugtracker.com/issues/200 Il-2Bugtracker: Bug #415: Spitfire Mk I, Ia, and Mk II: Stability and Control http://www.il2bugtracker.com/issues/415 Kurfürst - Your resource site on Bf 109 performance! http://kurfurst.org |
#49
|
||||
|
||||
I believe he refers to the second (bottom) part of that document titled Reichweiten where we see the speeds at 1,15 ata Dauerleistung at 1, 3, 5 and 6km altitude (only 0,92 ata achievable at 6km) so I guess he was right in his assumption.
__________________
Bobika. |
#50
|
|||
|
|||
Quote:
You are suggesting this is a test of a different reduction gear? Because in fact the speeds shown are achieved at a boost of 1.15 ata. |
|
|