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Old 04-16-2012, 09:30 AM
Kurfürst Kurfürst is offline
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Quote:
Originally Posted by Robo. View Post
Interesting, I always thought that FTH was the main obvious difference between A-1 and Aa versions.

I am not too sure about the develompemt of German superchargers but from what I remember the A-0 (not used in the sim or during the BoB in the 109s) has had FTH of 4000m, then improved supercharger of A-1 made it to 4500m. 601 Aa was at 4000m again with better low alt performance instead. I am bit confused here with what you're saying.

Still, early Merlins had higher FTH than any of the above engines, hence my assumption the RAF had slight advantage at high alt.
It's mind dazzling, I agree.

http://kurfurst.org/Engine/DB60x/DB6...sheets_A1.html
http://kurfurst.org/Engine/DB60x/DB6...sheets_Aa.html

I did check my references. It seems that that Aa had the new type of Lader, it just had higher boosts, which can be maintained to lower altitudes only of course, and so seemingly the high altitude performance is worse than A-1 with new Lader.

However checking the power curves show that the A-1/new Lader has very similiar, practically the same altitude performance.



ie. at SL

DB 601A-1 with old Lader: 990 PS (1.3 / 2400 rpm), 1100 PS (1.40 / 2500 rpm)
DB 601A-1 with new Lader: 990 PS (1.3 / 2400 rpm), 1100 PS (1.40 / 2500 rpm)
DB 601Aa: 1045 PS (1.35 / 2400 rpm), 1175 Ps (1.45 / 2500 rpm)
DB 601N: 1175 PS (1.35 / 2600 rpm)

Merlin III: 880 HP (+ 6 1/4 lbs / 3000 )
Merlin III: 1180 HP (+ 12 lbs / 3000 )
Merlin XII: 990 HP (+ 9 lbs / 3000 )
Merlin XII: 1165 HP (+ 12 lbs / 3000 )

So at SL the Aa is a bit more powerful, the Merlin can only keep up with 100 octane.

4.5 km - this is the FTH of the A-1/new Lader

DB 601A-1 with old Lader: 960 PS (1.3 / 2400 rpm)
DB 601A-1 with new Lader: 1020 PS (1.3 / 2400 rpm)
DB 601Aa: 1000 PS (1.35 / 2400 rpm)
601N, Emil version with lower FTH: 1050 PS

Merlin III: 1015 HP (+ 6 1/4 lbs / 3000 )
Merlin III: 1080 HP (+ 12 lbs / 3000 )
Merlin XII: 1140 HP (+ 9 lbs / 3000 )

Essentially there is very little difference between these engines at the most common BoB fighting height, the 601A with the old lader is a bit poorer, the others are essentially the same. The Merlin XII is the best for these altitudes.

at 7 km (23 000 feet)
DB 601A-1 with old Lader: 705 PS (1.3 / 2400 rpm)
DB 601A-1 with new Lader: 750 PS (1.3 / 2400 rpm)
DB 601Aa: 725 PS (1.35 / 2400)
601N, Emil version with lower FTH: 920 PS (1.35 / 2600)

Merlin III: 780 HP (+ 6 1/4 lbs / 3000 )
Merlin XII: 830 HP (+ 9 lbs / 3000 )

So if we go higher we find the 601A with the old Lader was not competitive, but the new one was practically the same as the Merlin III.

Te rare Merlin XII and 601N trump all the others, the 601N being the best engine at altitude by far.

Quote:
Originally Posted by Robo. View Post
DB 601Aa - this had increased boost pressures, which meant it developed about 10% more power than the 601A-1 below rated altitude, operating at 1.35/1.45ata instead of 1.30/1.40 ata, but similiar altitude performance. I believe this is the variant we have modelled.

The DB 601A we've got in game is appartently modelled at 1020PS so I suppose it's the A-1 version with FHT at 4500m.

We haven't got this one modelled (perhaps better to compare with Merlin XX at slightly later stage of the conflict), there are no E-4/N (or E-7/N) or Hurricane Mk.II in the sim.
I was going by the 1.35/1.45ata rating, which would point to the Aa. 1020 PS may well point to the A-1 however, its the A-1's rating at altitude.

I haven't seen the data files myself however, just one post on the board. Can you PM me how to extract these? Thx!
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Il-2Bugtracker: Feature #200: Missing 100 octane subtypes of Bf 109E and Bf 110C http://www.il2bugtracker.com/issues/200
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