Bug 174 on 12lbs boost. Review please.

[41Sqn_Banks]

There was no WEP for DB601 A1/Aa, only a special take-off boost. There is nothing that indicates that 1' Minute 1.4/1.45 was used for anything else than take-off or above 1-1.5 km altitude.

http://www.il2bugtracker.com/issues/40#note-10
http://www.il2bugtracker.com/issues/40#note-11

[CaptainDoggles]

Kwiatek, are you just really good at keeping the stick level or is there a trick? I want to test at FTH but I have trouble keeping the aircraft steady.

Maybe I need to decrease sensitivity on my trim controls.

[Osprey]

Try not to move your hand so much. I realise that it's so used to vigorous movements that it's tough for you, but I reckon you can manage it if you concentrate enough.

[CaptainDoggles]

Are you upset that I called you out for trying to misrepresent a historical quote?

[Kurfürst]

Originally Posted by 41Sqn_Banks

There was no WEP for DB601 A1/Aa, only a special take-off boost. There is nothing that indicates that 1' Minute 1.4/1.45 was used for anything else than take-off or above 1-1.5 km altitude.

http://www.il2bugtracker.com/issues/40#note-10
http://www.il2bugtracker.com/issues/40#note-11

On the other hand there is nothing to suggest that 1,40/1,45 ata was not possible use at any altitude. So far I have not found any evidence that this was mechanically restricted to the 1st supercharger speed, and it quite likely that it was not.

OTOH I agree that the manuals insist that is to be used for special take off conditions. Which is kinda parallel to the Spitfire II limitations (which limit +12 to take off conditions only), so it just might be good idea to include a code that this 'WEP' on both planes should be only usable when the wheels are on the ground.?

[41Sqn_Banks]

Originally Posted by Kurfürst

On the other hand there is nothing to suggest that 1,40/1,45 ata was not possible use at any altitude. So far I have not found any evidence that this was mechanically restricted to the 1st supercharger speed, and it quite likely that it was not.

OTOH I agree that the manuals insist that is to be used for special take off conditions. Which is kinda parallel to the Spitfire II limitations (which limit +12 to take off conditions only), so it just might be good idea to include a code that this 'WEP' on both planes should be only usable when the wheels are on the ground.?

The take-off boost in Spitfire II was provided by a "gate control" which caused a fixed throttle valve setting, thus boost would fall off quickly with altitude (the throttle valve didn't open progressively to maintain the take-off boost)*.
The boost control cut-out on the other hand opened the throttle valve progressively to kept the +12 boost until it was completely opened, thus emergency boost was maintained up to FTH.

The DB601 manual indicated that for the take-off power the throttle valve is opened slightly more than under normal condition. This would theoretically allow to use 1' Minute boost up to FTH.

* with increasing altitude the throttle valve would again open progressively to keep +9 boost as the throttle lever is logically in the most forward position, but as we know it should only be used up to 1,000 feet this would normally not occur.

[Kurfürst]

Thx for the explanation, Banks. Regardless of the lack of mechanical restriction on the 109E, I think our virtual selfs should be limited by what was authorized and how. At least the manuals set these limitations out in clear-cut manner to which I believe most pilots had adhered.

Otherwise its a very swampy terrain we are heading. Field mods this, field mods that, weren't really followed in the field, yes it was, no it wasn't.. you get the point.

[41Sqn_Banks]

I think the only bad thing that would happen in the DB601 is excessive engine wear, much like the use of take-off or emergency power for Merlin engine.

The explanation for Gate control comes from: http://www.enginehistory.org/Piston/...erlinABC.shtml

Agreed about the virtual limitation. It would be the best if take-off boost settings simply wouldn't provide a increased boost above their limiting altitudes. The engine seems to be able to handle this, as can be seen in the speed graphs of Blenheim and Fiat G.50 (I didn't test so far what happens if take-off boost is used above that altitude in these planes).

Alternatively engine damage could be forced above these altitudes, much like the GM-1 restriction from old IL-2. But I guess this would be incorrect in most cases.

[klem]

It seems to me that the historically available boost/overboost capabilities should be modelled for all aircraft whether their use in any particular circumstance was authorised or not. Any pilot having the need to save his backside would use whatever was available to him, authorised or not, and I can't see Dowding, Park, Molders, Galland or anyone else ripping into a pilot for damaging his engine to save his life.

CEM should be used to damage the engine if the prescribed time limits, or perhaps an increased % of the time limits like 125%, were exceeded as that is the only way we have of bringing some kind of limitation to its use and representing engine damage. CEM already does this to Merlin engines if max boost and rpm are maintained for too long although I haven't tested what those limits are.

When we have finally a reasonable scoring system online and a reasonable career mode I'd suggest that all pilots violating engine wear limits get penalties on online score and career progress offline.