Bug 174 on 12lbs boost. Review please.

[Kwiatek]

Originally Posted by CaptainDoggles

Sadly I think getting that answer out of them might be difficult. The "afterburner" function in-game ( ) doesn't last anywhere close to 5 minutes, so I would guess they're interpreting it as the 1-minute "increased short-term performance".

It is easly readable on ATA guage where it show after WEP button - 1.45 Ata power - so 1 minut take off power.

Moreover most know German and other county test for serial 109 E planes are very close and showed 467 km/h at deck for 1.3 Ata power ( 5 minute emergency power). So for 1.35 Ata it should be just little faster - a few kph.

Kurfurst think that 109 E was such fast like 109 F-2 but if he belives that Emil has similar speed like more aerodynamical cleaning plane with better enginehe is really not serious man for me

[Kurfürst]

Originally Posted by Kwiatek

Moreover most know German and other county test for serial 109 E planes are very close and showed 467 km/h at deck for 1.3 Ata power ( 5 minute emergency power). So for 1.35 Ata it should be just little faster - a few kph.

I have already explained that the test you have showned are undoubtedfully showing only Hoehenlader performance (ie. for our English friends using FS gear - that was optimized for high altitudes - for all altitudes, and it will naturally show lower results at low altitude.)

Kurfurst think

Correction: Messerscmitt AG thinks that, based on flight test results. And it was so certain about that contracted for about 4000 planes at around 50 000 Reichsmarks each, all reaching 500 km/h at +/- 5% tolerance. That means that Messerschmitt AG would loose about 50 000 Reichsmarks on each 109E that did not reach at least 475 km/h, the absolute minimum. The one the French tested reached about 485 iirc, albeit at only 1.3ata.

that 109 E was such fast like 109 F-2 but if he belives that Emil has similar speed like more aerodynamical cleaning plane with better enginehe is really not serious man for me

The 109E was not as fast as the F-2, the F-2 was rated iirc around 515 kph, the E-1/3/7 at 500 kph. The major difference is not only the engine, or the aerodynamics, but also the propeller. The Emil had a very different propeller one with larger diameter, and had distinctly different propeller effiency than one mounted on the F-2. Even between later G-14 and G-14/AS (different propellers) there was about 10 km/h difference in favour of the G-14 with a low-medium altitude propeller at low altitudes, despite both aircraft having exactly the same amount of power available - 1800 PS.

As for the 109F's aerodynamically more favourable shape, yes it was but it seems its rather overrated. Much of the higher top speed came from the fact that the 601N fitted to the F-2 had much much better altitude output than the 601Aa in the Emils. My studies indicate that the aerodynamic improvements amounted alone for about 15-20 km/h top speed (which is BTW excellent for an aerodynamic improvement)increase, the other 20-25 km/h was entirely down to the increased engine outputs and as noted, the new propeller.

It's hardly a unique situation anyway, the early Spit Vs were much slower than Spit Is at low altitudes, early Spit IXs were again slower than the latest (uprated boost) Spit Vs at lower altitudes etc. High altitude performance was more important for everyone, and propellers can't be just as good in both dense air (low altitude) and thing air (high altitude).

But you know what write a letter to MBB and tell them that you do not like their precedessor's 1940 specs at all.

[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.

[CaptainDoggles]

Originally Posted by 41Sqn_Stormcrow

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.

That's actually a pretty interesting idea for online wars.

[Kurfürst]

Originally Posted by 41Sqn_Stormcrow

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.

I was just thinking about the same thing!

[DD_crash]

This might be a dumb question but has anyone asked the question of 100 octane availabiliy during BoB at the Imperial War Museum at Duxford?