Author Topic: WEP (in)fidelity (Read 438 times)

Jochen · « **on:** August 24, 1999, 08:37:00 AM »

How accurately WEP or other performance improving devices will be modeled in different planes?

For what I know, USAAF used water injection and Luftwaffe water/metanol injection MW-50 in low altitude and GM-1 in high altitude. Luftwaffe also used extra fuel injection to charger inlet to increase power of BMW 801 radials in FW 190F series below 1 km. All these gave somewhat significant increase in the performance region it was designed.

Ordinary WEP was (or I think so) the last several centimeters of throttle, giving the maximum power without any special devices.

The other game has only a generic WEP which is not very accurate representing some combinations. Many real planes had WEP and in addition to this MW-50, GM-1 or similar device. In the other game, when you apply WEP you might use performance improving device or not. To this day, it is not fully clear what kind of devices were modeled in Bf 109G-6 or in all Fw 190 series planes.

MS CFS has pretty accurate WEP modeling and some simulations under development will propably model these things too. I hope that AH will not be any worser.

------------------
Obfr. jochen 'Stern von Afrika' 2./ Jagdgeschwader 27 'Afrika'

Windle · « **Reply #1 on:** August 24, 1999, 11:34:00 AM »

Another point of interest are superchargers. The F4U for example has a 2-stage supercharger set manually for 'neutral' or 'low & high blower', this working in concert with water/methanol injection. I'm curious wheter the blower power will be built into the standard throttle control with the switch from low to high blower occurring automatically at altitude, or wheter it will be a manual feature (the latter preferred).

Also the 5 minute WEP standard in the other game was very general and incorrect in many cases. I've heard stories about WEP being used from 20 minutes up to an hour before having to be disengaged. Of course the terrains are scaled down and I could see the water/methanol limits being applied here but shouldn't actual WEP (full throttle) be limited only by engine temp? Say, unusable during overheat (red light) + 2 minutes for proper cooling? It could be modeled as 'unavailable' or the user could push it and risk engine malfunction (the latter making for better gameplay).

All in all I'm eager to see how you guys work this one out. It's gonna be a real blast to play with the final product regardless.

------------------
Windle
*Future* Aces High VF-17 'Jolly Rogers' 8X

shdo · « **Reply #2 on:** August 24, 1999, 07:02:00 PM »

just FYI,

at least on the U.S. birds most of those blowers were manualy set thus in a combat situation you could have been at 20,000 feet in 'high' blower when you either chased someone down or were chased down. the result? very high manifold pressures that could and would blow your engine and your cooling (if water cooled) before you had a chance to do anything about it.

shdo

Jochen · « **Reply #3 on:** August 25, 1999, 03:22:00 AM »

Quote

I've heard stories about WEP being used from 20 minutes up to an hour before having to be disengaged. Of course the terrains are scaled down and I could see the water/methanol limits being applied here but shouldn't actual WEP (full throttle) be limited only by engine temp? Say, unusable during overheat (red light) + 2 minutes for proper cooling?

If my memory serves me right, Fw 190 was able to use MW 50 for 20 minutes continuously and it had enough methanol/water for 40 minutes. In small arena that translates to pretty serious performance advantage, basically you can fly with WEP all the time.

Here is the key question:

Will the planes be tuned only to arena use similar the MA in the other sim or are they modeled 100% correctly to suit scenarios?

If the main target is arena use, some detuning of planes could be done to achieve balance since everybody can fly what they want. If some plane becomes too good for its timeframe, everybody will fly it. To achieve some variety, performance of planes could be made more equal than it was in WW II.

On scenarios, plane type ratios can be controlled and even 'superior' planes can be used but in smaller numbers.

I would like to hear comments about this from designers.

------------------
Obfr. jochen 'Stern von Afrika' 2./ Jagdgeschwader 27 'Afrika'

Pyro · « **Reply #4 on:** August 25, 1999, 09:39:00 AM »

WEP duration is treated fairly generically for gameplay purposes. Most planes were only rated for 5 minutes or so, but that doesn't necessarily mean their engines couldn't handle longer periods. We don't have to deal with aircraft maintenance, so there's nothing to stop us from abusing our planes without imposing some artificial limitations. In the real world, a pilot who treats his plane like a rental car will suffer much ire from his maintenance crew, engineering officer, and ultimately his commanding officer.

The differences between emergency power and other systems like water injection are modeled.

------------------
Doug "Pyro" Balmos
HiTech Creations

indian · « **Reply #5 on:** August 25, 1999, 11:35:00 AM »

PYRO how about some maintenance problems as in over revving the engine for to long of a duration. Make us fly the planes not ride and kill in them. Speeking of killing the creators guns will be turned down once online wont they say at least to 5%.

------------------
Tommy (INDIAN) Toon

http://www.geocities.com/~tltoon

fd ski · « **Reply #6 on:** August 25, 1999, 12:51:00 PM »

Jochen, do you remember the whole debate on the subject of red stripe on the 109's gear ?
Ik wrote that it indicated to the ground crew that that 109 has GM1 installed which requires 100 octane gasoline.
If you read the history you will know that gas was about as common in LW as snow Etiopia.

So if we are gonna get into "somewhat avaiable" advancements i want spit 9 modified with used 150 octane gas and could run with mustangs...

------------------

Bartlomiej Rajewski
S/L fd-ski Sq. 303 (Polish) "Kosciuszko" RAF
www.raf303.org

Jochen · « **Reply #7 on:** August 26, 1999, 01:52:00 AM »

Quote

Jochen, do you remember the whole debate on the subject of red stripe on the 109's gear ?

Ik wrote that it indicated to the ground crew that that 109 has GM1 installed which requires 100 octane gasoline.

If you read the history you will know that gas was about as common in LW as snow Etiopia.

So if we are gonna get into "somewhat avaiable" advancements i want spit 9 modified with used 150 octane gas and could run with mustangs...

Oh, you got it wrong:

109's with the MW 50 system used 96 or 100 octane C3 fuel, and had the landing gear legs painted red in order to remind the ground crew of the fuel requirements (87 octane fuel would ruin the engine).

It was MW 50 that was indicated by red landing gear struts. I don't have info about GM-1 and it's fuel requirements.

Sure, in the end of the war, LW was having serious fuel supply problems. Despite reading many books about this era, I haven't found indication that 100 octane fuel supply was considerable lower than any other fuel. Care to give your source for this info?

When MW 50 and GM 1 were taken to use, fuel situation was considerable better.

I have impressions that 150 octane fuel was mainly used in planes which chases down V-1's?

------------------
Obfr. jochen 'Stern von Afrika' 2./ Jagdgeschwader 27 'Afrika'

-ik- · « **Reply #8 on:** August 26, 1999, 02:00:00 AM »

that was MW 50 fd-ski, not GM-1.

GM-1 boost was widely used in the 109 series from the E-7 on, and did not require 96 or 100 octane fuel. I have always read that MW 50 required 96 or 100 octane, C3 fuel. However just recently funked had an inquiry with this RAF historian who said records indicate MW 50 could be used with 87 octane fuel too. That would explain why I have never seen a picture of a 109G-6 with a C3 octane rating instead of 87, even though we know MW 50 was used in the 109G-6 (Erich Hartmann wrote about requesting MW 50 kits for his gruppe's 109G-6's because Russian aircraft had become more formidable). We need more research on MW 50, but we can be positive that GM-1 was widely used in the 109G-6.

------------------

[This message has been edited by -ik- (edited 08-26-1999).]

funked · « **Reply #9 on:** August 26, 1999, 06:37:00 AM »

MW-50 didn't require any special fuel.

But MW-50 was used as an anti-detonant to enable increased manifold pressure. By definition, higher octane gas also enables increased manifold pressures without detonation.

The octane requirements were based on the MP that the engine would be run at during MW-50 usage.

I'm not getting this from a Luftwaffe source, this is just how you use methanol-water injection. My dad did his thesis on turbosupercharging and methanol-water injeciton.

[This message has been edited by funked (edited 08-26-1999).]

juzz · « **Reply #10 on:** August 26, 1999, 11:05:00 AM »

Of course, those engines (DB605ASOM?) using MW-50 and hi-octane (93?) fuels didn't last very long, and used heaps more fuel too

I imagine those Spit MkXIV's running 25lbs boost/150 octane fuel had short engine life too.

fd ski · « **Reply #11 on:** August 26, 1999, 12:37:00 PM »

Never really liked fishing... but it looks like I have potential..... talk about stirring up the nest

Jochen - to answer your questions - 100 octane aviation gas was widely avaiable for Allies for US- on the other hand Germany had trouble GETTING enough gas not to mention redefining it...
I'm at work now and don't have books here, but i'll look it up. I remember reading that LW aircraft performance would be somewhat better then normal had they had gas Allies used... but they didn't...

------------------

Bartlomiej Rajewski
S/L fd-ski Sq. 303 (Polish) "Kosciuszko" RAF
www.raf303.org

-ik- · « **Reply #12 on:** August 26, 1999, 12:50:00 PM »

Jochen · « **Reply #13 on:** August 27, 1999, 01:52:00 AM »

Quote

Never really liked fishing... but it looks like I have potential..... talk about stirring up the nest

Heh, I tried same thing in A.G.W with Spitfire Mk.IX c and e wing, it worked great

I try to build up patience and dicipline not to reply all 'suspicious' posts but it's hard to know when one is serious or is he just fishing.

Oh, btw Pyro, does AH Spit IX have early c wing or later e wing? And what is availability of negative G devices in early Mk.V's and Mk.IX's?

<smack> ouch!

just kidding fd-ski, just kidding

Quote

Jochen - to answer your questions - 100 octane aviation gas was widely avaiable for Allies for US- on the other hand Germany had trouble GETTING enough gas not to mention redefining it...

I'm at work now and don't have books here, but i'll look it up. I remember reading that LW aircraft performance would be somewhat better then normal had they had gas Allies used... but they didn't...

This was surely the case in late war. But I almost can bet that in early war LW had better fuel situation than RAF because Germany had Romanian and southern russia oilfields and their refineries were pretty much intact. On the other hand RAF and Britain were under strict sea blockade and their own oil refineries were bombed to tiny bits.

Oh those happy days for Lufwaffe...

------------------
Obfr. jochen 'Stern von Afrika' 2./ Jagdgeschwader 27 'Afrika'

Bombjack · « **Reply #14 on:** August 27, 1999, 05:13:00 AM »

Quote

This was surely the case in late war. But I almost can bet that in early war LW had better fuel situation than RAF because Germany had Romanian and southern russia oilfields and their refineries were pretty much intact. On the other hand RAF and Britain were under strict sea blockade and their own oil refineries were bombed to tiny bits.

Oh those happy days for Lufwaffe...

Oops! Nearly hooked me there.

------------------
-----------
-bmjk-
617 Squadron RAF