Author Topic: Spit 16  (Read 11717 times)

Offline Benny Moore

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« Reply #150 on: March 01, 2007, 03:39:04 PM »
Quote
Originally posted by Charge
Depends on the relative change between the two factors. Strange enough the pilots alledgedly considered the A8 to be the best fighter of FW190A breed.


You're missing the point.  If you add power, the airplane will do everything better.  If you add weight, the airplane will do everything worse (except dive).  Any decrease in performance in later Focke-Wulfs is due to weight increases, not power increases.  Quite the opposite, the power offsets the weight.  If you add power without adding weight (which is what raising the rating does), then the airplane will only be better.  Sometime try dogfighting at nine tenths throttle for the whole fight.

Quote
Originally posted by Charge
The expression of "short time" is strange. But in all considering the shortened service life before overhaul I find your statement a bit strange. Although it is possible that the engine requires a high pressure run to to keep clean, but 15 minutes? Maybe the restriction was loosened later on?[/B]


For a P-38J or L, with the drastically improved intercoolers, fifteen minutes is "a short time."  The Allisons themselves were capable of running at 75" for seven hours continuously, according the Vees for Victory, a book about Allison.  Granted, they were not actually in an airplane, and they were fried by the end.  However, it does give us an example of "a long time" from Allison's perspective, from which we can derive that fifteen minutes is a short time.  This is esecially true since pilots were told to run for that time on every flight, whether or not they needed the extra power.
« Last Edit: March 01, 2007, 03:41:18 PM by Benny Moore »

Offline dtango

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« Reply #151 on: March 01, 2007, 10:27:36 PM »
Quote
Originally posted by Krusty
http://www.gonzoville.com/ahcharts/index.php?p1=109k4&p2=109g14

^-- what we've got in-game right now. Climb alone doesn't dictate or reflect boost levels used. Unless you're saying the G-14 has 1.98ata, too?? :t


Edit: I'm not picking a fight. I'm just pointing out the climb isn't part of the equation. Too many variables to simply pin it on boost alone.


1st- rate of climb is absolutely a reflection of power available at a particular boost for a particular engine.  ROC = (T-D)*V/W.  T*V in the equation is thrust power available which is a function of engine power.

2nd- why would I be saying the G-14 boost be at 1.98ata?   The G-10 and K-4 have different engines.  If both planes were at the same boost levels in flight, I wouldn't expect that the engines produce the same power at all because they are different engines.

Tango, XO
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« Last Edit: March 01, 2007, 10:39:12 PM by dtango »
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Offline Knegel

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« Reply #152 on: March 02, 2007, 02:38:24 AM »
Hi  dtango,

Krusty say that the G10 and G14 climb better than the K4 in AH, therefor the K4 cant run on 1.98 ata, but anyway, i still cant reproduce a 4800ft/min climb, all constant climbs i low level made have 4400-4500ft/min as result.

The climb of the 109K for sure is better than the test show, while the speed is rather ok(i did overview your correction, thanks for the hint), but it looks like the climb of the 109G10 and G14 is to good as well.

btw, no tests on Kurfis page seems to be DB605DC + MW50 related!!

At least i would expect a better climb with 200PS more power from sea level to 4900m, not up to 6000m. It seems to me that it realy is the early DB605D + MW50, which had lower rated altitude than the DB605DB and was more similar to the DB605AM.  

The climbrate with a DB605DC + MW50 should decrease MUCH above 4900m altitude, same goes for the speed, but its almost exact the same climb curve like the DB605DB show, but with a less good performence above 5500m.
Also the Vmax in hight, on the DB605D + MW50 sheet isnt higher than that of the DB605DB, only the Vmax at sea level, but as we know from the La7 and other planes, a Vmax different of 10mph from plane to plane, even with the same poweroutput is nothing special(The La7 test i saw vary from 595-616km/h).
I have no doubt that the 109K4 with 2000PS was at least as fast as the La7 at sea level and the climb must have been better than the DB605DB climb up to 4900m.

Imho the currently to good climb of the 109´s is made to overcome the wrong e-bleed formula while turning, used in AH.  The 109´s with their correct climb would be hopeless, same like the P38´s without the flaps would be hopeless. At least i have no idea why the 109K in low level bleed so much more energy than the La7.  
Imho they should adjust the La7, F4U, Temp, 109F, Spit16 and Hurri(and other rather light wingloaded planes) E-bleed behaviour and they should adjust the 109 climbs(maybe other that are wrong??) to the right values.

The static performences, like Vmax, climb etc are not much worth if the E-Bleed dont work like it should.

The default FM´s of "European Airwar" are a good example to display this:
The 109E4 has a Vmax of 550km/h @ sea level and 1000m/min climb, the Spit1a has a Vmax of 470km/h and 800m/min climb.
This static values clearly show a much to good 109E4, but in game the Spit was a absolut even plane, cause like all other rather light wingloaded planes, it simply didnt bleed energy while turning, also not while highspeed turns.

Imho somewhat similar its in AH(not that extreme). Of course the E-bleed at varius speeds and changing speed is not easy to determine in exact numbers, nevertheless the physical law determine the relations.

And i got the impression that the E-Bleed relation often dont fit in AH.
Heavy wingloaded planes(tendency to have a high dragload) like the P38´s and FW190A8, once fast, should keep energy much better than very light wingloaded planes, specialy if this planes have less power as well.

The 109G6 should keep much more energy than the 109F4, but its the other way around.
The SpitIXc should keep more energy that the SpitVb, but its the other way around, etc.
I only know the A6M2 and A6M5 where this relation fit. The more light A6M2 with its bigger wings bleed more energy while speed decreasing turns than the A6M5. The A6M2 also dont have a that good upzoom, but the relation between this two planes work oposide to how it work otherwise in AH.

Heavy planes with relative smal wings and fuselage simply miss the needed surface to slow down as fast as a more light plane with relative big wings.  Although they need a higher AoA to archive the same turn radius than the more light wingloaded(liftloaded) plane, the surface into flight direction still isnt more big than that of the other plane. At highspeed the higher relative inertia and the smaler relatibe zero drag will help to keep the speed up and and if the other plane turn more tight, it should bleed even more energy.

Thats how it work between the Zeros and thats how it should work in all planes. Only if this relation´s fit, its possible to adjust the static performences(climb, Vmax) to a realistic value, without to get a unbalanced gameplay.

How i would like to be able to make a real B&Z in my P47 or FW190A8 or P38, currently this planes only can make hit and run, even vs outdated planes like the 109F4, HurriII or SpitV.


btw, Benny, weight isnt ALWAYS a disadvantage!!! Weight is a storage of energy, when a P38J meet a SpitV with 550km/h in 1000m alt, the P38J keep twice as much energy + twice as much power than the SpitVb and should be able to outzoom it by easy!!!

Wight hinder the deceleration in the same way like it stop the acceleration.

Why the FW190 and P38 have a so slow acceleration but a so extreme deceleration is a miracle for me.

If HT get this right, we can talk about the static performences(i bet then the P38 dont need more than 2x 1600HP).

Greetings

Knegel

Offline dtango

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« Reply #153 on: March 02, 2007, 09:46:28 AM »
Knegel:

Hmm, the Mtt document says the data comes from a DB605DC + MW50.  

2ndly if it was an earlier version of the DB605D then the 1st graph wouldn't make any sense at all.  The power output of the earlier model DB605D's have lower max power output vs. the DC+MW50 engine.

DB605D-2 (C3): 1435 PS
DB605DM (C3 + MW50): 1800 PS

Also the D-2 has a lower output and the DM has about the same power output compared to that of the DB605DB+MW50 (1850 PS).

So if the 1st chart is indeed an earlier version DB605D why are the SL speed and climb rate so much better than the graphs showing the DB605DB+MW50?  So the 1st pair of charts is the same plane but with a lower or equal power output vs. 3rd pair of charts but the plane in the 1st pair of charts has a higher SL speed and better climb rate.  That doesn't make sense.

----
As for the AH ROC figures, the AH charts are showing instantaneous rates of climb.  I'm not sure how you are doing your tests but if you're doing them by averaging them (dividing the total alt climbed by the time to climb) that's why they would be different.  Otherwise the AH charts are incorrect or the weight of the 109K4 you are testing is higher than the weight that the AH charts are generated from.

Tango, XO
412th FS Braunco Mustangs
« Last Edit: March 02, 2007, 09:50:15 AM by dtango »
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Offline Bronk

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« Reply #154 on: March 02, 2007, 10:04:19 AM »
Quote
Originally posted by Knegel
Snip


At 5k the 109K4 exceeds 4800 fpm.
Plug it in here and see for yourself.
http://gonzoville.com/ahcharts/index.php


Bronk
« Last Edit: March 02, 2007, 10:07:26 AM by Bronk »
See Rule #4

Offline Knegel

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« Reply #155 on: March 02, 2007, 01:53:09 PM »
Hi dtango,

once again i made a reading mistake, i thought max climb with DB605D and MW50 is 22,5m/sec, while its 25m/sec.

But anyway, 2,5m/sec also could be a normal fluctuation(look to the different 109G tests we have), 22,5m/sec is pretty low for a 1850PS plane with only 3400kg anyway(compare this with the SpitIXc merlin66 tests and Spit14 tests). With much less powerfull engines and powerloads the 109 airframe did show much better relative results.
Open or closed radiators or a different climb speed can cause such differents.  

It could be the DB605DC on base setting 1.98 ata but using 1.8 ata and 1.9.
This would explain the higher rated alt with MW50 and the only a bit better performence down to sea level, but then thats not the 2000PS of the 1,98 ata.
At least the speedcurve in higher alt is the same like the DB605DC o.MW curve with 1.8ata (7000m 720km/h) and a constant speed gain of only 10km/h(6,2mph) with 150-200PS more power is  also rather strange and also could be normal fluctuation.
Also the curve above "MW50 Abschaltung" is strange, when 1,98 ata got used to 6000m, there should be much less power after dissabling MW50 and the high boost, like we see it in the DB605DB chart. With 1.8 ata this would have been less dramatically like show in the picture. The speed and climb gain could be a result rather of more closed radiators than of a power gain. With 1.8 ata + C3 fuel + MW50, the MW50 could get used only as "Ladeluftkühlung", resulting in a little bit more power, but a more cool engine(less radiator flaps needed).

It also could be the "Leistungsmaschine I" where the testers was refering to, which had a speed gain of 12km/h as result.

Would be interesting to see more background to this test(what ata got used, what radiator flap setting etc).

Greetings,

Knegel

Offline EagleDNY

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« Reply #156 on: March 03, 2007, 02:56:09 PM »
Quote
Originally posted by Krusty
Yes... it's only been "recently" that some folks say we have 1.98ata. Up until now nobody has ever argued this, in fact most said the opposite, and begged/pleaded for 1.98ata to be included in the game.

I don't buy that 1.98ata is modeled, currently.


It ISN'T - we are definitely running the 1.8 model according to the 109K testing I just did.  Take one up to 24,600ft, level it out, wep on and see the top speed.  429 Mil / 445 WEP - that is a 1.80 model (even if you don't believe the boost guage which only goes UP to 1.80...).

Offline Benny Moore

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« Reply #157 on: March 03, 2007, 02:57:46 PM »
So that must mean that it's not got enough drag, then, right?

Offline dtango

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« Reply #158 on: March 03, 2007, 06:39:27 PM »
Quote
Originally posted by EagleDNY
It ISN'T - we are definitely running the 1.8 model according to the 109K testing I just did.  Take one up to 24,600ft, level it out, wep on and see the top speed.  429 Mil / 445 WEP - that is a 1.80 model (even if you don't believe the boost guage which only goes UP to 1.80...).


Both the 1.98 C3+MW50 and the 1.8 B4+MW50 are at 720kph/447mph at 24,600 according to the charts so that's not telling you any difference between the two.  You might try testing it at 19.7K (crit alt for the 1.98 C3+MW50) or at 23.3k (crit alt for 1.8 B4+MW50) to check.

Max top speeds at SL & at Alt suggest that the AH K4 is a very similar to the 1.8ata B4+MW50 version as per the Mtt graphs.  That being said 1.98ata C3+MW50 Mtt graphs max top speeds are similar to the 1.8ata B4+MW50 K4: same top speed at alt (~727 kph/ ~450 mph) but differ by about 8-10 mph at SL with the 1.98ata C3+MW50 at 610kph/379mph.

Climb rate is a different question.  Here's the best ROC comparisons:

AH K4: 4800 fpm @ 4000 ft
1.98 C3+MW50: 4920 fpm @ 2600 ft
1.8 B4+MW50: 4440 fpm @ 2600 ft

The AH K4 has a best ROC more similar to that the 1.98 C3+MW50 version.

Tango, XO
412th FS Braunco Mustangs
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"At times it seems like people think they can chuck bunch of anecdotes into some converter which comes up with the flight model." (Wmaker)

Offline Widewing

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« Reply #159 on: March 03, 2007, 07:33:32 PM »
Maximum speed at best altitude for the AH2 Bf 109K-4 flying with 25% fuel is:

453 mph @ 22,000 feet using WEP.

It does 419 mph at that same altitude in MIL power.

My regards,

Widewing
My regards,

Widewing

YGBSM. Retired Member of Aces High Trainer Corps, Past President of the DFC, retired from flying as Tredlite.

Offline Knegel

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« Reply #160 on: March 04, 2007, 01:35:13 PM »
Quote
Originally posted by dtango

The AH K4 has a best ROC more similar to that the 1.98 C3+MW50 version.

Tango, XO
412th FS Braunco Mustangs


Hi,

for now i dont saw enough datas to say that the DB605D + MW50 sheet is made with 1.98ata. Base setting 1.98 ata dont say that 1.98 ata got used(look to the test without MW50).

At least 12km/h more speed at sealevel would be a real poor gain with 150PS more. The testers wrote that the "Leistungsmaschine I" with its more clean surface etc already did gain this speed and probably also had a better climb. Its a strange chance to see that the test show exact the 12km/h more speed, like the "Leistungsmaschine I" should have had.

I realy believe much, but not that the 109K4 with 2000PS was just as fast as the La7 with 1850PS or that the big and heavy P51B with 75"(around 1800HP??) with wingracks reach 611km/h.

Edit: btw, already 1937 the Bf109V13 with  1660PS did reach 611km/h in an official record trial. So please dont come with a to thick airfoil etc. This plane had the squary wings and the tailwing strutting of the E model.
http://www.adlertag.de/mainindex.htm


Greetings,

Knegel
« Last Edit: March 04, 2007, 01:57:42 PM by Knegel »

Offline dtango

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« Reply #161 on: March 04, 2007, 06:55:27 PM »
Knegel:

I understand where you're coming from.  I thought I would do a quick check regarding Vmax at sea level for the 1.8 B4+MW50 vs. the graph I believe is a 1.98 C3+MW50.

The aircraft total drag coefficient should give us an indication of what power output the different graphs represent at sea level.  Total drag coefficient should be the same (aircraft hasn't changed).

Fixed Values for Calc:
Wing Area: 173 ft^2
Prop Efficiencey: .81
Air Density: .0023 slug/ft^3 (sea level air density)

Here are the variables:
1.8 ata B4+MW50 : 1850 hp, 370 mph
1.98 ata C3+MW50: 2000 hp, 379 mph

If the 1st graph isn't 2000 hp then we should see a difference in total drag coefficient.  Here are the results:


hp pe thp vmax D (lbs) CD
1850 0.81 1498.5 370 1518.7 0.0259
2000 0.81 1620.0 379 1602.9 0.0260


CD for both aircraft is at .026 which tells me that the first graph is an aircraft at 2000hp.

If it was less (say 1800 hp) CD=.023.

Tango, XO
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« Last Edit: March 04, 2007, 06:59:20 PM by dtango »
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Offline Benny Moore

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« Reply #162 on: March 04, 2007, 10:20:20 PM »
And that's the Me-109K in Aces High II?  This is so confusing.  I wish Hitech would come and explain just what kind of K we have.

Offline Knegel

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« Reply #163 on: March 05, 2007, 12:24:44 AM »
Quote
Originally posted by dtango

CD for both aircraft is at .026 which tells me that the first graph is an aircraft at 2000hp.

If it was less (say 1800 hp) CD=.023.

Tango, XO
412th FS Braunco Mustangs



Hi,

Thats my point, the rated altitude with MW50 is good above that of the DB605DC at 2000PS and the testers talk about a "Leistungsmaschine I" where they did clean the surface and did gain 12km/h as well.

Already the 109V24 got tested with a CD of 0.24-0.3 depending to the surface. This plane dont had closed wiheelcover , retakeable tailwheel and it did miss the round wingtips.

Greetings,

Knegel
« Last Edit: March 05, 2007, 01:23:40 AM by Knegel »