Author Topic: Bf 109F-4 performance research page (Read 3950 times)

GScholz · « **Reply #45 on:** February 09, 2005, 05:53:16 PM »

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Originally posted by Angus
Him?

Woot?

Bug is a girl?

Urchin · « **Reply #46 on:** February 09, 2005, 08:10:03 PM »

even if it is "undermodelled", the AH speed is still within 3.5% of that test.. which I'd say is a fair range in performance.. I'd imagine not *every* 109 topped out at 670 km/h.

BUG_EAF322 · « **Reply #47 on:** February 09, 2005, 08:46:10 PM »

U guys never run fast enough with ur leather suits.

Gawd i hear that village people song again

BUG runs away

Wmaker · « **Reply #48 on:** February 10, 2005, 04:22:47 AM »

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Originally posted by Urchin
even if it is "undermodelled", the AH speed is still within 3.5% of that test.. which I'd say is a fair range in performance.. I'd imagine not *every* 109 topped out at 670 km/h.

Like I said, personally, I haven't even seen a german flight test document that shows a result of over 670km/h in which Wotan referred to.

Pyro has said that with AH2 it is a lot easier to get the FM to hit the right numbers. The discussion about KI-84's top speed on the deck and how it got tweaked is a good example of that. Allready in AH the Dora hit the deck top speed within 1 mile compared to a flight test of a D-9 which used B4 fuel and MW-50 injection.

The fact that not every 109 topped out at 670km/h has nothing to do on how the planes are modelled in AH2 until AH2:ToD is here.

Naudet · « **Reply #49 on:** February 10, 2005, 05:30:21 AM »

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Like I said, personally, I haven't even seen a german flight test document that shows a result of over 670km/h in which Wotan referred to.

For the BF109F4 you can find the documents on the Webpage Wotan mentioned at the start of the thread. They are for different BF109Fs not a single "special" plane.

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Allready in AH the Dora hit the deck top speed within 1 mile compared to a flight test of a D-9 which used B4 fuel and MW-50 injection.

This is wrong, simply because so far it seems that not a single flight test for a D9 using MW50 exists.
The 1st D9 that was modified to carry out flight test with the MW50 system crashed before any tests could be conducted and after that the evaluation and function of the MW50 system for the D9 series continued on the ground.
And as far as i know neither the USAAF nor the RAE did any performance measurements with a captured D9 using MW50 that survived up to this day.

In D. Hermann's Book "FW 190 Long Nose" there is an account of Lt. Ossenkop who stated that at tree top level he achieved 605km/h using MW50.

Known flight tests for FW190D9s with JUMO213A are those for Wk.-Nr. 002 & 006 at Rechlin and Wk.-Nr. 043 at DB.
Additionally there were some performance measurements with the FW190D prototypes, namely the V20 & V58 if i remember correctly.
And some of the very early production planes Wk.-Nr. 003 & 004 were also flown in at Rechlin.
But all those test were done with a max powersetting of 3250rpm@1,5ata.
None of the planes flown at Rechlin had the MW50 system installed nor were they equipped with the "Ladedrucksteigerungsrüstsatz für erhöhte Notleistung".

Wmaker · « **Reply #50 on:** February 10, 2005, 07:58:36 AM »

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Originally posted by Naudet
For the BF109F4 you can find the documents on the Webpage Wotan mentioned at the start of the thread. They are for different BF109Fs not a single "special" plane.

Yep, I know. I just meant that I haven't seen one for G-2.

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Originally posted by Naudet
This is wrong, simply because so far it seems that not a single flight test for a D9 using MW50 exists.

I based my comment on this page:

http://jagdhund.homestead.com/files/DoraData/horizontalgeschwindigkeiten.htm

Of course the data in the chart can be calculated data. Even so, the fourth column matches the speed you stated within 1km/h. When I tested Doras speed on the deck in AH1 the speed was 376mph. Therefore I said "within 1mph". So what is wrong here?

Wotan · « **Reply #51 on:** February 10, 2005, 08:01:24 AM »

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Originally posted by Urchin
even if it is "undermodelled", the AH speed is still within 3.5% of that test.. which I'd say is a fair range in performance.. I'd imagine not *every* 109 topped out at 670 km/h.

The 109F-4 in AH2 only hits 394 mph on wep (7 min limit).

Even if you don't except 660-670 km/h and are happy with 394 mph (635 km/h) then that speed would better match 1.30 ata (AH military power or unlimited).

Get rid of the emergency power setting for the F-4 all together and match 1.30 ata with 635km/h. Emergency power would be limited to 3 to 5 min any way.

My point is more about speed at AH military power which is:

At 1.30 ata / 2500 rpm the AH2 F4 only does 382 mph (614 km./h)

Same with the G-2 emergency power (1.42 ata) speed in AH better matches the 1.30 ata climb and combat setting.

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Allready in AH the Dora hit the deck top speed within 1 mile compared to a flight test of a D-9 which used B4 fuel and MW-50 injection.

What flight test? Do you have one that shows the D9 speed/power settings with B4 and mw50?

EDIT, I see your reference know. I was posting at the time you did. I am sure Naudet will have a reply to that.

In AH the F-4 contemporary is the Spit Vb but the Vb runs at 16lbs boost (cleared for that Aug '42) If we are to believe the data in the link above the F-4 was cleared for 1.42 ata in Feb '42...

Wmaker · « **Reply #52 on:** February 10, 2005, 08:13:25 AM »

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Originally posted by Wotan
The 109F-4 in AH2 only hits 394 mph on wep (7 min limit).

Even if you don't except 660-670 km/h and are happy with 394 mph (635 km/h) then that speed would better match 1.30 ata (AH military power or unlimited).

Get rid of the emergency power setting for the F-4 all together and match 1.30 ata with 635km/h. Emergency power would be limited to 3 to 5 min any way.

I more or less agree here. Like you mentioned Spit V has 16lbs boost currently. So to even these too planes up for events I would reduce Spit's boost back to 12lbs as well as match the 109F-4s speed to 635km/h at 1.3ata and remove the WEP.

Naudet · « **Reply #53 on:** February 10, 2005, 08:23:02 AM »

Wmaker, i know the document very well on which Byran based his website, the numbers and curves from that document are calculated.

So it is right, AH's D9 matches the calculated data very well but not flight test data.
It is also conform with the statement of Lt. Ossenkop.

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So what is wrong here?

To use the term "flight test" is misleading here, as to my knowledge there simply doesnt exist any flight test for a D9 with MW50.
And to differentiate between calculated and flight data is very important.

Wmaker · « **Reply #54 on:** February 10, 2005, 08:52:39 AM »

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Originally posted by Naudet
To use the term "flight test" is misleading here, as to my knowledge there simply doesnt exist any flight test for a D9 with MW50.
And to differentiate between calculated and flight data is very important.

You are very much right that it was misleading. For that I'm sorry because I assumed it was from a flight test.

I do agree that it is important to make a difference between calculated data and numbers that are actually flown.

But the fact that the data is calculated doesn't have to mean that it's too inaccurate to be used. Like your example showed, when the plane was flown in unit it reached the speed very accurately. One would naturally assume that calculated data is usually too optimistic (and in many cases it has been) but there are also examples like VL Pyörremyrsky which was actually few km/h faster than the calculated data suggested.

The main point what I was trying make when I made the comment about the Dora was that HTC has proved that it can model the top speeds of these planes very accurately and that pyro has said that it can be done easier/more accurately in AH2 than in AH1. So if the speed is off it can be corrected if sufficient data is provided.

GScholz · « **Reply #55 on:** February 10, 2005, 09:23:54 AM »

Remove a 3-5 min WEP? Why?

The Frank got a 1 minute WEP, and so does the 109E-4 IIRC. Fix the numbers if necessary, but there is no reason to remove WEP if the plane had it. No matter how short it was.

You guys are like "let's correct this inaccuracy here, but compensate with a new one over there". Idiocy.

Do it right or don't do anything at all.

Wmaker · « **Reply #56 on:** February 10, 2005, 09:58:21 AM »

1.42 power setting IS the WEP.

If it wasn't cleared until Feb -42 and we want to get F-4 vs Spit adversaries which represent the time frame before that date, then yes we do want to remove a power setting which wasn't in use at that time.

*edited for grammar/spelling, no idea what is wrong with my english today...*

Wotan · « **Reply #57 on:** February 10, 2005, 10:04:03 AM »

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Remove a 3-5 min WEP? Why?

Its not entirely clear that 1.42 ata was cleared in FEB '42 (at least according to Butch) even if it is 5 min it wouldn't be that important if the 109F-4 could hit 394 (wep now) at mil power (unlimted).

You end up with a 109F-4 @ 1.30 ata / 2500 rpm hitting 635km/H @ 20k.

as opposed to:

1.30 ata / 2500 rpm the AH2 F4 hitting 614km/h @ 20k.

That's still slower then what the linked webpage shows:

1.30 ata / 2500 rpm 648km/h @ 20k or so...

I doubt anything will be done but to me the more significant issue is max speed at mil.

GScholz · « **Reply #58 on:** February 10, 2005, 10:15:26 AM »

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Originally posted by Wmaker

1.42 power setting IS the WEP.

If it wasn't cleared until Feb -42 and we want to get F-4 vs Spit adversaries which represent the time frame before that date, then yes we do want to remove a power setting which wasn't in use at that time.

*edited for grammar/spelling, no idea what is wrong with my english today...*

I Guarantee you that it had a WEP back then too. I have yet to see a LW plane without a take-off and emergency setting above max continuous power.

I you want an early F-4 then why not model an early and a late version. We do have the F4F and the FM2.

Wmaker · « **Reply #59 on:** February 10, 2005, 10:47:09 AM »

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Originally posted by GScholz
I Guarantee you that it had a WEP back then too. I have yet to see a LW plane without a take-off and emergency setting above max continuous power.

For example in finnish 109s the use of the WEP (1.42ata setting)was prevented at least in two different ways. One was wire to prevent the throttle quardant's movement and the other was this bolt which was fastened on a bent metal plate which attached in the throttle quardant.

Before the power settings were cleared for use LW used same kind of methods to prevent the pilots from over boosting the engine.

So, at a point in time with certain engines and certain planes there were no WEP. Sure you can find take off and emergency settings listed in books but that doesn't mean they were always available because of engine problems.

When I moved the throttle I could bent it sightly and move it past the bolt to full throttle. And of course wire can be broken. So there were ways to go past these but if the engines weren't able to handle these settings the results weren't pleasant.

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Originally posted by GScholz
I you want an early F-4 then why not model an early and a late version. We do have the F4F and the FM2.

I most definately would like to see so called early an late sub-variants for many planes we have in AH. IMO that would be the best way to handle this problem of differing boost pressures at different times during the war. Would be great for events and wouldn't require any new art work either. But until HTC makes a decision to implement variants like these I like the primary adversaries' performances to match.