P-47: We could easily out-turn the Jerry

[gwshaw]

Originally posted by Kurfürst
In 1944 testing of the P-47N prototype a P-47D-35 (IIRC) clocked in at 450 mph @ approx 30,000 ft. Which fits right in line with calculated figures for a D-25+ w/o wing pylons.

The P-47M/N was indeed very fast, very late, and very rare. I though we are talking about the D version, which was in question. Certainly the N was by no means represenative of D performance.

I am NOT referring to the N prototype that did hit 450 mph with the "C" series engine. There was a D-35 that flew mock combat and comparisons to the N prototype. It hit 450 mph with the standard -63 "A" series R-2800.

snip

So, with wing pylons attached the -3 engined was definitely a bit faster above 8km then the K-4.

P-51B/-3 w. pylons : 700kph 8230m
K-4 : 705 kph at 8000m
So certainly not.

2 mph slower than the peak of the K-4, but at 800+ ft greater alttitude. IE the K-4 would be falling off about 1-2 mph in that difference. I'll restate, there wouldn't be any significant difference between them at 27,000 ft and the Pony's speed should drop off a bit slower with altitude.

And without pylons both -3 and -7 engined models could manage 450 mph or so, about the same peak speed as the K-4, but about 10 kft higher. Leaving aside the question of whether or not the K-4 ever had the fuel to make those figures.

Point is they never flown without pylons in USAAF service. Standard fitting, required for long range sorties.

Correct, but my point is that a CLEAN P-51 is faster peak than a CLEAN K-4, even the -7 models. Although the K-4 certainly has a pronounced speed edge in the 18-22,000 ft range over either engined Pony running on  100/130 and limited to 67 in Hg.

And a standard B w/-3 engine (circa late '43) is just as fast as a K-4 (circa late '44/early '45) above that 8 km altitude.

We have already concluded the -3 engines made the sleeker P-51B as good as the K-4, not much difference to speak of.
The V-1650-7 had poorer power output than the -3 at altitude, which would make it slower, plus if we speak of the most common config (draggier P-51D w. V-1650-7, wingracks), it is definieately at speed disadvantage to the K-4 at altitude.

I agree completely, but the B is about a year earlier than the K-4. The USAAF made a conscious decision to reduce high altitude performance in order to increase carrying capacity and medium altitude performance. The K-4 would be slightly faster above 8 km than a stock D running at 67 in Hg, but faster in the 22-25 kft range than a -3 engined Pony. Again there wouldn't be much to pick and choose between a stock D and a K-4 in that altitude range, both would be in the high 430/low 440 mph range. The D probably a bit better at the high end of the range, the K a bit better at the low end. With the K starting to regain some edge above that since it had a couple thousand foot edge in rated altitude.

What graphs Neil Stirling posted show the D version to achieve some 663 kph at 10000m - that`s 20 km/h slower than the K-4 at 681 kph at the same altitude, and about as fast as a G-10 or /AS types. Two staged versions of the DB 605 D would rule out the even playing fields for the comparisons, though.

And the -9/-11 coming out would have greatly improved performance at high and medium altitudes over the -7.

I don`t get your fuel comment. Without fuel either the P-51 was some 700 km/h slower than the 109K and vica versa. Otherwise the type of fuel or the use of MW did not effect the altitude performance above 7000m or so at all, just as 150 grade fuel couldn`t.

I was referring to this earlier statement of yours, "All the rest were slower, some even as fast, particularly the P-47D and P-51D, neither of which can even hit the top speed of the K-4"

I assumed it was the 452 mph / 730 km/h @ 6 km / 18,700 ft figure for the K-4's peak speed you were alluding to. IIRC that was with C3+MW50, B4+MW50 peaking somewhere in the 435-440 mph range at a bit higher altitude. So with B4+MW50 the peak speed wasn't any higher than a pylon equipped B/C/D could manage. I might be mistaken on that since I don't have my references handy, so that 452/730 figure may be with B4+MW50, but I don't believe so.

If I have some time I'll work up some 72 in Hg, 75 in Hg and 80 in Hg figures for the -3 and -7, then plug them into my P-51B and P-51D models and see what comes out.

My engine and plane models are both in a bit of disarray right now, but I'll see what I can come up with. I'm still working on a brand new engine model, and improving the exhaust thrust part of my plane model.

Greg Shaw

[MiloMorai]

Originally posted by Kurfürst
Why would me or anybody post actual data for you, hmm?

Because you are the one one making claims that you can't back up with any proof.
It is not just me you have prove to what your claim is fact. Therefore, NO ONE  will believe your bogus claims.

Conclusion, you don't have any data (actaul flight tests, not factory calculations) on the K-4 and you are afraid all will see the real truth on the K-4s performance.  

[Kurfürst]

Originally posted by gwshaw
I am NOT referring to the N prototype that did hit 450 mph with the "C" series engine. There was a D-35 that flew mock combat and comparisons to the N prototype. It hit 450 mph with the standard -63 "A" series R-2800.

Probably so, but I have never seen any D series being that fast - I see 690 kph for them all the time. But, I dont know all those P-47 variants in details, but if the s/c or prop wasnt improved, there is little chance the altitude performance would get better - perhaps the plane you refer to didn`t have the racks, unlike operational ones.



Point is they never flown without pylons in USAAF service. Standard fitting, required for long range sorties.

Correct, but my point is that a CLEAN P-51 is faster peak than a CLEAN K-4, even the -7 models. Although the K-4 certainly has a pronounced speed edge in the 18-22,000 ft range over either engined Pony running on  100/130 and limited to 67 in Hg.


And a standard B w/-3 engine (circa late '43) is just as fast as a K-4 (circa late '44/early '45) above that 8 km altitude.

Yep. Though I feel the B Mustang was more like early 1944, they flew only a handful of sorties in december `43 w. the 8th AF.  Speaking of intro dates, I`d willing to bet a 109G-1 from mid-42 is at least as fast as K-4 at altitude with GM-1, it had even more power with that (somewhere around 1000 HP at 10km), very easily above 700 kph in any case. F-4/Z would be also in their heels.   These were specialiyed altitude fighters, though.



I agree completely, but the B is about a year earlier than the K-4. The USAAF made a conscious decision to reduce high altitude performance in order to increase carrying capacity and medium altitude performance. The K-4 would be slightly faster above 8 km than a stock D running at 67 in Hg, but faster in the 22-25 kft range than a -3 engined Pony. Again there wouldn't be much to pick and choose between a stock D and a K-4 in that altitude range, both would be in the high 430/low 440 mph range. The D probably a bit better at the high end of the range, the K a bit better at the low end. With the K starting to regain some edge above that since it had a couple thousand foot edge in rated altitude.

Pretty much agree!


And the -9/-11 coming out would have greatly improved performance at high and medium altitudes over the -7.

If you mean the p-51h, that thing was definetely a monster speedy plane, no doubt. Do you have some graphs on those engines?




I assumed it was the 452 mph / 730 km/h @ 6 km / 18,700 ft figure for the K-4's peak speed you were alluding to. IIRC that was with C3+MW50, B4+MW50 peaking somewhere in the 435-440 mph range at a bit higher altitude. So with B4+MW50 the peak speed wasn't any higher than a pylon equipped B/C/D could manage. I might be mistaken on that since I don't have my references handy, so that 452/730 figure may be with B4+MW50, but I don't believe so.

The 452mph figure is actually coming from the same doc I am using, for a 4bladed prop they toyed with /both fuels/, w. reference to the perf w 3bladed prop. It made it some 10kph faster at altitude, but was not serialized.

Top speed w the normal prop was 712-15 kph, regardless of fuel, but with c3/2000ps it was reached at a wider alt. range, ie. see below :

http://www.onpoi.net/ah/pics/users/715_1104924968_spd_109gkvsixvs190ad.jpg

You can compare your p51 data points to this w. the 109K.

[Angus]

You'd be surprized where a 1943 Spit VIII (long range) racks up in that speed chart.
Say alone at 25 boost.

[Crumpp]

You can compare your p51 data points to this w. the 109K.

You going to add the Dora using C3 and MW 50 to that graph.  It was in use weeks  before the 1.98ata 109K rating.  The 109K  was cleared for 1.98ata in the last two or three weeks of the war.  





It was substantially faster than the 109K at low altitudes.

Your graph shows the truth but not in the context of service date, leading to some seriously flawed conclusions.

All the best,

Crumpp

[MiloMorai]

There was a comment made about certain P-47 models being rare. So was the K-4 @ 1.98ata.

Olivier Lefebvre, noted authority on the BF 109, has stated:

    The DB605DM was cleared up to 1.75ata, the DB605DB pushed the limit up to 1.8ata, both could be sustained with use of either B4+MW-50 (as mentionned in various documents, even if it was an afterthought in the DM case) or C3-MW-50. However the DB605DC max boost at 1.98ata could be achieved with use of C3+MW-50 only.

    As for the fuel supply, I own copies showing detailed stockpile status for February-April 1945... But yes the C3 was definitely scarce.

    As of March 1945 only a handful of 109 gruppen were using C3 for their mounts, one of the few being the II/JG11 which were responsible for testing the 605DB/DC over January-March 1945. According to a document dated late January 1945 coming from DB the 1.80 had just been cleared following serious troubles (pre-ignition) reported by the unit testing the 1.80 ata boost. It is also noted that following the clearance of the 1.8ata boost the 1.98ata operational tests could now begin but with concern about the sparkplugs thermal resistance IIRC. C3 was not used by 109 units until the 1.98ata boost was cleared, they relied on B4+MW-50 so that C3 could go to the 190 units. And even after the clearance only few gruppen got it because of shortages due not only to C3 production but also to C3 delivery to the units.

    AFAIK 1.98ata boost was cleared late February but it seems to have been slowly introduced into service, I suspect the adjustments needed on the engine and the change of sparkplugs type (supply problems ???) took longer than expected. From other documents I know that C3 and B4 had severe quality problems beginning in late 1944. While it was not much of a problem with low boost, it had some serious effect on higher boost, so it might also have slowed down the introduction of 1.98ata boost. At least DB documents underlined the need for cleaner fuels than those in use at that time. You can safely assume that by March 1945 1.98 ata boost was being introduced, unfortunately I do not have much details for April 1945, but I doubt it would have changed much, given the situation.

[MiloMorai]

Since homemade graphs, of questionable authenticiity and not backed up by factory flight test data graphs, are being presented some more by Mike Williams.

http://www.spitfireperformance.com/spit14v109.html

[Kurfürst]

Originally posted by Crumpp
You going to add the Dora using C3 and MW 50 to that graph.
 It was in use weeks  before the 1.98ata 109K rating.

[/B]

Never seen any evidence of any use of C-3 by D-9 units, perhaps you can show some. Also I don`t get why would the D-9 be any faster using 96 octane fuel than 87 octane fuel, if it`s running at the same 1.8ata boost.

The 109K  was cleared for 1.98ata in the last two or three weeks of the war.  

Also wrong, it was cleared in the last 5-6 months, and by March `45, at 100-150 K-4s were running at it already.


It was substantially faster than the 109K at low altitudes.

Your graph shows that not. At ca. 2000m altitude, the D9 w. C3 fuel achieves some 653 kph, same as the K-4.
Appearantly, your well known zeal the 190 was best in everything distorts your ability to read the facts from the charts.

I know the little graph will get some reactions from the usual crowd, even if it was posted only to help out greg w. K-4 performance.

[Kurfürst]

Appearantly butch somehow missed orders from the OKL, Lw.-Führüngstab, Nr. 937/45 gKdos.(op) 20.03.45.

This order, apart from ordering 95% of the existing 109 units to convert to the Bf 109 K-4 as soon as deliveries permit, also notes in relation of I./JG 27, III./JG 27, III./JG 53, IV./JG 53 to increase their maximum boost pressures to 1,98 ata manifold pressure.

II./JG 11 was already using it.

This means apprx. 150 aircraft that converted to 1.98ata, not counting previous units that may have done it before that order came out.

[Kurfürst]

Originally posted by Angus
You'd be surprized where a 1943 Spit VIII (long range) racks up in that speed chart.
Say alone at 25 boost.

I tell you, simply f. poorly.

[Kurfürst]

Originally posted by MiloMorai
Since homemade graphs, of questionable authenticiity and not backed up by factory flight test data graphs, are being presented some more by Mike Williams.

http://www.spitfireperformance.com/spit14v109.html

Indeed you are rigth, Mike as usual manipulated that chart heavily. He picked a 109K for climbs that was 200kg heavier, he shows a K-6 but lies and labeled it K-4, he shows the DB engine without MW 50 and so.

Poor Mike, if he would know what I am cooking for him right now.

[MiloMorai]

Originally posted by Kurfürst
Appearantly butch somehow missed orders from the OKL, Lw.-Führüngstab, Nr. 937/45 gKdos.(op) 20.03.45.

He did?  I think someone has reading problems.

" AFAIK 1.98ata boost was cleared late February but it seems to have been slowly introduced into service,"

And has trouble with numbers. Feburary (02) is the month before March (03) on the calender.

This order, apart from ordering 95% of the existing 109 units to convert to the Bf 109 K-4 as soon as deliveries permit, also notes in relation of I./JG 27, III./JG 27, III./JG 53, IV./JG 53 to increase their maximum boost pressures to 1,98 ata manifold pressure.

II./JG 11 was already using it.

This means apprx. 150 aircraft that converted to 1.98ata, not counting previous units that may have done it before that order came out.

Oh yes those miniscule deliveries. And, where did they get the fuel from? II./JG 11 had disappeared by April (04) 9 1945 for it does not appear on any OoB that I have seen.

A couple of weeks after the order came down,

I/JG 27   had 13 flight capable 109s
III/JG 27 had 15 flight capable 109s
III/JG 53 had 24 flight capable 109s
IV/JG 53 had 27 flight capable 109s

Also wrong, it was cleared in the last 5-6 months, and by March `45, at 100-150 K-4s were running at it already.

Another wishful thinking dream by Barbi.

Your problem is you have zilch credibility while Butch has tonnes of credibility because he does not manipulate for a biased agenda.

[Kurfürst]

Well the DB 605 DB/DC manual issued 1st December 1944 notes the 1.8 and 1.98ata boost being cleared, the 20th January doc butch himself posted says the boost was already issued to the troops, Galland himself and engines were set for it (' 'diese Leistungen direkt der Truppe angeboten wurden und die Motoren umgestellt werden'), but some further testing is required, then we have the direct order of OKL on the 20th March issuing orders to the mentioned units, save those that already switched to it in February as butch noted.

Overview of unit strenghts for the units that used 1,98ata.
As per 9th April 1945.

unit - 109s w unit
I./JG 27 - 29
III./JG 27 - 19
III./JG 53 - 40
IV./JG 53  - 54
Total : 142


Some zealots like Mike can go partisan and piss into the wind if they like, but there is overwhelming amount of evidence and makes their entire behaviour look like futile clown action.

[MiloMorai]

Originally posted by Kurfürst
Indeed you are rigth, Mike as usual manipulated that chart heavily. He picked a 109K for climbs that was 200kg heavier, he shows a K-6 but lies and labeled it K-4, he shows the DB engine without MW 50 and so.

Poor Mike, if he would know what I am cooking for him right now.

Your biased hatred has you not seeing clearly as there are 3 109K graphs with mit/with noted.

At least Mike put on his graph contemperary a/c unlike in yours which gives a false impression to further your UBER German agenda.

A K-6 was flight tested at Rechlin and some 3700 or so were to be built.

[Kurfürst]

Originally posted by MiloMorai
Your biased hatred has you not seeing clearly as there are 3 109K graphs with mit/with noted.

[/B]

No, my darling, what Mike Williams does is taking the DC graph which notes 'ohne MW', and then puts its data on his own chart, and claims it`s maximum performance on 1.8ata, when it`s not. Of course if he`d choose the right chart, he would have to show with much better performance both low and high.

Then he tooks the data for the slower K-6, but lists it as a K-4 on his own. Let`s not even mention the really lowly trick of putting the 109K with thin yellow line on white background, so that everyone will have difficulty seeing how badly the K-4 outpaced the SpitXIV - even compared to Mike`s own imaginative performance curve on +21 lbs.
Really classy from Mike, lowest performance on low boost and wrongly labeled, hardly visible curves for high boost.

The he gets data for a 3550 kg projected K-4 graphs from May 1944, 200 kg heavier than the normal K-4 - yeah, 'fair' representation of climb performance! And of course a little more tricks for Sondernotleistung, Mike`s chart says it 'experimental propellor'. The original doc says the serial and experimental prop produces the same climb performance, but nice trick to dismiss the numbers.



At least Mike put on his graph contemperary a/c unlike in yours which gives a false impression to further your UBER German agenda.

He doesn`t even do that, he doesn`t listen ASM equipped 109s at all, just two extreme ends - AS ones that are only fast at low altitude, and AM ones that are only fast at low altitude. Not the variant that was fast both low and high.

And as for contemperary a/c, I cannot imagine any more contemperary a/c to the G-14s, G-10, K-4s than IXLFs. Mike hides those like ugly sisters, even if there were 20 IXLFs for every XIVs that managed to show up in the skies once in a month.

Well he will get that summerized in an article soon enough. I told him to re-think it a bit before his manipulated articles will leave an long lasting impression in many regarding the credibility of his site, he choosed not to...