109's kill ratio (all variants from B to K)

[GODO]

Originally posted by F4UDOA
An aircraft with higher drag will take longer to accelerate than one with lower drag even with higher HP many times.

It fully depends on initial and final speeds to measure that acceleration. More than problably, P51D would be massively outaccelerated from 150 to 300 mph by a 109K, and the opposite for higher speeds.

[F4UDOA]

First, do you have any data on the high alt performance of the P-51D using 150 octane fuel?

Second, since 150 octane fuel does not by itself increase HP did they replace the supercharger or merely increase boost pressure where the original blower could, i.e. at lower altitudes?
?I have what I posted, I do not have high alt 150 octane for those A/C. I do have a climb chart somehwere I am trying to flind that shows the P-51D climb rate at 4,000FPM+. Higher octane fuel does lower the critical altitude but that would olny match the loawer critical alt of the 109G10 which is also using C3 and MW50

Thirdly, when did the P-51's start using 150 octane fuel for most if not all operational units (as opposed to just a few specialized ones)?
Many of the units, not all. This was not just for V-1 chasers. It was deployed with the Navy as well for A/C that could use it. Not sure if the Navy used it during the war but it became common if not standard in some theaters of operation.

Fourthly, You say that combat weight for the P-51D was less than 9000 lbs. Does the P-51D have enough fuel to fight and then return to England from Berlin if it is weighing less than 9000 lbs?
I would say absolutely yes and I don't even know the distance between Berlin and England. I have the fuel cart for the P-51D. It could cruise at 400MPH at 30K for 3 hours plus on internal fuel only at 80GPH.  Remember the Mustang carried drop tanks for the ride in so fuel level would have been optional for the ride home.

Fifthly, you state that the 109 was "locked in concrete" above 400 mph, what documentation can you provide that support this?
Yes, JG26 War Diaries Georg Ganth flying a 109K-4 could not center his stick and it took both hands to roll back from being inverted at 500KPH IAS. BTW they did not like the K-4 they preffered the G10.

Sixthly, your acceleration theories do not match with (what I preserve as) reality. Drag is not the most important factor in accelerating at low speeds so if the 109 is faster, lighter and have more HP it MUST accelerate faster than the P-51D at low speeds. What documentation can you provide that refutes this logic? This is strictly thrust vrs drag. How much thrust is required to overcome X amount of drag. If the P-47C can accelerate as well as a P-38F then a Mustang can do at least as well as a 109. I can't do the math right now but I will shortly. BTW at sea level the Mustang is at least as fast with less HP required. The Mustang is designed for low cruise drag thats why it accelerates through those speeds ranges so well.

Seventhly, do you have any quotes from 109G10 and/or 109K4 pilots that say they felt the P-51D was superiorYes there is one in this thread I believe

[GScholz]

What was the drag coefficient of the 109K4 and the P-51D (operational, not test dragster)?

[GScholz]

Originally posted by F4UDOA
I have what I posted, I do not have high alt 150 octane for those A/C. I do have a climb chart somehwere I am trying to flind that shows the P-51D climb rate at 4,000FPM+. Higher octane fuel does lower the critical altitude but that would olny match the loawer critical alt of the 109G10 which is also using C3 and MW50

So the 109 would actually gain performance over the P-51 at higher alts since the 150 octane boost would lower the critical altitude of the P-51D?

Originally posted by F4UDOA
I would say absolutely yes and I don't even know the distance between Berlin and England. I have the fuel cart for the P-51D. It could cruise at 400MPH at 30K for 3 hours plus on internal fuel only at 80GPH.  Remember the Mustang carried drop tanks for the ride in so fuel level would have been optional for the ride home.

A commercial flight from London to Berlin takes about two hours flight time. At 9000lbs the P-51D would have only 67 gallons left of its internal fuel. Your numbers don't match up.

Originally posted by F4UDOA
Yes, JG26 War Diaries Georg Ganth flying a 109K-4 could not center his stick and it took both hands to roll back from being inverted at 500KPH IAS. BTW they did not like the K-4 they preffered the G10.

So the control weren't "set in concrete", he just needed both hands. You yourself discounted anectodal evidence earlier. Do you have anything except anecdotal evidence to support this?

Originally posted by F4UDOA
This is strictly thrust vrs drag. How much thrust is required to overcome X amount of drag. If the P-47C can accelerate as well as a P-38F then a Mustang can do at least as well as a 109. I can't do the math right now but I will shortly. BTW at sea level the Mustang is at least as fast with less HP required. The Mustang is designed for low cruise drag thats why it accelerates through those speeds ranges so well.

No, it how much thrust is needed to move X amount of mass. Just like with cars, rockets, airplanes, bullets, volcano lava and every other object that is accelerated. Drag only becomes a factor as speed increase.

Originally posted by F4UDOA
Yes there is one in this thread I believe

I can't find it, but then again I might be going blind for all I know.

[Nashwan]

First, do you have any data on the high alt performance of the P-51D using 150 octane fuel?

High alt performance, at critical altitude and above, would be the same.

Second, since 150 octane fuel does not by itself increase HP did they replace the supercharger or merely increase boost pressure where the original blower could, i.e. at lower altitudes?

They allowed higher pressure at lower altitudes. Because of the relatively high critical alt on the engine, that means a power increase up to 20,000ft or so.

Thirdly, when did the P-51's start using 150 octane fuel for most if not all operational units (as opposed to just a few specialized ones)?

The 8th AF switched to 150 octane in early summer 44, for the vast majority, if not all, their Mustangs. The RAF had already switched most home based fighters over. 8th AF fighters used approx 20,000 tons of 150 octane per month.

So the 109 would actually gain performance over the P-51 at higher alts since the 150 octane boost would lower the critical altitude of the P-51D?

No, the critical altitude was lowered for the higher power setting. For example, if the V-1650-7 could maintain 67 in HG up to 20,000ft, the critical altitude would be 20,000ft. If it could maintain 81 in HG up to 14,000ft, then critical altitude at 81 in HG would be 14,000ft. Power would then decline until 20,000ft, where it would match the figure at 67 in HG. Between 14,000ft and 20,000ft, although the power would be declining, it would still be higher than at 67 in HG.

[GScholz]

I see. Thanks.

So in the end what I said initially was correct. 150 octane fuel will allow the P-51D to match the 109K4 in low alt performance (edit: speed only), but as alt increases the 109K4 would gain superiority as it was over the 100/130 octane P-51D's. Perhaps AH should get a late war P-51D using 150 octane fuel as a perk Pony ... and the 109K4 of course!

[GScholz]

Hmmm ... one issue just popped up in my mind. If they increased boost pressure, they increased fuel consumption (unlike MW50), which increases both power and heat buildup. Unless there was some cooling agent or modified cooling system the engine would overheat considerably faster than under normal WEP. Wouldn't it? If so, does anyone know how long these Ponies could run at +25 boost?

[Nashwan]

According to the manual, 25lbs boost was limited to 5 mins, same as 18 lbs boost (Note the US didn't allow 25 lbs at all, something like 76 " HG, 21 or 22 lbs boost iirc).

The Spit IX had the same limitations, 5 mins at 18 lbs and 5 mins at 25lbs. Neil Sterling posted the cooling trials of the Spit IX at 25lbs. Under temperate summer conditions, 10 mins cruise at max normal power, followed by a 5 mins climb at 25 lbs, all with radiators shut, took temp just up to max allowable, but not over.

10 mins cruise and 5 mins at 25 lbs, all level flight, radiators shut, kept temperate well under max allowable, even under tropical summer conditions.

[GScholz]

Originally posted by Nashwan
According to the manual, 25lbs boost was limited to 5 mins, same as 18 lbs boost (Note the US didn't allow 25 lbs at all, something like 76 " HG, 21 or 22 lbs boost iirc).

And what power did this boost yield? 2000hp? I find it strange that the boost time is the same. Either they improved cooling somehow or the 18lbs boost was unnecessarily restricted and could have been used longer?

Originally posted by Nashwan
The Spit IX had the same limitations, 5 mins at 18 lbs and 5 mins at 25lbs. Neil Sterling posted the cooling trials of the Spit IX at 25lbs. Under temperate summer conditions, 10 mins cruise at max normal power, followed by a 5 mins climb at 25 lbs, all with radiators shut, took temp just up to max allowable, but not over.

By 10 minute cruise you mean the engine temp was nominal or below nominal? Was this procedure limited to 10 min or could the Spit cruise for longer at mil power and still use the boost?

Originally posted by Nashwan
10 mins cruise and 5 mins at 25 lbs, all level flight, radiators shut, kept temperate well under max allowable, even under tropical summer conditions.

I find this strange, couldn't the boost be used indefinitely then? Or did the piston heads overheat? If so why didn't they overheat faster at 25lbs than 18lbs, as one would expect? Did they strengthen the Merlin (new model)?

[HoHun]

Hi Nomak,

>I do of course respect your opinion on the matter.  

>I strongly disagree........

Just note that your statement concerning the general superiority of the Mustang is an opinion, while my statement concerning the superior speed and climb performance of the Me 109K-4 over the P-51D at low to medium altitude is a fact.

Regards,

Henning (HoHun)

[Neil Stirling1]

I asked Butch about those 109K performance figures posted above by Isegrim and it would seem that they are calculated.  Has any one got actual flight test performance data for the 109K?

Neil.

[Nashwan]

And what power did this boost yield? 2000hp? I find it strange that the boost time is the same. Either they improved cooling somehow or the 18lbs boost was unnecessarily restricted and could have been used longer?

It often was used for longer. There's lots of annecdotal evidence that pilots ran wep for longer. Early Hurricanes and Spits during the BoB were limited to 12 lbs boost, for 5 mins only. I saw one pilot account of using 12 lbs for takeoff, and leaving it at that throughout the flight (deliberately)

By 10 minute cruise you mean the engine temp was nominal or below nominal? Was this procedure limited to 10 min or could the Spit cruise for longer at mil power and still use the boost?

From the wording of the test, as well as it's purpose (to determine if cooling was adequate at 25lbs boost) the 10 mins at maximum cruise was used to warm up enough to get an accurate figure from the combat power (25lbs) runs.

Don't forget the plane would have been warmed up on the ground first, and then climbed to test altitudes.

The test is a cooling report by the A&AEE to determine if Spit cooling is adequate for the new 25lbs rating. I should think they tried to replicate real life conditions, ie long cruise, period of combat etc.

Don't forget, even the cruise portion of the test was done with rad flaps shut, whereas in normal conditions the flaps would be open.

I find this strange, couldn't the boost be used indefinitely then? Or did the piston heads overheat?

I don't know what the limiting factors were. I suspect engine life was one of the main ones. I know that with extended running at 18 lbs or 25lbs, the exhaust stubs would burn out.

If so why didn't they overheat faster at 25lbs than 18lbs, as one would expect?

I should think they did, but not by that much. The Merlin used the fuel for charge cooling, and the greater fuel flow at 25lbs would have helped reduce temperate. But even then, I would expect an engine running at 25 lbs to break sooner than an engine at 18lbs.

Did they strengthen the Merlin (new model)?

No, same Merlin. The early Merlin 61 engines couldn't take 25 lbs, but the Merlin 63, 66 and 70, all used in the Spit IX from late 42/ early 43 onwards could take 25 lbs. I'm not 100% sure about the V-1650-3, though I think it could run at 25lbs, but the V-1650-7 certainly could.

[GScholz]

I find this very interesting. I know the late 109's were superior in combat, but I've always felt that the Ponies in AH were too easy kills. Sure pilot quality and overwhelming odds were the primary factors in late 1944 and 1945, but still ... I think AH needs a late 1944 P-51D with 150 octane and a late war Spit IX, but the problem from HTC's point of view might be getting accurate data. Both would probably need to perked though. Same with 109K4 if we get it.

Woah! Look at me ... I turned out to be an alliedweeb. Who would have guessed.


Edit: Still, F4UDOA is way off with his über performance figures. You can't strip down the Pony like that in operational service. If you removed the bomb racks the Pony can't carry the DT's and that aerial bracket was there for a reason too. And btw. most Ponies didn't have paint (except on the nose and insignias).

Woups ... relapse to Luftwobble status ... oh well

[VO101_Isegrim]

Originally posted by Nashwan
Just to make it clear, Isegrim's charts show the 109K4 at 1.98 ata, which wasn't authorised until March 45, and 1.8 ata, which wasn't authorised until Feb 45.
[/qoute]

Just to make clear, Nashwan often makes up ridiculus things, like +25lbs being standard on Spit XIVs, or nonexistent "ghost" Spitfire XIV squadrons which are supposed to serve in India during WW2, or funny theories for the Murmansk convoys. This case is of no exception. His imagination knows no borders when it comes to making up false stories.

1.8ata was authorized from the very beginning, and 1.98ata was cleared already in 3rd (!!) edition of the DB 605DC manual, dated November 1944.

The only reason he invents these lies is because the true performance of the Bf 109 is red carpet to him (they so much outclass his precious Spit), and he needs to degrade this performance, if at nowhere else, in his wild fantasies.

His figures for the P-51 are with 100/130 fuel, not the 100/150 they switched to in summer 44. 100/150 allowed higher manifold pressure, up to 81 in HG in RAF service, a bit less in the 8th AF. That gave up to 2000 hp in the Mustang.[/qoute]

Just to make clear, Nashwan has again no idea of what he is talking about. First, not all Mustangs switched to 150 grade. Second, he "forgots" to mention that the 8th AAF used only 71" Hg with their Mustangs, instead of 67", when running on 150 octane. The reason for that was the enourmous increase in maintaince work due to using 150 grade, and frequent use of spark plugs. The power increase was rather modest this way. +14" is supposed to give +250 HP, so +4 is unlikely to give more than 70-80 bonus HP.

In flight tests, the actually measured max. SL speed of the P-51 D was only 359 mph at +67 Hg boost. As it is shown, my figures are significantly higher than that, so it`s for 150 grade fuel.

Also, not even +81 HP gave 2000 HP in the Mustang, only 1940, and only up to a mere 500 ft, then power fell of due to insufficent superchargin.

[VO101_Isegrim]

Originally posted by Neil Stirling1
I asked Butch about those 109K performance figures posted above by Isegrim and it would seem that they are calculated.  Has any one got actual flight test performance data for the 109K?

Neil.

The figures are NOT calculated for the 109 K - they are based n real life test, butch himself told you that very clearly. You know it very well. Why trying to make something different of that ? Because somehow you managed to convince yourself that no single real life test exist for German planes, therefore you can ignore their performance on the basis that "oh, every spec is calculated, never reached".

It seems you always find it very hard to accept the real life performance of German planes. Why is that Neil ? Preconception ?

Some of the figures on the graph are calculated - those performance figures for the new type VDM 12 199 "Dunnblatt" propellor, not for the "normal" figures I gave for the VDM 12 159 propellor. The former would increase maximum speed by 10-15 kph at the high altitude.

Again, the figures posted are from REAL LIFE tests. And Butch told you that.

You know Neil, the performance you and Nashwan producing here is a rather miserable one. You are hiding your heads in the sand.