109 e4 performance

[bugmenot]

Originally Posted by Crumpp

Ok, we can ballpark the vicinity of the speeds we should be seeing at each of the settings by using the basic math relationships of power required to power available. Most of you won't know what I am talking about but it works.

For these ratings:

2) Startleistung 1175 PS in 0 m Höhe = 500kph
(zulässige Dauer 1 Min.)
bei 2500 U/Min.

3) Bodenleistung 1015 PS in 0 m Höhe = ~474kph
Kurzleistung (5 Min. Dauer)
bei 2400 U/Min.

Erhöhte Dauerleistung 950 PS in 0 m Höhe = ~465 kph
(zulässige Dauer 30 Min.)
bei 2300 U/Min.

Dauerleistung 860 PS in 0 m Höhe = ~449 kph
bei 2200 U/Min.

That is based on Mtt's contractual performance with the RLM and of course has a +/- 5% and assumes the radiator is in the same position as the 1 minute rating. This is a quick ballpark and it can be refined.

There's typo in the Baubeschreibung: M o t o r l e i s t u n g
http://kurfurst.org/Performance_test...chreibung.html

should be 1045 PS in 0 m Kurzleistung (5 Min. Dauer)
bei 2400 U/Min.

[Robo.]

Originally Posted by bugmenot

There's typo in the Baubeschreibung: M o t o r l e i s t u n g

I pointed out that typo already and it has been already corrected in the chart I am putting together, bugmenot.

[TomcatViP]

I don't know who put the variable s/c case frwd but the chart above posted by Bugmenot show precisely that there was none

One 1946's like hypothesis that can be thrown away

?
I dunno how you conclude from bugemots chart that there had been no variation in speed from one plane to another. Actually Kurfürst's chart clearly provides proof that there had been significant scattering in speed. Indeed this chart is highly interesting as one might be able to transpose the scattering in speed to that one for the Emils.

However it also prooves that the manufacturer's spec were likely spot on. So I now tend to think that there were 109E could indeed reach 500 kph or more. However it also shows that the real obtained mean value would probably be below the 500 kph because only three of the 13 managed to surpase the theoretical mean value of the spec.

[CaptainDoggles]

Originally Posted by 41Sqn_Stormcrow

?
I dunno how you conclude from bugemots chart that there had been no variation in speed from one plane to another. Actually Kurfürst's chart clearly provides proof that there had been significant scattering in speed. Indeed this chart is highly interesting as one might be able to transpose the scattering in speed to that one for the Emils.

However it also prooves that the manufacturer's spec were likely spot on. So I now tend to think that there were 109E could indeed reach 500 kph or more. However it also shows that the real obtained mean value would probably be below the 500 kph because only three of the 13 managed to surpase the theoretical mean value of the spec.

If you're familiar with statistics, you'll know that 13 aircraft of the 33000+ that were produced is not a representative sample.

The mean certainly could have been lower than 500, but it just as easily could have been higher. This is why I think it's silly to use anything other than this figure.

At least Microsoft was satisfied with testing only 13 aircraft. So why should we be less.

Oh, and I am very familiar with statistics. But I tend to adopt a pragmatic approach to problems. We do not have more than these 13 figures and we have to work with what we got. Anything else is just pure guessing around.

[CaptainDoggles]

Originally Posted by 41Sqn_Stormcrow

At least Microsoft was satisfied with testing only 13 aircraft. So why should we be less.

It's a matter of opinion I suppose.

Oh, and I am very familiar with statistics. But I tend to adopt a pragmatic approach to problems. We do not have more than these 13 figures and we have to work with what we got. Anything else is just pure guessing around.

I wasn't implying that you weren't familiar with statistics, please accept my apologies if you took it that way.

[Robo.]

Originally Posted by 41Sqn_Stormcrow

However it also prooves that the manufacturer's spec were likely spot on. So I now tend to think that there were 109E could indeed reach 500 kph or more. However it also shows that the real obtained mean value would probably be below the 500 kph because only three of the 13 managed to surpase the theoretical mean value of the spec.

That's highly possible, the question is (still) what engine, what ata, what RPM, what rad settings etc etc. If we talk about DB 601Aa at 1.45ata, 2500RPM and rad nearly closed, that's about right. If we get certain variability (say +- 3 percent), that would be fantastic as some machines would be able to get above the treshold as in real life perhaps.

I would really appreciate to get some opinions on numbers.

The chart with the 13 planes tested is with respect to the 109G so we cannot transpose the absolut numbers to the 109E. But it is a sound assumption to transpose the grade of scattering to the 109E imho. That is what should be kept from the chart.

My guess is also that the 109G figures and the configuration in which they were flown correspond to that set for the spec. Otherwise it would not make sense.

I also assume that the scattering between individual planes is the same as long as they fly at the same configuration whatever this configuration would be. So the scattering will not be influenced by radiator opening or ata as long as all planes use the same ratiator opening or ata.

EDIT: np, Doggles.

[Crumpp]

There's typo in the Baubeschreibung: M o t o r l e i s t u n g

Then the velocity will be ~490kph at that engine setting.