[REPORTED] K-4 level speed

[Pilum]

So as I understand it, what we should expect (from talking to Yo-Yo) is 580-585 (plausible to reach 590 even). This is what we should see.

 

OK, thanks for the info and that certainly sounds plausible. I get 587 km/h at sea level in my C++ simulations but I think I may be a bit on the optimistic side. :)

[NineLine]

OK, thanks for the info and that certainly sounds plausible. I get 587 km/h at sea level in my C++ simulations but I think I may be a bit on the optimistic side. :)

 

Well as you know conditions can make things vary slightly, such as Yo-Yo suggested coolant temps could cause things to change +/- 3kph. So its all close and within reason I think.

[Pilum]

Well as you know conditions can make things vary slightly, such as Yo-Yo suggested coolant temps could cause things to change +/- 3kph. So its all close and within reason I think.

 

Definitely. Also nice to see that things worked out well in the end and a good judgement call by the developers IMHO. :thumbup:

[Hummingbird]

I guess we're stuck with a Bf-109 G-10 then. Had a little hope in ED's propjobs for a while there, oh well..

[Hummingbird]

So as I understand it, what we should expect (from talking to Yo-Yo) is 580-585 (plausible to reach 590 even). This is what we should see.

 

The latest German graphs clearly state 595 km/h. Are they not good enough for Yo Yo?

 

605-610 km/h should be expected if the graph is not taking into account exhaust thrust, something actual flight tests confirm and Yo Yo himself even suggested.

 

Does Yo Yo honestly believe that wheel well doors, retractable tailwheel & 50 extra PS only adds an extra 12 km/h?

Edited February 16, 2016 by Hummingbird

[NineLine]

The latest German graphs clearly state 595 km/h. Are they not good enough for Yo Yo?

 

I guess we're stuck with a Bf-109 G-10 then. Had a little hope in ED's propjobs for a while there, oh well..

 

I am not sure I can get past the 'tude to even discuss this with you. I mean I have to go home and deal with a teenage girl, I have enough attitude in my life.

[Hummingbird]

I am not sure I can get past the 'tude to even discuss this with you. I mean I have to go home and deal with a teenage girl, I have enough attitude in my life.

 

No attitude, merely a question as I am honestly scratching my head regarding why he could ever reach the conclusion that 580 km/h is correct, esp. when no German document backs it up.

[NineLine]

No attitude, merely a question as I am honestly scratching my head regarding why he could ever reach the conclusion that 580 km/h is correct, esp. when no German document that I have seen backs it up.

 

Fixed that for you.

[Hummingbird]

Fixed that for you.

 

No Sith, there actually is none which back a 580 km/h top speed. Unless he has one newer than this:

 

 

[NineLine]

No Sith, there actually is none which back a 580 km/h top speed. Unless he has one newer than this:

 

 

There is more to researching the 109 than is found on the internet.

[Hummingbird]

There is more to researching the 109 than is found on the internet.

 

Ok, I give up.

[NineLine]

Ok, I give up.

 

Whew... finally.

[Hummingbird]

Whew... finally.

 

Well if Yo Yo has a chart newer than the one presented before that says the K-4 does 580-590 km/h at 1.8 ata then there's nothing to argue about really.

[NineLine]

Well if Yo Yo has a chart newer than the one presented before that says the K-4 does 580-590 km/h at 1.8 ata then there's nothing to argue about really.

 

Yes, that's what I am getting at, based on the data Yo-Yo has, this is what he has come up with, he has seen what you have posted, and still, this is what he believes is the best representation of the Me 109K-4.

[Hummingbird]

I'm not sure I understand, does he have another performance chart or is he saying this is what he believes based on his own calculations? Again no attitude, just seeking clarification.

[NineLine]

I'm not sure I understand, does he have another performance chart or is he saying this is what he believes based on his own calculations? Again no attitude, just seeking clarification.

 

He has more than just a chart. He has reports, testing data, etc. Building an FM is about more than just one piece of evidence, especially something from the 40's. You cant tell me you would be happy to know that an FM was just built off of something as simple as what you posted?

[Hummingbird]

He has more than just a chart. He has reports, testing data, etc. Building an FM is about more than just one piece of evidence, especially something from the 40's. You cant tell me you would be happy to know that an FM was just built off of something as simple as what you posted?

 

Well an FM is more than just top speed, so no I certainly wouldn't be. I've only posted information related to that specific subject.

 

Also if he has K-4 flight testing data for an aircraft with wheel well doors running at 1.8 ata etc. then he should naturally use that. I would never argue against that.

[NineLine]

Well an FM is more than just top speed, so no I certainly wouldn't be. I've only posted information related to that specific subject.

 

There you go.

[javelina1]

So as I understand it, what we should expect (from talking to Yo-Yo) is 580-585 (plausible to reach 590 even). This is what we should see.

 

thanks for checking Sith.

[GrapeJam]

No Sith, there actually is none which back a 580 km/h top speed. Unless he has one newer than this:

 

 

Wasn't this chart done with newer thin bladed prop? The k4 we hvae in game is modeled with the old 9-12159 prop.

[Kurfürst]

Wasn't this chart done with newer thin bladed prop? The k4 we hvae in game is modeled with the old 9-12159 prop.

 

It has both the new thin bladed 9-12199 prop and the 'standard' 9-12159 prop for reference.

[Hummingbird]

It has both the new thin bladed 9-12199 prop and the 'standard' 9-12159 prop for reference.

 

I would love to see the charts that say 580 km/h at SL though, esp. as I find it extremely odd how it could suddenly be 15 km/h lower than on a graph dated 19th of January 1945.

[Kurfürst]

I would love to see the charts that say 580 km/h at SL though, esp. as I find it extremely odd how it could suddenly be 15 km/h lower than on a graph dated 19th of January 1945.

 

Its on the GLC datasheets, also from Messerschmitt data source, the curve is poor quality but visible.

 

IMHO the difference may lay in

 

-the a simplification of GLC in the curve, as it goes straight from SL to 7500 m, which does not accurately portray the 605 power curve, so at some altitudes they likely took mean avarage for speeds

- the fact that the GLC curves are for earlier 605DM powered K-4s (1,75ata / 1800 PS vs 1.8ata / 1850 PS for the 605DB version we have in DCS and in the Projektbüro K-4 curves above)

- some other factor, different source data used etc.

 

I wouldn't complain about anwhere between 580-590 vs the curve's 595 figures, as yoyo says its well within statical error and real life production tolerance, whereas 30+ km/h difference was clearly not. Its also effected by (sometimes not-so)minor factors like radiator position, and atmospheric environment used by YoYo's model vs the Projektbüros results.

 

Apparantly YoYo's previous model was matching well real life 109G-5/AS model results, so its matches a more or perhaps less good quality real plane, only some drag elements were missing for being a true 109K level, which I believe was/being corrected and thus we will no longer have a G-10 :p but a K-4, well maybe made on Friday afternoon, but still, real life examples were each different as well.

[Yo-Yo]

For a long time I stopped myself from posting this chart, because I understood that the faith of many will be broken....

THis is the real chart of maximal speed where the certain results of tests are plotted. To avoid any speculations I have to say that the tests measured results were recalculated to MSA as it is a compulsory requirement for such graphs.

 

As you can see the results dispersion is about 30-33 (+- 2.1%)kph giving the standard dispersion about 5 kph or 0.7% that is very good results for the measurements.

 

But in absolute values.... did it shock you?

 

So do you understand now, why the attempts to pray to 5 or even 10 kph difference is not the thing that causes my nightmares?

[NineLine]

I would love to see the charts that say 580 km/h at SL though, esp. as I find it extremely odd how it could suddenly be 15 km/h lower than on a graph dated 19th of January 1945.

 

Why are you so hung up on one number, when we were given a range of speed, which, in real life is how things really work. You need to loosen up a little. What are the margins of error on those charts? Are those charts estimates (where is the report that created that chart)? What was the purpose of those charts, as in would it have been beneficial to the person making them to lean towards the better results than not. etc etc etc... so many factors you just straight up ignore, I don't get it, you seem so thorough with so many things, then get tunnel vision on others.