DCS Spitfire Mk IX performance

[gavagai]

Speed effect may not be so great (say 10 mph on these selected altitude bands), but effect on climb is very significant.

 

Alright, you've made a fair point. This is why we have these discussions, after all.

 

I'm not so concerned about the high altitude performance, but having the supercharger switch at the correct altitude is a big deal. That 1500ft difference is something we'll experience almost every time we fly it.

[NineLine]

Other people may get their panties in a bunch over which block number the P-51D is, but it makes literally NO DIFFERENCE when it still has late 1943 performance.

 

And that goes for the Spitfire LF Mark 9, too.

 

I'll make this real simple. I have no desire, incentive, or impetus to buy a 1943 plane (not to mention TWO of them) when they are competing against 1945 planes.

 

 

Introduce mid-1944 engine settings for either of them so they can at least begin to compete against the 1945 planes, then I'll open my wallet. Or introduce 1945 planes to fight against them. One or the other.

 

You stated already you are not interested in this version of the Spitfire, you dont need to have that same post on each new page of this thread, its really not helpful.

[gavagai]

Only trouble I have with this kind of post is simply, Yo-Yo posts data based on an FM derived from many many hours of research and collected data, and your opinion is based on lots of "I thinks".

 

What? Cite the offending text, please. I don't read that at all in Kurfurst's posts.

 

The supercharger stages are right there in the graphs.

Edited March 24, 2016 by gavagai

[Danneskjold]

You stated already you are not interested in this version of the Spitfire, you dont need to have that same post on each new page of this thread, its really not helpful.

 

I was replying to someone who replied to me, and trying to convince Eagle Dynamics that it's downright silly and ill conceived to introduce more 1943 performance in a 1945 team death match.

 

The solution is simple, and will drive up sales. I don't know why you guys haven't already made that change, and are in fact making the same mistake again.

[Yo-Yo]

I do not believe in this measurement error, its a rubber arguement anyway, fits all situations and sizes. And these measurement errors only show in the two references chosen - the prototype and the experimental plane...?

 

Yes, thats the point (hsitoric charts also gave it as 20 000 Feet with 400 mph RAM).

Normally measured range of FTH with serial production Spits cc 19.5-20k feet. Only prototype BS 543 and experimental MA 648 is higher, both stated in report, why (carburetor changes - not serialized apparently)

 

The 23k feet is actually my (rough) reading from your first curve on DCS model Spit. Second shows it closer but bit above even BS 543.

 

My question is why is DCS Mark IX full throttle height (and resulting performance) cc. 2500-3000 feet higher than

 

a) measured in real life on all serial production IX LFs or VII/VIIILFs - expect the two proto/experimental planes oddly chosen as references

b) theoriatically possible with cc 404 mph ram shown by your calculation

c) theoriatically possible with 400 mph ram shown by WW2 RAF calculation for Merlin 66

 

If you say 3000 feet deviation in full throttle height is small difference - sure, please increase then the FTH of existing prop jobs by this amount. See what gives from that... ;)

 

P.S. Yes weight does have very minimal at low/medium altitudes but its the high altitude (FTH and above) I am talking about where this effect is increasingly important. See graphically this chart for the 109 http://kurfurst.org/Performance_tests/109G_Leistungzusammenstellung/LZS109G_Blatt23_weight-effect_speed.jpg

 

Since the DCS model increasingly diverges from the reference, I guess its worth checking wheater this is because DCS current pre-FM models 100% weight based on raw data for 95% weight.

 

I tried to explain why this point is plotted at this place. Because the tests were performed at 1,2 ,3 km. I did not specially look for the exact FTH. So, the spreadshit linked the points as it does. Better, I'd rather leave the points without a line. As an experimental points. Just to show how they fit the lines.

 

Regarding the measurements... I wrote about the methods - to use available in-cockpit instruments.

If you were an engineer and performed at least a couple of mesurements you would understand me.

 

The problem of the measurement accuracy is the fundamental.

 

Just take a look at the IAS instrument - what is the scale unit there? Especially at the 350-400 mph range...

 

Then, get any rigid rectangular thing having 20-30 mm length, a measuring tape and try to measure this size. Right down your result in mm with two digits after a point (he-he)... you can even perform a dozen of trying and get an average.

 

Then get this one

 

 

and measure ACCURATE size. Enjoy...

[NineLine]

I was replying to someone who replied to me, and trying to convince Eagle Dynamics that it's downright silly and ill conceived to introduce more 1943 performance in a 1945 team death match.

 

The solution is simple, and will drive up sales. I don't know why you guys haven't already made that change, and are in fact making the same mistake again.

 

This is what its going to be. They build these modules based on the available information they have. This is the IX they feel comfortable doing. It will be fine, just like all the other aircraft are.

 

You guys are sweating something you dont even have your hands on yet, or tried to be able to compare with what we have currently... its the only thing downright silly currently.

 

Now please, the topic is the DCS IX performance, please stay on it.

[Kurfürst]

Only trouble I have with this kind of post is simply, Yo-Yo posts data based on an FM derived from many many hours of research and collected data, and your opinion is based on lots of "I thinks".

 

All correct expect my opinion is actually based on, oh wait, times goes so fast, 16 years of "I think" - research & analysis - and I know the BS 543 and MA 648 tests details very well and would never use them as straight reference.

 

And if I see data that matches them, "I think" I know where the problem might be.

 

You are getting too hung up on the comparison charts, you should ignore what he used as a comparison, I think that is throwing you, I am pretty sure the comparison aircraft where not what the FM is based from, but simply a way to to illustrate where the DCS FM falls with some real world examples.

 

OK - then let me put my point plainly - the current DCS figures only fit the full throttle height characteristics two planes, a prototype, and an experimental setup.

 

It does not fit in with any of the serial production planes FTH characteristics tested and I am pretty sure even back they could measure altitude with better than +/- 3000 feet accuracy.

 

The fact that the DCS model closely matches these proto/experimental planes suggest they were used as a basis for performance model. And if this is true, it is simply a very much possible source of multiple small errors in the FM I wished to point out in detail and I leave it at that whether they are fixed, modified or left as is.

 

If its not true, we are left that the DCS model does not fit results of serial production planes as of yet, for an unknown reason.

[NineLine]

All correct expect my opinion is actually based on, oh wait, times goes so fast, 16 years of "I think" - research & analysis - and I know the BS 543 and MA 648 tests details very well and would never use them as straight reference.

 

And if I see data that matches them, "I think" I know where the problem might be.

 

 

 

OK - then let me put my point plainly - the current DCS figures only fit the full throttle height characteristics two planes, a prototype, and an experimental setup.

 

It does not fit in with any of the serial production planes FTH characteristics tested and I am pretty sure even back they could measure altitude with better than +/- 3000 feet accuracy.

 

The fact that the DCS model closely matches these proto/experimental planes suggest they were used as a basis for performance model. And if this is true, it is simply a very much possible source of multiple small errors in the FM I wished to point out in detail and I leave it at that whether they are fixed, modified or left as is.

 

If its not true, we are left that the DCS model does not fit results of serial production planes as of yet, for an unknown reason.

 

So show what it should look like, plot a chart or share one on how you think it should be, back it up with data, ect. I am sure Yo-Yo will admit all his mistakes and make the FM you expect.

[Danneskjold]

This is what its going to be. They build these modules based on the available information they have. This is the IX they feel comfortable doing. It will be fine, just like all the other aircraft are.

 

You guys are sweating something you dont even have your hands on yet, or tried to be able to compare with what we have currently... its the only thing downright silly currently.

 

Now please, the topic is the DCS IX performance, please stay on it.

 

So if I dig up 150 octane performance for the Spit LF 9, you'd build it?

 

You should have said so, that stuff isn't too difficult to dig up.

[NineLine]

So if I dig up 150 octane performance for the Spit LF 9, you'd build it?

 

You should have said so, that stuff isn't too difficult to dig up.

 

You should go ahead and make a team and build it yourself, this is what ED is doing. Sooner you accept that, the better its going to be for you.

[Yo-Yo]

Regarding the performance curves cluster:

the engineers's task is to estimate where is a significant accordance in the resulsts and where are fallen out points due to certain reasons.

one can see that all experiments except JL.165 cover +- 4...5 mph zone, so we can suggest that there were some reasons of this behavior - engine adjustment, airframe condition, measurements SYSTEMATIC errors, I do not know.

 

 

Is the data from the yellow page for the serial production? If so - the points are red-yellow diamonds. Enjoy.

Edited March 24, 2016 by Yo-Yo

[Kurfürst]

So show what it should look like, plot a chart or share one on how you think it should be, back it up with data, ect. I am sure Yo-Yo will admit all his mistakes and make the FM you expect.

 

I already said in first posts that the BS 310 tests should be what it looked like - after all the Brits accepted that as the "official" figures for this type. I am sure YoYo has that, but its his call.

[NineLine]

I already said in first posts that the BS 310 tests should be what it looked like - after all the Brits accepted that as the "official" figures for this type. I am sure YoYo has that, but its his call.

 

I dont think you are understanding how these FMs are built, its very possible to take all the recorded data from WT testing and such, and have results that differ from different charts across the interwebs, you should know that right? Are you happy with the 109K-4?

 

Again, these charts are not so much reference, than they are to qualify that the data entered into the the sim are generating numbers that are expected. He is not trying to model experimental aircraft.

 

The BS 310 line is on those charts... it looks pretty close to me, I am not sure I understand what the concerns are? because they are not an exact match?

Edited March 24, 2016 by NineLine

[Kurfürst]

I sure do not have intricate knowledge of it, though I think I get the basics of the process. However, I do not think that the

 

"full throttle height in the model seems to be about 3000 feet too high, here is why"

 

is such a complicated message either. I am not talking about absolute speeds (though that is indirectly effected), nor comparison charts, nor margins of error in the measurement - nor any assumptions on my alleged lack of background in doing engineering measurements for that matter... and yes, I am quite happy with my 109K since its no longer a 109G. :p

 

Anyway, that's just my point and I have made it already.

Edited March 24, 2016 by Kurfürst

[Yo-Yo]

I sure do not have intricate knowledge of it, though I think I get the basics of the process. However, I do not think that the "full throttle height in the model seems to be about 3000 feet too high, here is why" is such a complicated message either. I am not talking about absolute speeds (though that is indirectly effected), nor comparison charts, nor margins of error in the measurement - nor any assumptions on my alleged lack of background in doing engineering measurements for that matter... and yes, I am quite happy with my 109K since its no longer a 109G. :p

 

Anyway, that's just my point and I have made it already.

 

And it only means that any reasonable opinion can be admitted. But it does not mean that any incoming opinion is reasonable... :)

[Kurfürst]

So, is the opinion that full throttle height in the model seems to be about 3000 feet too high reasonable?

[KansasCS]

@yoyo, just out of curiosity, could plot the P51,109 and 190 curves into that?

So we can get an idea of what we can expect?

 

 

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[Hiromachi]

I still would like to ask Yo-Yo for the turn time and turn radius data for Spitfire IX. Based on current discussion it seems that Spitfire has a lot of energy and should have a very good maneuverability. But knowing specifics is always nice, hence the polite request.

Edited March 24, 2016 by NineLine
removed OT

[Kurfürst]

I still would like to ask Yo-Yo for the turn time and turn radius data for Spitfire IX. Based on current discussion it seems that Spitfire has a lot of energy and should have a very good maneuverability. But knowing specifics is always nice, hence the polite request.

 

For what is worth, IIRC the Soviet tested in real life one of the thousand IX LFs they received and found the turn radius to be 235 m (IIRC) and the turn time 18 seconds at 1000 meter altitude.

[Hiromachi]

Yes, I'm aware of real life tests Kurfurst. Still, thank you for pointing this.

[nervousenergy]

We need allied medium or heavy bombers to do much else right now. The focus on almost all of these planes were either defending or attacking the bomber stream. The spit was obvioulsy more of an air superiority dogfighter, but i'm not sure what role it had in '44.

 

The P-47 will have a lot of fun attacking ground targets.

 

I enjoy reading these technical discussions, but I'm most interested in when I can buy it. :)

[Yo-Yo]

So, is the opinion that full throttle height in the model seems to be about 3000 feet too high reasonable?

 

No, and I wrote why.

Look at the picture if I were not clear explaining the matter.

Are you happy now?

Edited March 24, 2016 by Yo-Yo

[Pilum]

I don’t have time for anything more than a quick post today but I want to get in that I think the speed and ram boosted FTH in the figures Yo-Yo posted look all right to me:

 

Did some quick C++ simulations runs with the Merlin 66 at +18 boost at 15 deg C for a production model Spitfire Mk9 and got the following numbers:

 

Max speed SL: 538 Km/h or 334 mph

 

Max speed at ram boosted FTH: 668 km/h at 6.6 Km altitude or 415 mph at 21700 ft altitude

 

So to me it looks like the DCS Mk9 model is pretty close to what one could expect! :thumbup:

[Solty]

We need allied medium or heavy bombers to do much else right now. The focus on almost all of these planes were either defending or attacking the bomber stream. The spit was obvioulsy more of an air superiority dogfighter, but i'm not sure what role it had in '44.

 

The P-47 will have a lot of fun attacking ground targets.

 

I enjoy reading these technical discussions, but I'm most interested in when I can buy it. :)

Spitfire is not an air superiority fighter (ASF), that would be closer to P38, P47 and P51 which can actually win superiority over enemy territory because they can stay long enough in the air.

 

Spitfire is a pure and typical European interceptor. Short range, low fuel, great ROC.

[DSR_T-800]

Mmm... the Spitfire at 18 lb has equal energy with 109K with MW50. Will you feel good as you know that at 25 lb you have superiority over your opponent? :)

 

What do you mean by "equal energy"? One would think the Spitfire would be more competitive with 25 lb to have an distinct advantage over all fighters in rate of climb. Also since the Spitfire would be the slowest out of all the fighters including the P-47D-30, ~337mph vs 345mph @ SL. Even with 25 lb boost the Bf-109K4 and Fw-190D9 would still be faster.