Spit/109 sea level speed comparisons in 1.08 beta patch

[5./JG27.Farber]

Originally Posted by camber

Hi Farber,

Sounds like I may be overstating the ease and safety of 1.45ata use in the 109. In my speed tests I tried restarting it a few times at SL and didn't see engine problems but didn't try many variations. I got 450kmh without and 470 kmh with it on, is that consistent with you?. The 1.45ata in combat makes it harder to work out how best to configure the 109 in CoD, if you gave the 109 500kmh at around 1.3ata and combat access to 1.45ata, you have a VERY fast bird indeed in CoD considering historical information.

For the 109 tests I left auto prop pitch on and had the throttle fully open, with the boost regulation giving 1.35ata or 1.45ata. FT is full throttle as you surmise.

I scaled the plots seperately because I wanted to talk about relative speeds in real life and game. Both plots have a 120kmh range on the y axis, the CoD one starts 50kmh lower because all speeds in CoD are roughly 50kmh low. These tests are really a bit basic..only sea level max speeds done singly offline.

Thank you for you intelligent and polite reply. Hopefully it can be an example for this thread so it doesnt get locked.

My squad mates and I have been discussing the difference between the E4 auto pitch and the E1 and E3 manual pitch which is quite different. I would also go as far to say when your using autopitch your almost using the AI FM in some respects. The exact difference is hard to describe and establish exactly... The auto pitch also runs at a lower RPM than I would manually, although it gets more acceleration, better fuel economy and is overall superior except when you rapidly climb and dive continiously and it cannot keep up with you. 5./JG27Gruber could explain more on this than I think, I will see if he wants to contribute.

I can achieve 460kmh sea level with out any wep during the acceleration... Occasionally if I have my aircraft trimmed perfectly and the planets align I can get a steady 480 kmh... At 5km altitude its more like 420kmh.

Klem started a thread about speed and the 109 was discussed also. I made some quick tracks [Strike]which I will attempt to attach here.[/Strike] (they are messed up, I will fraps it and upload to youtube...) Close to sea level tests and 5km level flight speed tests 1.3 Ata and 2350 U/pm if I recall. I think these runs were made in 1.07. As far as I am aware the only difference to the 109 FM is the rad drag... - Which is neglible to a degree.

-Ultimatley, I am only Human. I'm proberbly not the best at flying straight and level and maybe I am even doing it wrong? I will let others be the judge of it.


EDIT1: WOW was I wrong?! 100% Fuel gave some interesting results but I need to test 50% also for comparison. There have been changes to Bf109 FM in 1.08.

[41Sqn_Banks]

Interesting .... http://www.spitfireperformance.com/n3171-cooling.jpg

From: http://www.spitfireperformance.com/n3171.html

[TomcatViP]

I agree there is some drag effect with the rads.

However, do you realize guys that there was no 100oct fuel during BoB ?

Wonder what you are looking after here?!!

Regarding the speed achieved by the tester, isn't it the same one that wasn't able to achieve 270 in a hurri ? I mean teh kind of guy taking off with a cold engine, flying hood open, at 400kph cruise speed and complaining about overheating in combat ?

I think it says it all...

I am sory but when I read "real life MkI 100oct" it really push me out of my brain.

[camber]

Originally Posted by TomcatViP

Regarding the speed achieved by the tester, isn't it the same one that wasn't able to achieve 270 in a hurri ? I mean teh kind of guy taking off with a cold engine, flying hood open, at 400kph cruise speed and complaining about overheating in combat ?

I think it says it all...

I am sory but when I read "real life MkI 100oct" it really push me out of my brain.

Hi Tomcat

Er, not sure if it is an English issue, but that reads like a hilarious insult so I will reply as such.

Maybe I (it) WAS the kind of tester that wasn't able to achieve 270 (mph?) in a Hurri while complaining. But what would you say if it got back to the airfield, abducted Spitgirl from the officer's mess, and took her to the nightspots of Picadilly in an open top Lagonda?

Looking back the only flight test of a Hurri I remember was 240-245mph on the deck in the first beta patch with FM revision (slowing Hurris down). I think it was a fair bit faster in the previous retail patch 1.05.

Will not comment on the fuel with high round number
in case the padlock gods are roused from fitful slumber.

Cheers M8

[NZtyphoon]

Originally Posted by camber

Will not comment on the fuel with high round number
in case the padlock gods are roused from fitful slumber.

Cheers M8

I see ATAG_Dutch has been doing some tests, with interesting results, http://forum.1cpublishing.eu/showthr...624#post457624

[5./JG27.Farber]

I have done the tests using the values in the table for the DB 601 A and B manual. I believe the new compressor is modeled, so in the box "Flying Altitude" I used the left hand column, as there is significant drop off in Ata at 4.5 to 5km rather than 4 to 4.5km... I also performed the test on a multiplayer server in case FM's are different in single player.


Using ATAG_Keller's IAS TAS converter the results are:

Test 1 Sea level 1.3Ata 2400U/pm IAS 440 TAS 440 or 273 mph
Test 2 Sea level 1.23Ata 2300U/pm IAS 430 TAS 430 or 267 mph
Test 3 Sea level 1.15Ata 2200U/pm IAS 420 TAS 420 or 261 mph

Test 4 4500metres 1.3Ata 2400U/pm IAS 400 TAS 518 or 322 mph
Test 5 5000metres 1.23Ata 2400U/pm IAS 390 TAS 518 or 322 mph
Test 6 4900metres 1.15Ata 2200U/pm IAS 370 TAS 489 or 304 mph

http://youtu.be/O4jHSMyYdkg <---- Video of tests.

Now we need to dig out the real life tests and compare.


The effect of WEP also seems to have changed. I tried making it break the engine in the usual ways but could not manage it... It also seems to have effect at all altitudes now.

[TomcatViP]

As I remember it I use to fly with a much higher pitch setting to get speed. You need to increase the blade angle. At alt, it's much around 2k or 2.1k.

Otherwise you can't convert the power of the engine into speed. Maybe there is a need to tweak the game engine.

[bugmenot]

Originally Posted by 5./JG27.Farber

I have done the tests using the values in the table for the DB 601 A and B manual. I believe the new compressor is modeled, so in the box "Flying Altitude" I used the left hand column, as there is significant drop off in Ata at 4.5 to 5km rather than 4 to 4.5km... I also performed the test on a multiplayer server in case FM's are different in single player.


Using ATAG_Keller's IAS TAS converter the results are:

Test 1 Sea level 1.3Ata 2400U/pm IAS 440 TAS 440 or 273 mph
Test 2 Sea level 1.23Ata 2300U/pm IAS 430 TAS 430 or 267 mph
Test 3 Sea level 1.15Ata 2200U/pm IAS 420 TAS 420 or 261 mph

Test 4 4500metres 1.3Ata 2400U/pm IAS 400 TAS 518 or 322 mph
Test 5 5000metres 1.23Ata 2400U/pm IAS 390 TAS 518 or 322 mph
Test 6 4900metres 1.15Ata 2200U/pm IAS 370 TAS 489 or 304 mph

http://youtu.be/O4jHSMyYdkg <---- Video of tests.

Now we need to dig out the real life tests and compare.


The effect of WEP also seems to have changed. I tried making it break the engine in the usual ways but could not manage it... It also seems to have effect at all altitudes now.

http://www.rolfwolf.de/daten/E4/Emil.html


Auszüge aus Flugzeugdatenblatt Bf 109 E-1, E-3 nach L.Dv.556/3


Motor DB601A mit Alter Lader "Old Supercharger"


Höchstgeschwindigkeiten in Steig/Kampfleistung (Diagram)

2300 U/min 1.23 ata



Höchstgeschwindigkeiten in Steig/Kampfleistung (Tabelle)

2300 U/min 1.23 ata

0km                  460km/h

1km                  480km/h

2km                  500km/h

3km                  520km/h

4km                  540km/h

5km                  555km/h

6km                  555km/h

7km                  550km/h

[ACE-OF-ACES]

Originally Posted by 5./JG27.Farber

Which from the minute amount of this information I followed before - I thought as much...

Shame.

Agreed

Originally Posted by 5./JG27.Farber

However hopefully we can come to some kind of accord and present the data to 1c:MG...

When it comes to calculating data.. I am sure 1C can do it as well if not better than any member of this forum.. The math is the math! The only time the math comes into question is when it does not match reality.. And in this case, where we have no reality to compare to, no one can say one way or the other how good the math is doing in simulating the aircraft.

Originally Posted by 5./JG27.Farber

This is the part where we must choose what I would call "Folklore" (eye witness accounts) and "facts" actual graphs... I don't see how you can truly have purely one or the other and I think this is where the real nitty gritty arguments break out...

Considering the fact that people can find a way to argue about the hard data (graphs) it is no wonder they can argue about the folklore.

Originally Posted by 5./JG27.Farber

So with an open mind I am finding myself more in the "feeling" group than the facts but with a balance of both.

The difference is the hard data (graphs) can be reviewed such as to minimize the errors..

Which is not the case with folklore!

There are just too many unknowns associated with the folklore to make it useful. Some people think they can do some statistically analysis of all the folklore and come up with some sort of consensus.. But it is just not the case.. Or should I say that in the past 20 years of flight simming, I have seen many make that claim, but no one has yet do pull it off.

Which is not surprising, in that we are NOT talking about gathering up folklore statements that somewhat agree..

For example, assume 3 WWII pilots said they could climb to 20kft in 9.2min, 10.2min, 9.8min.. And we say, hey that is great, we will just take the average of those three staments and call it good. NOPE! What we have is folklore that is many cases is 180 out! Fore example, there are WWII Spitfire pilots that said they could easily out turn or turn with a Bf109.. At the same time we have WWII Bf109 pilots who say they could easily out turn or turn with the Spitfire.

What do we do in that case?

Flip a coin?

I think not!

That is why most if not all folklore (pilot accounts, pilot action reports, etc) are so useless! In that they typically never provide enough information to even recreate the scenario in the game.

For example, a P51 pilot reports says he got behind a Bf109, closed in on it, and shot it down.

Ok..

Did he dive down from above to get on the 109s six? Or did he climb up to the Bf109? Or was he at co-alt and got in behind the 109? Did the 109 even know the P51 was behind him? Was the 109 pilot wounded and just trying to make it home, was the 109 engine damaged from a previous dog fight that just ended..

The list of un-knows is ENDLESS!

Which is why most if not all folklore is useless when it comes to tweaking the FM! IMHO your better off relying on the math and leaving it at that!

Long story short, typicall folkloare (pilot accounts and reports) tell us alot about the 'men' and thier 'tatics' but they tell us very little about the 'performance' of the planes.

Originally Posted by 5./JG27.Farber

We can have all the facts nailed on the head like ROC and TAS

Most but not all.. In that as I noted above, even with hard data like graphs, there are some unknowns associated with it that can cast doubt on the data..

The funny ones are the folks with double standards that will cast doubt on a test of a plane they don't like but at the same time accept lesser data for the planes they love as proof positive! It would be funny if it was not so sad!

Originally Posted by 5./JG27.Farber

but as you say we are still guessing the rest which is where "folklore" fills the gap...

Disagree

There may be a handful of folklore accounts that are 'useful'

But as noted above, most if not all folklore is useless!

Just to many unknowns!

Not to mention the fact that most if not all pilot reports are ONE SIDED STORIES!

That and they typicall dont include enough info to re-produce the scenario in the game to see if the plane the pilot was flying can do what he said, let alone the fact that we have absolutely no idea of what the state of the other plane and pilot was!

Originally Posted by 5./JG27.Farber

However then we are down to the spit always out turns the 109 and vice versa... - from pilot accounts...

Bingo!

Originally Posted by 5./JG27.Farber

So, its a mine field...

Should we try to get 1c:MG nail the "fact" figures as close as possible and then the "pilot account" things like turn and roll?

No not in my honest opinion, best to rely on the math when there is no real world data to compare to

Originally Posted by 5./JG27.Farber

This is my first forray into a FM debate... So forgive the open mindedness and lack of direction.

No worries!

[camber]

I had a sad 109 experience yesterday. Flying in overcast it is easy to get confused between the top and bottom of the aircraft, leading to the following:

Originally Posted by 5./JG27.Farber

Test 4 4500metres 1.3Ata 2400U/pm IAS 400 TAS 518 or 322 mph
Test 5 5000metres 1.23Ata 2400U/pm IAS 390 TAS 518 or 322 mph
Test 6 4900metres 1.15Ata 2200U/pm IAS 370 TAS 489 or 304 mph

http://youtu.be/O4jHSMyYdkg <---- Video of tests.

Now we need to dig out the real life tests and compare.engine in the usual way
.

Seeing as you are doing some altitude 109 tests I did the same on patch 1.08. It seems not to have changed the last two patches though.

At 5000m 1.23ata 2400rpm I get IAS 400kmh which seems consistent with your Test 5 above.

The 109 does not change max speed between 2100 and 2400rpm which simplifies things.

Messerschmitt "guaranteed" top speed: (backed up by the flight test record)

570kmh TAS @ 5000m, 2400rpm, 1.3 ata (5 min limit).

CloD 109E4 (manual prop pitch) top speeds:

425kmh IAS = 561kmh TAS @5000m, 2400rpm, 1.32 ata

Full throttle boost has dropped below 1.35ata at 5000m. However the 109 1 minute takeoff boost is still working and oddly enough will still increment boost at 5000m (to 1.42ata).

440kmh IAS = 581kmh TAS @5000m, 2400rpm, 1.42ata.

So the CloD 109E4 at 5000m is 10kmh slow at the 1.3ata combat setting (will assume boosts in the 1.3-1.35ata range can be considered effectively the same). However it has access to the takeoff boost at altitude, which enables it to be 10kmh faster than the real life version.

Cheers, camber

Offline tests, cockpit off, speeds rounded to 5kmh, 4950-5050m, oil/water rads fully open, OAT 25/1000ft rule for IAS/TAS conversion.