72"

[Echo38]

I'm not saying the 109 accelerates harder, but it should be tested.

 

It does, and it should. (By a large margin—much larger than that in the top speeds.) The 109 is draggier, but has a much better thrust/mass. So, the 109 reaches its approximate top speed much sooner than the P-51 does, in level flight. This means that the 109 is faster than the P-51, for however long it takes to get to that point, if they both started out at similar speed (e.g. both began the race at best climb speed). The 109 can even begin the race at a lower speed, then pass the P-51's speed, and remain faster for at least a full minute.

 

Were there other changes to go along with the 72"? Like better cooling?

 

No, no better cooling, other than airflow increase from increased top speed (but, as mentioned, the speed increase is smaller than the power increase, because drag). The only difference is an adjustment to the engine's governor(s) and filling it with 100/150 grade avgas instead of 100/130.

Edited April 28, 2017 by Echo38

[BuzzU]

It does, and it should. (By a large margin—much larger than that in the top speeds.) The 109 is draggier, but has a much better thrust/mass. So, the 109 reaches its approximate top speed much sooner than the P-51 does, in level flight. This means that the 109 is faster than the P-51, for however long it takes to get to that point, if they both started out at similar speed (e.g. both began the race at best climb speed). The 109 can even begin the race at a lower speed, then pass the P-51's speed, and remain faster for at least a full minute.

 

That's the point I was trying to make. Even though the P-51 has a higher top speed. The 109 can still catch it, because of better acceleration.

 

Thanks.

[Echo38]

The Mustang's serious mass advantage over the 109 will prevail at any altitude, if you keep it fully fueled and fight to your advantage.

 

Sorry to bring up something from a few days ago, but I just realized, while thinking about level speed acceleration, and then dive acceleration: without drag, all objects are supposed to fall at the same speed, regardless of their mass, yes? So the P-51 shouldn't dive any better with a full tank a fuel than it does empty. The P-51's superior diving ability over the 109 comes from the P-51 being less draggy, not from being more massive. Mass can only be an advantage for an airplane in the case of momentum, which only comes into play during a zoom climb (and even here, superior thrust/mass is surely more of an advantage than simply having more mass for momentum).

[OnlyforDCS]

Yes my point was mostly to do with momentum and BnZ. Which is how you should be fighting the 109 in the Mustang.

[Echo38]

Even in B&Z, greater mass is a disadvantage, rather than an advantage, in almost all cases. Again, there's a window during the zoom climb where I can maybe see mass being an advantage (from the level point of the pullout, to somewhere between then and the best sustained climb speed), 'coz momentum, but that's the only time I can think of that you might want to turn the mass dial up, so to speak. And even in a zoom climb, it's better to have a high thrust/mass than to have a high mass. Since higher mass means worse thrust/mass, all else equal, I'm not sure that the extra mass "pays for itself" even in this one case.

 

If the airplane had its engine stopped, then the more massive airplane would end up in a better position (compared to the less massive airplane, all else equal) after a dive and subsequent zoom climb. But we're putting loads of energy into the situation via our engines, and that changes things quite a bit. Physics experts, what say you?

 

Addendum: I watched Otto's level speed test, and noticed two things which could have affected the results: the 109 looked more wobbly than the P-51, and the slip&skid indicators were not visible. The latter is all-important for a speed test. I don't have DCS updated to 1.5x; can someone take a look at the track and keep an eye on the ball?

Edited April 28, 2017 by Echo38

[otto]

 

Addendum: I watched Otto's level speed test, and noticed two things which could have affected the results: the 109 looked more wobbly than the P-51, and the slip&skid indicators were not visible. The latter is all-important for a speed test. I don't have DCS updated to 1.5x; can someone take a look at the track and keep an eye on the ball?

 

Look this will be my last response because i have better things to do.The 109k in this sim has a lot more torque than any other sim and you have to counter that constantly the p51 doesn't and is much more stable(Oh my god the p51 actually has an advantage over the 109 :D).No laminar flow means more turbulence and the list goes on.

 

I would say it will take some exponentially better flying to get within 10km/h of the p51's top speed in my video with the 109 but if someone can do it and post a new better test that's great :thumbup:.

I would say it pretty much not logical to presume the 109 to be faster because of the reasons i mentioned in my early posts but if someone manages to make a track or video of that than more power to him.

Edited April 28, 2017 by otto

[BuzzU]

I'm not sure how the DCS 109 is, but when I fly the 109 in other sims all it has is elevator trim. So, it's hard to fly perfectly level all the time. Any throttle change affects how it's trimmed.

 

I doubt the little wobbling in the video affected the speed that much. The P-51 has a higher top speed, but the 109 may still catch it because of better acceleration. Good enough for me.

[Echo38]

Any throttle change affects how it's trimmed.

 

There shouldn't be any throttle changes in a level speed test.

 

I doubt the little wobbling in the video affected the speed that much.

 

I'm not as concerned by the wing-waggling as I am by the hidden slip&skid indicator. That 109 could have been in a pretty significant slip, with no way for the viewer to tell. Even a small slip can make a large difference in speed.

[BuzzU]

I understand, but since there's only rudder trim by the ground crew. It's usually centered pretty close.

 

Of course, i'm guessing since I don't have the plane. Maybe i'll buy it on the next sale. I actually do like the plane.

[Solty]

The p51 is faster.It is really obvious why: two planes with the same horsepower but one has laminar flow wing.You don't have to be Einstein.

 

p2oHFITX-Og

 

At first the 109 accelerates better from the lower speed but than the speed difference is about 20 km/h in favor of the P51.

 

I've also flown the p51 until the engine blew and it took some stupid flying to do that.It's in the track.

 

Feel free to make your own test but like i said : Unless there's a bug there's no way a plane with laminar flow wing will be slower than one without considering both planes have same horsepower.

 

Your test is severely flawed. Firstly you show us IAS (should be TAS use Ctrl+Y to switch), secondly you do not tell us conditions (temp, pressure, weight, power), thirdly both airplanes are not trimed for level flight and finaly you are suppose to get to the max speed by acceleration and not by dive. Not to mention that each of those tests should be done at least few times to be sure.

 

-----------------------

This is my post with full tests of the P-51D in game. Seems to be still relevant but I will make new ones just to be sure.

https://forums.eagle.ru/showpost.php?p=3062437&postcount=34

Edited April 28, 2017 by Solty

[Zilch]

Wow...I'm off this thread for a few months, half expecting some resolution by now. The debate about manifold pressure still rages, I see?

 

Only on the ED forums. Ah, what a place.

 

I mean that in a good way. I've never learned and unlearned so much about such a specific topic anywhere else.

 

So, about those G-suits...any news on this? Seems like reasonable feature to add, based only on historical accuracy. It was super effective back in the day. I read stories about Mustangs with G-suited pilots landings with increased dihedral angles because the pilots could withstand many more G than the otherwise, and the pilots found out that they could get a lot more out of the Mustang, surprising opponents who were not expecting that kind of turn performance.

 

Any word from ED on this? Given the choice between the controversial 72" manifold and the G-suit, my preference would be the suit for both historical and game play reasons.

[otto]

Wow...I'm off this thread for a few months, half expecting some resolution by now. The debate about manifold pressure still rages, I see?

 

Only on the ED forums. Ah, what a place.

 

I mean that in a good way. I've never learned and unlearned so much about such a specific topic anywhere else.

 

So, about those G-suits...any news on this? Seems like reasonable feature to add, based only on historical accuracy. It was super effective back in the day. I read stories about Mustangs with G-suited pilots landings with increased dihedral angles because the pilots could withstand many more G than the otherwise, and the pilots found out that they could get a lot more out of the Mustang, surprising opponents who were not expecting that kind of turn performance.

 

Any word from ED on this? Given the choice between the controversial 72" manifold and the G-suit, my preference would be the suit for both historical and game play reasons.

 

I've asked ED about it a long time ago .I actually thought it was added .

[Echo38]

Given the choice between the controversial 72" manifold and the G-suit, my preference would be the suit

 

How is 72" controversial? It's well-documented to have been officially authorized and extensively used in combat. There are few who argue that it shouldn't be in the sim. There's little controversy on the matter. There's also no reason why having both 72" WEP and the G-suit would be a bad thing.

[Zilch]

How is 72" controversial? It's well-documented to have been officially authorized and extensively used in combat. There are few who argue that it shouldn't be in the sim. There's little controversy on the matter. There's also no reason why having both 72" WEP and the G-suit would be a bad thing.

 

Well, the thread is going on 19 pages. :) That's all I meant.

[David OC]

To me, it's still all good here either way, add them, don't add the extras. It's not going to make a huge difference to most pilots in the sim, and if it does, it would be 1 in 500 kills (speculating). There will also be those pilots in the sim that are just that good (gifted) at using this "simulated aircraft" for both aircraft, that it just seems like they have a massive advantage when they don't. It comes down to where the fight takes place and who gets the advantage 1 vs 1 that's all.

 

When your low in the P-51, that's your first mistake right there, the aircraft was not design for this type of 1 vs 1 battle, unless of course you have a good trained wingman and or second element with you, tactics won the air war, not a single P-51 on the deck.

 

You are trying to massage a time in history to make the P-51 into something it wasn't designed and built for, just to create a "very unique" 1 vs 1 even competition on the deck.

 

So if anything, just give the P-51 back the G-Suit, for the one in 500 times it might get you out of trouble when you're silly enough to be on the deck 1 vs 1 against a pilot as skill as you are in a 109.

 

Yes the P-51 is king at very high altitudes. Use that to your advantage to dogfight. As always do not go in a vertical dogfight against a 109, he's the king there. At lower altitudes do not go 1 on on 1 with a 109 or 190. Bring a friend

 

For me the biggest challenge in flying the P-51 is other P-51 pilots. It only takes 2 or 3 P-51s flying CAS who don't mind dying every time to drag the fight down to the deck, where the 109s snack on them like an aperitif. https://forums.eagle.ru/showthread.php?t=134840

 

 

It's going to be interesting when the P-47 is available

 

Quote

"The German fighter pilot under attack would perform a split-S maneuver to dive away from combat, a maneuver that worked very well against opposing fighters early in the war. Such an action against a Thunderbolt, however, would be a deadly choice because the P-47, being very heavy and powered by a 2,000 horsepower engine could out-dive any other fighter in the sky.

 

Fighter Group 56, which flew the P-47 throughout the war and achieved more air-to-air victories than any other unit in Europe, was particularly adept at this strategy. The top scoring ace in the European Theater, Col. Frances Gabreski of the 56th, brought down 28 German aircraft with his Thunderbolt."

 

This quote above was from this thesis I found about the P-51

http://etd.lsu.edu/docs/available/etd-07022008-013657/unrestricted/courter_thesis.pdf

 

This same debate will happen with the P-47 when some will try and battle it out on the deck with the 109 or 190.

 

-

Edited April 29, 2017 by David OC

[Echo38]

So if anything, just give the P-51 back the G-Suit, for the one in 500 times it might get you out of trouble when you're silly enough to be on the deck 1 vs 1 against a pilot as skill as you are in a 109.

 

Seriously? The G-suit helps at high altitude, not low. You can't pull enough Gs to black out in sustained turns. The G-suit helps more up high, where you have enough energy to keep up a hard instantaneous turn.

 

Meanwhile, the 72" WEP rating helps the most down low. And however could you possibly think that 3% more speed would mean only 0.2% more survival chance?!

 

Why are you trying so hard to downplay the significance of the 72"?

Edited April 29, 2017 by Echo38

[David OC]

Like I said at the top, add both, I still don't think this would help the average pilot by 1% if he stays on the Deck and at most it might give a pro 3% gain in some strange 500 to 1 circumstance, because he shouldn't be using the P-51 alone on the deck in the first place.

 

You really need to set a hard deck for a 1 vs 1 competition for the P-51 vs Bf 109 to even up the overall design of these two aircraft.

 

I'm not biased either way here, I just think this change to fight the P-51 on the deck is only going to benefit the elite 1% for a match-up that should not take place at sea level in the first place.

[OnlyforDCS]

Even in B&Z, greater mass is a disadvantage, rather than an advantage, in almost all cases.

 

Nope, that is wrong. Momentum allows a fighter the ability to retain energy more efficiently. That means that a low drag, high speed fighter like the Mustang can maneuver more efficiently in a BnZ, allowing him to quickly gain on a lighter maneuvering target, or quickly escape a lighter enemy on his six.

 

Momentum is one of the most important concepts in energy fighting with WWII fighters, where thrust to weight ratios are comparatevely low compared to modern fighters.

Edited April 29, 2017 by OnlyforDCS

[OnlyforDCS]

Your test is severely flawed.

 

He actually took the time to do and record this test. Have you done that? Or are we supposed to take your word for it.

 

Firstly you show us IAS (should be TAS use Ctrl+Y to switch)

 

TAS = IAS at Sea level. Or are you claiming differently? (assuming no wind) Eather way it doesn't matter. The relative speed difference is all that matters, and if we take into account that both fighters are flying through the same airmass then IAS is perfectly fine.

 

, secondly you do not tell us conditions (temp, pressure, weight, power)

 

Both are running at full power. As for conditions, I assume they are the same. Why would they not be run in the same conditions? Are you suggesting Otto would falsify temperature and pressure so that the P51 comes out on top?

 

, thirdly both airplanes are not trimed for level flight

 

The P51 is trimmed out perfectly. The 109 is kind of wobbly, which means its inducing some drag. How much is a matter of debate. Is it 20km/h worth of drag? I don't think so, but I agree better trim is needed for another test.

 

and finaly you are suppose to get to the max speed by acceleration and not by dive.

 

That makes no difference to their top speeds. None at all. This is physics 101, common!

 

 

Not to mention that each of those tests should be done at least few times to be sure.

 

I agree. Care to make a repeat test and post the results?

Edited April 29, 2017 by OnlyforDCS

[otto]

SPEEDTEST 2

 

I wasn't thinking on doing another one but what the hell it was fun:

 

4sjx2H30f0M

 

109 is trimmed,The p51 isn't but even so the p51 is faster by 10-14 km/h.

Also I've flown the p51 last and my hand was tired.

Conditions DCS default, no wind.TAS ,IAS will not make the 109 faster.

Edited April 29, 2017 by otto

[BuzzU]

To me, it's still all good here either way, add them, don't add the extras. It's not going to make a huge difference to most pilots in the sim, and if it does, it would be 1 in 500 kills (speculating). There will also be those pilots in the sim that are just that good (gifted) at using this "simulated aircraft" for both aircraft, that it just seems like they have a massive advantage when they don't. It comes down to where the fight takes place and who gets the advantage 1 vs 1 that's all.

 

When your low in the P-51, that's your first mistake right there, the aircraft was not design for this type of 1 vs 1 battle, unless of course you have a good trained wingman and or second element with you, tactics won the air war, not a single P-51 on the deck.

 

You are trying to massage a time in history to make the P-51 into something it wasn't designed and built for, just to create a "very unique" 1 vs 1 even competition on the deck.

 

So if anything, just give the P-51 back the G-Suit, for the one in 500 times it might get you out of trouble when you're silly enough to be on the deck 1 vs 1 against a pilot as skill as you are in a 109.

 

 

 

 

 

 

It's going to be interesting when the P-47 is available

 

Quote

"The German fighter pilot under attack would perform a split-S maneuver to dive away from combat, a maneuver that worked very well against opposing fighters early in the war. Such an action against a Thunderbolt, however, would be a deadly choice because the P-47, being very heavy and powered by a 2,000 horsepower engine could out-dive any other fighter in the sky.

 

Fighter Group 56, which flew the P-47 throughout the war and achieved more air-to-air victories than any other unit in Europe, was particularly adept at this strategy. The top scoring ace in the European Theater, Col. Frances Gabreski of the 56th, brought down 28 German aircraft with his Thunderbolt."

 

This quote above was from this thesis I found about the P-51

http://etd.lsu.edu/docs/available/etd-07022008-013657/unrestricted/courter_thesis.pdf

 

This same debate will happen with the P-47 when some will try and battle it out on the deck with the 109 or 190.

 

-

 

That thesis is a good read. Thanks for posting it.

[BuzzU]

SPEEDTEST 2

 

I wasn't thinking on doing another one but what the hell it was fun:

 

4sjx2H30f0M

 

109 is trimmed,The p51 isn't but even so the p51 is faster by 10-14 km/h.

Also I've flown the p51 last and my hand was tired.

Conditions DCS default, no wind.TAS ,IAS will not make the 109 faster.

 

 

Thanks for doing the test again. At one point they were both doing exactly the same speed and level. The P-51 is a bit faster. Not sure if it's any kind of advantage in a dogfight it's so small.

 

I feel acceleration in level, diving, and climbing are more important. Turning shouldn't be important if the pilot flies the P-51 as it should be.

[OnlyforDCS]

At one point they were both doing exactly the same speed and level.

 

Yes they were both coming out of their dives at that point, so this speed isn't representative of their level top speed, which is why it went down once the planes flew straight and level for a while.

[Andy1966]

It's going to be interesting when the P-47 is available

 

yes it will. the first time a jug dives in from 10 or 12 thousand feet AND turns with a 109 while he's being flamed then helplessly watching the jug zoom climb away will most likely cause a change of tactics on the axis side

[OnlyforDCS]

Yes, I can't wait for the P47D. Though the tactics used shouldn't change that much from the Mustang.

 

Unfortunately the biggest problem is the damage modeling, followed by the visibility issue. You can't dive on a target you can't see :)