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Legioneod

150 Fuel for P-47

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Posted (edited)

Really like the new addition of 150 fuel for the Spitfire and P-51, it's a very nice addition and I was surprised to see it added. I was hoping that the P-47 would have the modification as well but I was disappointed to see it was not included. 

Any chance we will see it added for the P-47 in the future? Imo it would be a logical addition and would give more benefits than just a higher MAP and top speed.

 

I understand things are busy and yall are working on getting Bodenplatte and the other expansions released but hopefully once everything settles down a bit yall can consider adding it.

I was also surprised to see the P-38 didnt have 150 fuel either.

 

This isnt really a complaint though I was disappointed, I'm just hopeful we'll see it in the future.

Edited by Legioneod
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Not too hard to figure out why. 9th AF never used 150 octane fuel and P47s -P-38s were mostly just used on air-to-ground role in 44-45.

2ndTAF did use 150 octane fuel from jan.45 on which is why the Spit IX has it.

I am guessing the 150 octane P-51 is supposed to represent 8th AF escorts, since 9th AF P-51s never used it.

I have no problem with the choices the Devs made.

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On 10/5/2019 at 3:10 PM, Sgt_Joch said:

Not too hard to figure out why. 9th AF never used 150 octane fuel and P47s -P-38s were mostly just used on air-to-ground role in 44-45.

2ndTAF did use 150 octane fuel from jan.45 on which is why the Spit IX has it.

I am guessing the 150 octane P-51 is supposed to represent 8th AF escorts, since 9th AF P-51s never used it.

I have no problem with the choices the Devs made.

8th AF P-47s flew over the area as well (mostly from the 56th FG)

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Posted (edited)

 

 

 Hello @Legioneod I am disappointed by the current 100 fuel performance of the P-47. 

 

The plane is not powerful and robust. It’s not normal that no rudder trim is necessary on takeoff at full power with very little rudder trim for the R2800 Powerplant! It’s a real joke! It feels anemic.

 

The Damage model is also questionable. It takes the same pounding as a FW and BF-109 and many pilot accounts attest to the punishment it could take. 

 

  BodenPlatte is still not finished but I hope they improve the P-47. I look forward to flying the DCS model once it comes out!

 

We need to post in the suggestions thread.

Edited by BSS_Ripper*

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8 minutes ago, BSS_Ripper* said:

 

 

 Hello @Legioneod I am disappointed by the current 100 fuel performance of the P-47. 

 

The plane is not powerful and robust. It’s not normal that no rudder trim is necessary on takeoff at full power with very little rudder trim for the R2800 Powerplant! It’s a real joke! It feels anemic.

 

The Damage model is also questionable. It takes the same pounding as a FW and BF-109 and many pilot accounts attest to the punishment it could take. 

 

  BodenPlatte is still not finished but I hope they improve the P-47. I look forward to flying the DCS model once it comes out!

 

We need to post in the suggestions thread.

The P-47D-25 we have in game matches the climb and top speed of the real thing very closely. From that I surmise that the engine output at the various power settings is accurate.

No plane in the sim we have at the moment requires rudder trim to take off, but it helps. Honestly I think its just that the rudder is very effective at low speeds in this sim, and we can make high rudder deflections much easier than real pilots so the torque can't get away from us as easily.
 

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How do you confirm top speed?

 

Maximum true air speed at 7000 m (22960 feet), engine mode - WEP: 700 km/h (435 mph)

 

Have the developers confirmed the distances of each square in the map? If so then I can use distance = velocity x time reformulated to calculate Velocity

 

I’m a holder of a CPL ME IR in the real world. The biggest plane I have flown though is a Piper Aztec E with 250 hp normally aspirated engines per side.  I have never had the privilege of flying a war bird cheers!

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Posted (edited)
10 hours ago, RedKestrel said:

The P-47D-25 we have in game matches the climb and top speed of the real thing very closely. From that I surmise that the engine output at the various power settings is accurate.

No plane in the sim we have at the moment requires rudder trim to take off, but it helps. Honestly I think its just that the rudder is very effective at low speeds in this sim, and we can make high rudder deflections much easier than real pilots so the torque can't get away from us as easily.
 

We have the D-28 not D-25. D-25 had the Hamilton Prop and was slightly faster in level speed and climb iirc.

10 hours ago, BSS_Ripper* said:

 

 

 Hello @Legioneod I am disappointed by the current 100 fuel performance of the P-47. 

 

The plane is not powerful and robust. It’s not normal that no rudder trim is necessary on takeoff at full power with very little rudder trim for the R2800 Powerplant! It’s a real joke! It feels anemic.

 

The Damage model is also questionable. It takes the same pounding as a FW and BF-109 and many pilot accounts attest to the punishment it could take. 

 

  BodenPlatte is still not finished but I hope they improve the P-47. I look forward to flying the DCS model once it comes out!

 

We need to post in the suggestions thread.

P-47 level peed performance is pretty close to real numbers. It's main drawback is the damage model and control effectiveness at high speeds which imo are incorrect based off of rl accounts.

Also the fact that you can't really use the 15min of ADI is ridiculous along with the engine model overall.

 

The DCS model is gonna be interesting to fly, I'm sure it will be more accurate in some areas due to it being developed over such a long period of time.

Edited by Legioneod

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2 hours ago, Legioneod said:

The DCS model is gonna be interesting to fly, I'm sure it will be more accurate in some areas due to it being developed over such a long period of time.

 

Haha you think they have actually been developing the P-47 all this time?

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On 10/10/2019 at 1:42 AM, Legioneod said:

We have the D-28 not D-25. D-25 had the Hamilton Prop and was slightly faster in level speed and climb iirc.

 

Plus the Hydromatic prop looks better IMHO.

Looks like the props could be changed. I wonder how much re-working was needed, though. The Curtiss was electric (hence the name), while the Hamilton was hydraulic (hence the name).

There needed to be an interface for each to make that interchange work...

 

+1 on the 150 octane fuel for the P-47.

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2 hours ago, Bremspropeller said:

 

Plus the Hydromatic prop looks better IMHO.

Looks like the props could be changed. I wonder how much re-working was needed, though. The Curtiss was electric (hence the name), while the Hamilton was hydraulic (hence the name).

There needed to be an interface for each to make that interchange work...

 

+1 on the 150 octane fuel for the P-47.

I don't know if the different named variants of the D-22/23, D-25/26 and D-27/28 could interchange between the electric and hydromatic props.

There are pictures of D-30/40s using both the Hamilton Hydromatic and Curtiss/A.O. Smith electric propellers, and this version had a different cockpit layout compared to the D-25 to D-28, so it is possible the wiring was re-arranged to allow easy interchangeability.

 

Also there were 3 wide bladed propellers, our P-47 has the 12'2" A.O Smith prop, instead of the 13" Curtis or Hamilton.

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9 hours ago, Bremspropeller said:

 

Plus the Hydromatic prop looks better IMHO.

Looks like the props could be changed. I wonder how much re-working was needed, though. The Curtiss was electric (hence the name), while the Hamilton was hydraulic (hence the name).

There needed to be an interface for each to make that interchange work...

 

+1 on the 150 octane fuel for the P-47.

I think Hamilton is a much better looking prop as well, it's also better performing iirc.

hydraulic and electric props couldn't be interchanged as far as I'm aware. (not easily anyways)

 

I wish they would have went with the D-27, it's exactly the same as the D-28, the only difference is the prop used and the radio compass for the D-28. D-27 used Hamilton and the D-28 used Curtis and A.O. Smith.

Another thing I'm curious about is why the Devs went with A.O. Smith instead of the Curtis Electric? I wonder what the performance difference is between the two props.

 

6 hours ago, =362nd_FS=RoflSeal said:

I don't know if the different named variants of the D-22/23, D-25/26 and D-27/28 could interchange between the electric and hydromatic props.

There are pictures of D-30/40s using both the Hamilton Hydromatic and Curtiss/A.O. Smith electric propellers, and this version had a different cockpit layout compared to the D-25 to D-28, so it is possible the wiring was re-arranged to allow easy interchangeability.

 

Also there were 3 wide bladed propellers, our P-47 has the 12'2" A.O Smith prop, instead of the 13" Curtis or Hamilton.

 

The difference block numbers in these lineups was mostly due to the different props used and the factory they were built at.

Farmingdale used the Hamilton prop from the D-22 until the D-27, they switched to the Curtis with the D-28. Evansville used the Curtis Electric until the end of the war iirc.

 

Farmingdale

P-47D-22 (Hamilton prop)

P-47D-25 (Hamilton prop)

P-47D-27 (Hamilton prop)

 

P-47D-28 (switched to Curtis Electric Paddle Blade.)

 

Evansville

P-47D-23 (C.E. Prop)

P-47D-26 (C.E. Prop)

P-47D-28 (C.E. Prop)

 

The D-22/23, D-25/26, were identical to each other. The D-27/28 were pretty much identical as well.

 

The easiest way to tell the difference between the props is to look at the Hubs. The Hamilton used a rounded Hub while the Curtis Electric and A.O. Smith used a more pointed Hub.

 

 

Hamilton Prop. notice the hub.

w-395-kik-crew.jpg

 

Curtis Electric.

w-395-p47-the-wolf.jpg

 

A.O. Smith

L3-Obest.jpg

 

 

 

I've heard that Curtis Electric had a asymmetrical paddle blade prop but not sure how true it is. I thought that only A.O. Smith was asymmetrical.

Looks like an A.O. Smith but has a Curtis electric logo. Haven't checked the serial number but that could lead to the answer.

4510.jpg

 

Not sure how true this is but I think he's confusing the A.O. Smith as a curtis prop.

lW3UnKK.png

Edited by Legioneod
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On 10/9/2019 at 8:39 AM, RedKestrel said:

The P-47D-28 we have in game matches the climb and top speed of the real thing very closely. From that I surmise that the engine output at the various power settings is accurate.

 

On 10/9/2019 at 6:42 PM, Legioneod said:

P-47 level speed performance is pretty close to real numbers.

 

I assume that many (most?) 1GCCFPs play this sim with the automatic engine boxes checked. I've been testing with Throttle auto limit and Engine auto control checked, but using manual radiator controls. I'm gradually getting to manual control for everything. Not being well versed with P-47, my initial take was the Clean (no external stores) performance numbers in game agreed with the published data.

 

Can you fellas test something? Simply as independent sets of eyeballs to see if I'm missing something obvious. I'm using the last page of a PDF covering the -25 through -35 (attached) as my reference source. The configuration calls for 2 x 165 gallon tanks (green box upper right corner). Carrying these would approximate carrying 2 x M65 1000 pound bombs. How so? 165 gallons of gas at 6 pounds per gallon equals 990 pounds. 

 

Empty weight for the airplane in the Specs is 10,483 pounds. Full fuel is 370 gallon x 6 pounds per gallon equals 2220 pounds (not 3095 pounds listed in the Specs) and 2 x M65s another ~2000 pounds or there about. So a full load and 2 bombs puts the weight around 14,700 pounds before takeoff. The chart shows allowable weights from 12,000 to 16,000 pounds so we've got that covered.

 

Right now I'm only looking at Column I in the lower left corner using Max Continuous thrust (2550 rpm, 42" MP and Auto Rich mixture) at Seal Level (S.L) and 5000', the two rows of data at the very bottom of the chart. With the auto features checked, I'm unable to get anything close to 270 mph with Max Continuous (2550 rpm and a bit more than 42" in game) at tree top height. I'm unable to get anything close to 288 mph at 5,000'. I have yet to test the power settings for 5,000' in Columns II (2550 rpm and 36") or Column III (~2250 rpm and ~34" it's blurry to me).

 

12824443_Performancepagemarkedup.thumb.jpg.32b963cafc418ce69c6dae0daaf69bc4.jpg

 

My general assessment is the drag coefficients are off by a large margin and guys hauling iron can not achieve anything close to the historical performance in terms of achievable speed while low level. 

 

So...what airspeed can you guys get at Max Continuous power while hauling 2 x M65s at 5,000' or at tree top height?

 

 

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40 minutes ago, busdriver said:

 

 

I assume that many (most?) 1GCCFPs play this sim with the automatic engine boxes checked. I've been testing with Throttle auto limit and Engine auto control checked, but using manual radiator controls. I'm gradually getting to manual control for everything. Not being well versed with P-47, my initial take was the Clean (no external stores) performance numbers in game agreed with the published data.

 

Can you fellas test something? Simply as independent sets of eyeballs to see if I'm missing something obvious. I'm using the last page of a PDF covering the -25 through -35 (attached) as my reference source. The configuration calls for 2 x 165 gallon tanks (green box upper right corner). Carrying these would approximate carrying 2 x M65 1000 pound bombs. How so? 165 gallons of gas at 6 pounds per gallon equals 990 pounds. 

 

Empty weight for the airplane in the Specs is 10,483 pounds. Full fuel is 370 gallon x 6 pounds per gallon equals 2220 pounds (not 3095 pounds listed in the Specs) and 2 x M65s another ~2000 pounds or there about. So a full load and 2 bombs puts the weight around 14,700 pounds before takeoff. The chart shows allowable weights from 12,000 to 16,000 pounds so we've got that covered.

 

Right now I'm only looking at Column I in the lower left corner using Max Continuous thrust (2550 rpm, 42" MP and Auto Rich mixture) at Seal Level (S.L) and 5000', the two rows of data at the very bottom of the chart. With the auto features checked, I'm unable to get anything close to 270 mph with Max Continuous (2550 rpm and a bit more than 42" in game) at tree top height. I'm unable to get anything close to 288 mph at 5,000'. I have yet to test the power settings for 5,000' in Columns II (2550 rpm and 36") or Column III (~2250 rpm and ~34" it's blurry to me).

 

12824443_Performancepagemarkedup.thumb.jpg.32b963cafc418ce69c6dae0daaf69bc4.jpg

 

My general assessment is the drag coefficients are off by a large margin and guys hauling iron can not achieve anything close to the historical performance in terms of achievable speed while low level. 

 

So...what airspeed can you guys get at Max Continuous power while hauling 2 x M65s at 5,000' or at tree top height?

 

 

I'll do some testing and post back. But I agree that in some cases the P-47 seems a bit too draggy.

 

EDIT: Just tested at sea level and I can't get anything over 257 at 42" 2550.

At 5k I got around 252 mph which is about 271 mph TAS. Seems like it's going around 15+ mph slower than it should. Are bombs draggier than drop tanks?

Edited by Legioneod

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6 hours ago, Legioneod said:

I'll do some testing and post back. But I agree that in some cases the P-47 seems a bit too draggy.

 

EDIT: Just tested at sea level and I can't get anything over 257 at 42" 2550.

At 5k I got around 252 mph which is about 271 mph TAS. Seems like it's going around 15+ mph slower than it should. Are bombs draggier than drop tanks?

They certainly could be. They have fins and other protrusions coming out of them that fuel tanks do not. Also, are you engaging the turbo at all?

 

in general I think that automating the engines in the difficulty settings costs you performance by a small margin.

 

Edited by RedKestrel

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1 hour ago, RedKestrel said:

They certainly could be. They have fins and other protrusions coming out of them that fuel tanks do not. Also, are you engaging the turbo at all?

 

in general I think that automating the engines in the difficulty settings costs you performance by a small margin.

 

I wasn't automating anything engine management was full real. Guess I should put auto management on so the test would be more comparable test to busdriver.

 I had to engage the turbo at 5k ft in order to get 42" of manifold. Sea level I didn't engage it due to not needing it, it wouldn't have given any real gains at that alt.

Edited by Legioneod

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On 10/9/2019 at 7:07 PM, Jade_Monkey said:

 

Haha you think they have actually been developing the P-47 all this time?

 

The model in DCS is supposed to be the D-30, I've been waiting for that since they first announced it.  I stopped buying DCS materials a long time ago because of they have not honored the WWII Backer Package.  The P-47 and Me-262 have not seen the light of day yet and I won't buy another package from them until they do.  But I'm looking forward to getting in their P-47 just to see how it flies and handles.  I do fly the Mustang and play the free missions you can find in the downloads section.  Since the P-38, P-51 and Tempest came out it does seem like the P47 wallows a bit with full bomb load and 60% Fuel.  The Lightning with four 1,000 or six 500lb bombs climbs like a bat out of hell in comparison.  The 150 octane option for the T-bolt might improve on that situation.

 

Hoss

Edited by 361st_Hoss
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15 minutes ago, Legioneod said:

I wasn't automating anything engine management was full real. Guess I should put auto management on so the test would be more comparable test to busdriver.

 I had to engage the turbo at 5k ft in order to get 42" of manifold. Sea level I didn't engage it due to not needing it, it wouldn't have given any real gains at that alt.

Maybe also try engaging the turbo at sea level a little. I think the combination of MP regulator and RPM governor may make it possible for the engine to not generate its max power while showing the same MP and RPMon instruments. They are interdependent, I veg never been fully clear on one affecting the other but I feel it’s like mixture settings. You can pull the same MP and RPM but if your mixture is too lean you still don’t generate full power because the governor and regulator compensate for it. 

 

Edit: I knew you weren’t using automation, sorry if I wasn’t clear. I just was mentioning the automation for others who do use it. I have seen a lot of people say that they can’t reach max performance since the limiters are very cautious with the engines.

Edited by RedKestrel

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15 minutes ago, 361st_Hoss said:

 

The model in DCS is supposed to be the D-30, I've been waiting for that since they first announced it.  I stopped buying DCS materials a long time ago because of they have not honored the WWII Backer Package.  The P-47 and Me-262 have not seen the light of day yet and I won't buy another package from them until they do.  But I'm looking forward to getting in their P-47 just to see how it flies and handles.  I do fly the Mustang and play the free missions you can find in the downloads section.  Since the P-38, P-51 and Tempest came out it does seem like the P47 wallows a bit with full bomb load and 60% Fuel.  The Lightning with four 1,000 or six 500lb bombs climbs like a bat out of hell in comparison.  The 150 octane option for the T-bolt might improve on that situation.

 

Hoss

150 Fuel would certainly give the P-47 a big boost. Currently in order to get max speeds (similar to charts) you have to take around 50% fuel irrc. With 150 fuel we'll get much higher speeds with full fuel loads and the ability to run 65" WEP without water injection.

 

This test was done on a Razorback but we should see similar numbers if we get 150 fuel for the D-28.

The test was conducted with a Combat load of Full internal fuel and wing racks.

It attained a top speed of 444mph in this configuration and if it went clean (no racks) it would have been around 448-450mph. With less fuel load it most likely would have went even faster.

Overall we'd get a pretty large performance increase from using 150 fuel.

http://www.wwiiaircraftperformance.org/p-47/p47-26167.html

 

12 minutes ago, RedKestrel said:

Maybe also try engaging the turbo at sea level a little. I think the combination of MP regulator and RPM governor may make it possible for the engine to not generate its max power while showing the same MP and RPMon instruments. They are interdependent, I veg never been fully clear on one affecting the other but I feel it’s like mixture settings. You can pull the same MP and RPM but if your mixture is too lean you still don’t generate full power because the governor and regulator compensate for it. 

Could be, I'll try it and get back to you, I know that having the turbo interlinked with throttle can decrease performance. Really we shouldn't need the turbo at sea level for anything below WEP. The engine supercharger is good till around 3,000ft.

Edited by Legioneod
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When I fly online I usually take a full ordnance load and around 60% fuel depending on how far the target is, but I take Requiem's advice and use WEP take off using the ADI.  And it gets airborne pretty quick, but climbs like a brick... LOL.

 

Cheers

Hoss

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Keep in mind this is with full combat load (full fuel, 300rpg, and wing racks)

We can't get these speeds in-game unless we fly with less fuel and no racks iirc.

 

150 would definitely be a large benefit to the P-47, especially when going lightweight.

p47d-44-1-level.jpg

 

Here's another comparison of the same aircraft between Mil power, and WEP both with and without water. (no 70" WEP in this comparison though)

As you could see this page has slightly higher speeds compared to the above test, could be due to different criteria, etc.

p47-eglin-level.jpg

Edited by Legioneod

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This definitely needs more attention. My time is limited for a few weeks but when I can Im going to do a series of tests along side historical data to see how the Jug really compares. Hopefully in the mean time 150 Fuel is taken into consideration ;)

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Yea i also hope they add 150 fuel.

Since if the P-51 gets it then the P-47 should too.

 

For the P-38 it could be argued that its historical for this Timeframe not to have 150 octane fuel as the only P-38s in the area at the time of Bodenplatte were part of the 9th airforce

and as such they were all based on the continent (and units on the continent did not have 150 octane fuel).

 

P-51 units located on the Continent (9th airforce) also did not have 150 octane but 8th airforce P-51s based in UK did,

this might be their logic for giving the P-51 150 Octane.

 

But if that is the case then the P-47 should also get 150 octane.

Since while the majority of the P-47 in the area at this time belonged to the 9th airforce there were still some P-47s in the 8th airforce

(56th fighter group)

they even saw action during the Battle of the bulge

(23rd of december P47s from the 56th FG engaged German fighters while escorting bombers supporting Allied ground forces),

and the P-47s operated by the 8th airforce did have 150 octane.

 

So in my opinion they should either give the P-47 150 octane (allowing it to simulate 8th airforce P-47s) or they should remove it from the P-51 (Having it Simulate a 9th Airforce P-51).

 

 

 

Edited by mattebubben

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On 10/9/2019 at 4:42 PM, Legioneod said:

Also the fact that you can't really use the 15min of ADI is ridiculous along with the engine model overall.

 

 

^

 

 

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8 hours ago, mattebubben said:

So in my opinion they should either give the P-47 150 octane (allowing it to simulate 8th airforce P-47s) or they should remove it from the P-51 (Having it Simulate a 9th Airforce P-51).

 

 

 

 Don't forget the Mk.IX

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2 hours ago, 361st_Hoss said:

 Don't forget the Mk.IX

Mk. IX has 150 fuel already.

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5 hours ago, 361st_Hoss said:

 Don't forget the Mk.IX

Well for the MK.IX its historical for 1945 Scenarios.

As historically units on the continent were supplied with 150 octane starting in Jan 1945.

Where as to my Knowledge no US units on the continent did.

 

But yes for any 1944 scenarios it should be limited to 100 octane.

(Unless simulating Spitfires stationed in the UK)

Edited by mattebubben

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On 10/9/2019 at 2:49 PM, BSS_Ripper* said:

The plane is not powerful and robust. It’s not normal that no rudder trim is necessary on takeoff at full power with very little rudder trim for the R2800 Powerplant! It’s a real joke! It feels anemic.

 

Have you set mix to the 100% when using the water injection? Otherwise the WEP will be weaker and I'm not sure if that's realistic.

 

Said that 15m of ADI should be usable at full boost in one go if needed. The workaround is to lower MP to 58-60" which is... workable if you are very careful but that should not be necessary.

 

On 10/13/2019 at 8:21 PM, Legioneod said:

150 Fuel would certainly give the P-47 a big boost. Currently in order to get max speeds (similar to charts) you have to take around 50% fuel irrc. With 150 fuel we'll get much higher speeds with full fuel loads and the ability to run 65" WEP without water injection.

 

Another benefit would be easier use of the plane - as now to get best of the P-47D (and not kill the engine in a short order) if you want WEP "alike" power it's convoluted: turn on ADI injection, change mix to 100%, set throttle (use turbo-throttle link) for 60", set RPM for 2600rpm and repeat inverse for WEP off.

 

So +1 for the 150 "mod" - if the current system has to stay then it would be relatively simple way for correct and accessible use of the 65" WEP at least.

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5 hours ago, Ehret said:

 

Have you set mix to the 100% when using the water injection? Otherwise the WEP will be weaker and I'm not sure if that's realistic.

 

Said that 15m of ADI should be usable at full boost in one go if needed. The workaround is to lower MP to 58-60" which is... workable if you are very careful but that should not be necessary.

The Full Rich mix should only be used when Auto rich fails. When you go full bang the mixture should follow suit. 

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@busdriver With the 2 bombs and 50% fuel which according to the in game specs is 15550 pounds of weight the plane does 262 mph at sea level with 42" at 2550 RPM. I don't know how much drag do the bombs have vs the drop tanks... but I would think the drop tanks are more aerodynamic. If you work with Kg and then finally convert it to pounds you get the correct weights. If you take full fuel and the two bombs the total weight is 16660 pounds.
 

On 10/13/2019 at 7:41 PM, Legioneod said:

Keep in mind this is with full combat load (full fuel, 300rpg, and wing racks)

We can't get these speeds in-game unless we fly with less fuel and no racks iirc

 


That P-47 test is done with a razorback D-22 model if you check the serial number. And afaik those had less total internal fuel. If you want to bring our P-47D-28 weight to 13230 lb you have to take 50% fuel. Without wing racks at 65" with water injection our P-47D-28 with 50% fuel, cowl shutters closed, 50% oil and 50% intercooler achieves 347 mph at sea level, and with wing racks it does 342 mph.

When the plane came out I made some test comparisons with that D-22 flight test and the info Gavrick shared giving 3 speed points at diferent altitudes for the real D-28 in the manual/technical specs, and put it together in a chart.

P-47D-28_clean_vs_P-47D-22__D-28_IRL.png

So appart from sea level speed it seems the razorbacks were more aerodynamic than the bubbletops, or at least the serial number 42-26167 plane. That engine at 65" is making less power than our D-28 engine at 65" because it is without water injection and with the 150 octane fuel, which gives a bit less power than the standard 130 octane fuel at the same manifold pressure (around 20-30 HP difference for what I could see in other engines such as the Griffon, Sabre and Merlin).

Edited by -=PHX=-SuperEtendard
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1 hour ago, -=PHX=-SuperEtendard said:

With the 2 bombs and 50% fuel which according to the in game specs is 15550 pounds of weight the plane does 262 mph at sea level with 42" at 2550 RPM. I don't know how much drag do the bombs have vs the drop tanks... but I would think the drop tanks are more aerodynamic. If you work with Kg and then finally convert it to pounds you get the correct weights. If you take full fuel and the two bombs the total weight is 16660 pounds.

Thanks for taking the time to test and share your results! :salute:

 

Just so we're on the same page. Full internal fuel for the P-47 is 370 gallons which is 1400 liters. 370 gallons weighs 1,048 kilos. Being an american pilot, working with gallons and pounds all day is my natural state. I'm at a loss to duplicate your "all up" calculated weights. If an empty airplane weighs 10,483 pounds, a full load (370 gallons) of gas weighs 2,312 pounds (at a more precise 6.25 pounds per gallon) and two 1000 pound bombs add 2,000 pounds. I get 10,483 + 2,312 + 2,000 = 14,795 pounds. Add 170 pounds for a WWII pilot gets me up to 14,965 pounds.

 

At 50% fuel (185 gallons x 6.25 pounds per gallon = 1,156 pounds) and 2 M65 bombs I get 10,483 + 1,156 + 2,000 + 170 = 13,809 pounds.

 

Using metric units, at "all up" I start with the empty airplane at 4,755 kilos, 1400 liters of gas weighs 1,048 kilos, bombs add 907 kilos, and the pilot another 77 kilos. My addition tells me that's only 6,787 kilos or 14,963 pounds. 

 

(without snark or sarcasm) What am I obviously missing? Meaning what have I left out of the equation? I'm getting OLD and frequently make mistakes. ;)

And for the record, the game Spec page showing 3095 pounds as the weight of full fuel is wrong. They used 8.3 pounds/gallon which is just a bit more than the weight of a gallon of water.

 

**********Changing gears***************

I'm running a series of tests, so my contribution is limited at the moment. Basically I will test four different ambient Sea Level temperatures (-18C, 0C, 15C, and 30C) with the altimeter 29.92" (1013 mm). I'm also assuming a standard adiabatic lapse rate for the temperature. IOW I'm saying the temperature decreases 2C for every thousand feet of altitude gain. So for my 5,000' runs I'm calculating an expected True airspeed based upon that lapse rate. The Devs may or may not do that.

 

My simple initial test on the Rhineland map was with 1210 liters (320 gallons assuming 50 gallons for start, taxi, takeoff climb to 5,000') with 2 x M65s. I used Max Continuous power/thrust (2550 & 42") and Column II (2350 & 36") with the outlet cooler doors closed. 

 

On the Rhineland map, at 5,000' and with Max Continuous (2,550 & 42") I only got 249 mph IAS but expected to see 259 mph IAS to match the Flight Manual data showing 288 mph TAS.  At tree top height I expected to see 260 IAS (271 TAS) but only got 252 IAS. I made Excel charts to fill in the missing IAS to CAS numbers from the FM, and used online E6B calculations to do the ICE-T problem (find TAS for a given IAS a various temperatures and 29.92" of pressure). 

 

That's just my initial result. The more I read about the P-47 and compare its performance data in manuals to that of the P-51 and P-38, the in game performance is NOT terribly surprising. I started my testing thinking something was terribly wrong in game. I was never a fan of the P-47, thought of it as a big drag magnet, but comparable in performance to the other two...the flight manuals clearly show I should not hold that opinion. I'll have a better informed opinion later this week.

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11 hours ago, -=PHX=-SuperEtendard said:

@busdriver With the 2 bombs and 50% fuel which according to the in game specs is 15550 pounds of weight the plane does 262 mph at sea level with 42" at 2550 RPM. I don't know how much drag do the bombs have vs the drop tanks... but I would think the drop tanks are more aerodynamic. If you work with Kg and then finally convert it to pounds you get the correct weights. If you take full fuel and the two bombs the total weight is 16660 pounds.
 


That P-47 test is done with a razorback D-22 model if you check the serial number. And afaik those had less total internal fuel. If you want to bring our P-47D-28 weight to 13230 lb you have to take 50% fuel. Without wing racks at 65" with water injection our P-47D-28 with 50% fuel, cowl shutters closed, 50% oil and 50% intercooler achieves 347 mph at sea level, and with wing racks it does 342 mph.

When the plane came out I made some test comparisons with that D-22 flight test and the info Gavrick shared giving 3 speed points at diferent altitudes for the real D-28 in the manual/technical specs, and put it together in a chart.

P-47D-28_clean_vs_P-47D-22__D-28_IRL.png

So appart from sea level speed it seems the razorbacks were more aerodynamic than the bubbletops, or at least the serial number 42-26167 plane. That engine at 65" is making less power than our D-28 engine at 65" because it is without water injection and with the 150 octane fuel, which gives a bit less power than the standard 130 octane fuel at the same manifold pressure (around 20-30 HP difference for what I could see in other engines such as the Griffon, Sabre and Merlin).

 

Thats D-22 in the test was made with full internal fuel of 305 gallons and wing racks. Only way to have a comparable test is to load the D-28 with the same load and compare.

The Design useful loads on the D-22 and D-28 were only 180 lbs difference from the documents I have.

 

Also, the fuel weighs about 6lbs per gallon, I'm wondering if the devs are using 8lbs for fuel if the specs state 3095 lbs as full fuel weight.

Full fuel load should only weigh about 2200lbs or so. If tank weight is included it should only be around 2654lbs.

 

From the testing I've done it seems the bubbletop is much draggier than the razorbacks, at least at lower power settings. The D-22 at 15K ft at 56" WEP is 395mph yet the D-28 at same WEP and weight can only get around 377mph. Thats an 18mph speed difference for the same WEP and Weight, pretty significant imo.

 

I'll need to do more testing but this are just some rough numbers I've come up with so far, I'm sure there are errors to be worked out.

 

EDIT: Another thing is the props used on the D-22 and D-28 are different. The D-22 has a Hamilton Standard prop and as a result has about 8-9 mph performance boost over the Curtis electric. In-game we don't have the curtis electric so I can't say the performance different between the curtis and in-game A.O. Smith.

 

 

 

 

8 hours ago, busdriver said:

 

That's just my initial result. The more I read about the P-47 and compare its performance data in manuals to that of the P-51 and P-38, the in game performance is NOT terribly surprising. I started my testing thinking something was terribly wrong in game. I was never a fan of the P-47, thought of it as a big drag magnet, but comparable in performance to the other two...the flight manuals clearly show I should not hold that opinion. I'll have a better informed opinion later this week.

 

Not sure what you mean? P-47 performance is comparable to the P-51 and P-38 but not at all altitudes, the P-47 is truly a high altitude fighter and really only sees it's potential when operating above 20,000ft.

In-game there are more contributing factors to the P-47s relatively poor performance than just the top speeds (which arent that far off when full WEP.

Edited by Legioneod

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17 hours ago, busdriver said:

Thanks for taking the time to test and share your results! :salute:

 

Just so we're on the same page. Full internal fuel for the P-47 is 370 gallons which is 1400 liters. 370 gallons weighs 1,048 kilos. Being an american pilot, working with gallons and pounds all day is my natural state. I'm at a loss to duplicate your "all up" calculated weights. If an empty airplane weighs 10,483 pounds, a full load (370 gallons) of gas weighs 2,312 pounds (at a more precise 6.25 pounds per gallon) and two 1000 pound bombs add 2,000 pounds. I get 10,483 + 2,312 + 2,000 = 14,795 pounds. Add 170 pounds for a WWII pilot gets me up to 14,965 pounds.

 

At 50% fuel (185 gallons x 6.25 pounds per gallon = 1,156 pounds) and 2 M65 bombs I get 10,483 + 1,156 + 2,000 + 170 = 13,809 pounds.

 

Using metric units, at "all up" I start with the empty airplane at 4,755 kilos, 1400 liters of gas weighs 1,048 kilos, bombs add 907 kilos, and the pilot another 77 kilos. My addition tells me that's only 6,787 kilos or 14,963 pounds. 

 

(without snark or sarcasm) What am I obviously missing? Meaning what have I left out of the equation? I'm getting OLD and frequently make mistakes. ;)

And for the record, the game Spec page showing 3095 pounds as the weight of full fuel is wrong. They used 8.3 pounds/gallon which is just a bit more than the weight of a gallon of water.

 


The loaded weight in game is calculated like this:

Empty weight: 4755 Kg (10483 lb)
 

Minimum weight (no ammo, 10% fuel, 4 MG removed): 5163.9 kg (11385 lb)

So from empty to minimum you would have the pilot and his gear, the oil, the water-methanol, 10% fuel (37 gallons), and 4 .50 cals.

Going from minimum weight to loaded weight is easier as what we have to add is specified in the stats:

90% fuel: 333 gallons = 905.4 Kg (1996 lb) they consider 1 US gallon of fuel weighting 5.994 pounds

The other four .50 cals = 130 Kg (286.6 lb), from the modifications specs.

The standard ammunition for all eight guns: 301.2 Kg (664 lb), from the modifications specs.

So if we add it all together: 11385 lb + 1996 lb + 286.6 lb + 664 lb = 14331 lb (6500 Kg) which is basically what's listed in the stats: "Standard weight: 6503 kg (14337 lb)"

 

 

9 hours ago, Legioneod said:

 

Thats D-22 in the test was made with full internal fuel of 305 gallons and wing racks. Only way to have a comparable test is to load the D-28 with the same load and compare.

The Design useful loads on the D-22 and D-28 were only 180 lbs difference from the documents I have.

 

Also, the fuel weighs about 6lbs per gallon, I'm wondering if the devs are using 8lbs for fuel if the specs state 3095 lbs as full fuel weight.

Full fuel load should only weigh about 2200lbs or so. If tank weight is included it should only be around 2654lbs.

 

From the testing I've done it seems the bubbletop is much draggier than the razorbacks, at least at lower power settings. The D-22 at 15K ft at 56" WEP is 395mph yet the D-28 at same WEP and weight can only get around 377mph. Thats an 18mph speed difference for the same WEP and Weight, pretty significant imo.

 

I'll need to do more testing but this are just some rough numbers I've come up with so far, I'm sure there are errors to be worked out.

 

EDIT: Another thing is the props used on the D-22 and D-28 are different. The D-22 has a Hamilton Standard prop and as a result has about 8-9 mph performance boost over the Curtis electric. In-game we don't have the curtis electric so I can't say the performance different between the curtis and in-game A.O. Smith.


Not sure what you mean? P-47 performance is comparable to the P-51 and P-38 but not at all altitudes, the P-47 is truly a high altitude fighter and really only sees it's potential when operating above 20,000ft.

In-game there are more contributing factors to the P-47s relatively poor performance than just the top speeds (which arent that far off when full WEP.


The D-28 has 370 gallons of internal fuel, that adds to the total weight beacause of the extra fuel tank and the 70 gallons of extra fuel, with both it looks like amounts for a difference of ~1100 pounds, as I posted above, the full internal fuel + standard ammo weight for the D-28 is 14331 lb, while the D-22 test weight is 13230 lb.
To have the same weight of the D-22 at 300 gallons of fuel, we have to take the D-28 with 185 gallons of fuel. I think it's because of the extra fuel tank, but I don't know what other differences there were in the airframes (counterweights, different water supply?, I don't know)

If I take the D-28 with the wing racks and 13230 lb of weight it is slower than the D-22 by a good margin:

unknown.png

This is almost 1 year old so there may be some changes with all the updates we had in between, I would have to test it again.

Edited by -=PHX=-SuperEtendard

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7 hours ago, -=PHX=-SuperEtendard said:


The loaded weight in game is calculated like this:

Empty weight: 4755 Kg (10483 lb)
 

Minimum weight (no ammo, 10% fuel, 4 MG removed): 5163.9 kg (11385 lb)

So from empty to minimum you would have the pilot and his gear, the oil, the water-methanol, 10% fuel (37 gallons), and 4 .50 cals.

Going from minimum weight to loaded weight is easier as what we have to add is specified in the stats:

90% fuel: 333 gallons = 905.4 Kg (1996 lb) they consider 1 US gallon of fuel weighting 5.994 pounds

The other four .50 cals = 130 Kg (286.6 lb), from the modifications specs.

The standard ammunition for all eight guns: 301.2 Kg (664 lb), from the modifications specs.

So if we add it all together: 11385 lb + 1996 lb + 286.6 lb + 664 lb = 14331 lb (6500 Kg) which is basically what's listed in the stats: "Standard weight: 6503 kg (14337 lb)"

 

 


The D-28 has 370 gallons of internal fuel, that adds to the total weight beacause of the extra fuel tank and the 70 gallons of extra fuel, with both it looks like amounts for a difference of ~1100 pounds, as I posted above, the full internal fuel + standard ammo weight for the D-28 is 14331 lb, while the D-22 test weight is 13230 lb.
To have the same weight of the D-22 at 300 gallons of fuel, we have to take the D-28 with 185 gallons of fuel. I think it's because of the extra fuel tank, but I don't know what other differences there were in the airframes (counterweights, different water supply?, I don't know)

If I take the D-28 with the wing racks and 13230 lb of weight it is slower than the D-22 by a good margin:

 

Empty Weight of the D-22 is 10,143 lbs, empty weight of the D-28 is 10,116 lbs. As you can see the weight is nearly identical between the two.

 

The design useful load of both aircraft is nearly identical as well and is what the devs used to get top speed performance.

In order to do a proper test you need to set up the D-28 in the same way as the D-22 in the test.

 

P-47 D-28 loadout

300 gallons of fuel (1135 liters)

Standard gun loadout

Wing Racks

 

Run the test with this loadout and you will have similar weights to the D-22.

 

Also I'm not debating the D-22 performance compared to the D-28, I know the D-22 is faster by a good margin. I was just curious how much drag the bubbletop causes.

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45 minutes ago, Legioneod said:

 

Empty Weight of the D-22 is 10,143 lbs, empty weight of the D-28 is 10,116 lbs. As you can see the weight is nearly identical between the two.

 

The design useful load of both aircraft is nearly identical as well and is what the devs used to get top speed performance.

In order to do a proper test you need to set up the D-28 in the same way as the D-22 in the test.

 

P-47 D-28 loadout

300 gallons of fuel (1135 liters)

Standard gun loadout

Wing Racks

 

Run the test with this loadout and you will have similar weights to the D-22.

 

Also I'm not debating the D-22 performance compared to the D-28, I know the D-22 is faster by a good margin. I was just curious how much drag the bubbletop causes.


At least in game the empty weight of the D-28 is listed as 10483 lb, with standard gun loadout, 300 gallons of fuel and wing racks it would end up at 13,977 lb according to the in game specs, some 750 lb heavier than the D-22 test. If there is some error in the weight of the plane it should be reported.

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1 minute ago, -=PHX=-SuperEtendard said:


At least in game the empty weight of the D-28 is listed as 10483 lb, with standard gun loadout, 300 gallons of fuel and wing racks it would end up at 13,977 lb according to the in game specs, some 750 lb heavier than the D-22 test. If there is some error in the weight of the plane it should be reported.

 

There is some error it seems. From this document the D-28 has an empty weight of 10,116 lbs.

1003216749_D-28usefullload.thumb.PNG.3bb48734cb2f31c6ad9c72aad766a077.PNG

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2 hours ago, Legioneod said:

 

There is some error it seems. From this document the D-28 has an empty weight of 10,116 lbs.


The empty weights are different yep, but looks like the in game empty weight isn't truly empty, some components are included. If I take the in game "minimum weight" which has 4 guns, 37 gallons of fuel, oil, water, pilot, etc included and add the rest of the components to match the configuration in the document you linked (rest of the fuel for a total of 206.5 gallons, an extra pair of guns and the ammo for the six of them), but using the in game weights, they end up very similar:

With 6 guns and ammo, 206.5 gallons of fuel the document lists the plane as 12958 lb of weight. With the in game specs that same configuration weights 13042 lb, a difference of 85 pounds.

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So the current P-47 does use the 135 octane fuel, not 100 octane. At 100 Octane it is limited to 54" with water injection, while we're looking at 64" with WI. 

 

Also 150 does not allow 64" without ADI. The P-47N-5 manual, at 150 octane required aircraft notes that the WI system automatically turns on once the throttle goes past 52".

 

As near as I can tell, the only advantage that using 150 octane would give you, baring the ability to modify the boost limiter, would be longer and higher safe power settings after the expenditure of the ADI.

 

The fundamental problem the P-47D-28 has right now, is the inability to safely run the engine at 64", not the availability of 150 octane. That is a limitation of the game's global engine modeling and needs to be addressed. 

 

Honestly I think the whole gas availability would add an interesting dimension to things. As I understand it, the P-51's Merlin was configured to run on 100 octane, but ended up getting 135 for a lot of times, same with the 54" P-47, but the Russian Lend Lease planes, as I understand it generally got 100 octane or less. But right now we don't have a sophisticated enough engine model to support or even consider that. 

 

Addendum: I don't recall the reference anymore but I suspect the P-38 never got re-rated for 150 octane for the same reason it never got four blades propellors, the aircraft was already into compressibility effects with its current power output so adding more power just made it easier for pilots to get the plane into trouble. The P-47M, by contrast took 150 octane and an extra large turbo to get there. I also wonder if there were logistical challenges to getting 150 out into the Pacific, where P-38's were critical. 

 

Edited by Voyager

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9 hours ago, Voyager said:

So the current P-47 does use the 135 octane fuel, not 100 octane. At 100 Octane it is limited to 54" with water injection, while we're looking at 64" with WI. 

 

Also 150 does not allow 64" without ADI. The P-47N-5 manual, at 150 octane required aircraft notes that the WI system automatically turns on once the throttle goes past 52".

 

As near as I can tell, the only advantage that using 150 octane would give you, baring the ability to modify the boost limiter, would be longer and higher safe power settings after the expenditure of the ADI.

 

The fundamental problem the P-47D-28 has right now, is the inability to safely run the engine at 64", not the availability of 150 octane. That is a limitation of the game's global engine modeling and needs to be addressed. 

 

Honestly I think the whole gas availability would add an interesting dimension to things. As I understand it, the P-51's Merlin was configured to run on 100 octane, but ended up getting 135 for a lot of times, same with the 54" P-47, but the Russian Lend Lease planes, as I understand it generally got 100 octane or less. But right now we don't have a sophisticated enough engine model to support or even consider that. 

 

Addendum: I don't recall the reference anymore but I suspect the P-38 never got re-rated for 150 octane for the same reason it never got four blades propellors, the aircraft was already into compressibility effects with its current power output so adding more power just made it easier for pilots to get the plane into trouble. The P-47M, by contrast took 150 octane and an extra large turbo to get there. I also wonder if there were logistical challenges to getting 150 out into the Pacific, where P-38's were critical. 

 

 

Yes 150 does indeed allow 64" without ADI, you can read the test report. P-47N used a new C series engine and had a different system than the D blocks. (Also the N had a different throttle mechanism that required an automatic ADI, later on a new throttle was fitted that allowed manual ADI iirc)

 

150 fuel would have the added benefit of running 2800hp at 70" instead of the current 2600hp at 64", and the ability to run 64" with ADI either on or off.

Another thing people aren't considering is that we'd be able to take higher fuel loads for the same performance as we have now, instead of only being able to take 205 gallons.

 

Overall the performance would be significantly improved when taking 205 (55%) fuel loads and would be about the same as current when taking higher loads.

With 150 fuel at 55% load we should see top speeds at critical altitude (24k) of around 445 - 450 mph and around 7+mph increase at most altitudes.

 

Still disappointed that the chose the D-28, I wish they would have chosen the D-27 due to it's much better performance with standard fuels and 64".

 

Basically with 150 fuel the D-28 performance will be similar (not exact) to a P-47M up to 24k ft, after that the M would be faster.

Edited by Legioneod

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On 10/19/2019 at 11:05 PM, busdriver said:

Thanks for taking the time to test and share your results! :salute:

 

Just so we're on the same page. Full internal fuel for the P-47 is 370 gallons which is 1400 liters.

 

370 US gallons equal 1400litres but 370 imperial gallons equal  1682 litres.

 

:) 

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4 minutes ago, DD_Arthur said:

 

370 US gallons equal 1400litres but 370 imperial gallons equal  1682 litres.

 

:) 

Yes but US gallons are what is used not imperial.🙂

Max fuel is 370 US gallons or 1400 litres.

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