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Getting the Jug up to speed.

Rakkis

By Rakkis
in DCS: P-47 Thunderbolt

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Rakkis

Rakkis

Posted
Posted

I saw a thread before Christmas either here or on Hoggit (I think... There's been some eggnog amongst others over the holiday) responding to folks having issues getting the P-47 above 200-250 kts. I am one of these people. Does anyone have a link to this write up that currently exists only in my imagination OR any tips/tricks/"Rakkis you moron this is what your doing wrong" comments? All assistance is greatly appreciated, thanks in advance. 

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grafspee

grafspee

Posted
Posted (edited)

Couple things impact top speed,

Gear up

flaps up

magnetos both on

mixture Auto rich

prop max

throttle max

boost lever as required to obtain max allowable MAP 52' w/o water 64' with water.

trim plane for minimum slip

as above close cowl flaps above 225mph

you should be able to go good above 320mph at SL, 350mph with water


Edited by grafspee
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System specs: I7 14700KF, Gigabyte Z790 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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Tiger-II

Tiger-II

Posted
Posted (edited)

DCS has a chronic problem of too much drag/aircraft unable to achieve their stated level-flight performance.

 

Things get even worse in a turn (AoA induced drag is too high).

 

They are starting to address it (A-10C II notably), but it's still far from where it should be.

 

If you want to see if the P-47 is affected, shut down the engine, feather the prop, close all flaps, and see how far she glides. Check against charts.

 

Fly accurately, and at the correct glide speed for the weight!


Edited by Tiger-II

Motorola 68000 | 1 Mb | Debug port

"When performing a forced landing, fly the aircraft as far into the crash as possible." - Bob Hoover.

The JF-17 is not better than the F-16; it's different. It's how you fly that counts.

"An average aircraft with a skilled pilot, will out-perform the superior aircraft with an average pilot."

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Tiger-II

Tiger-II

Posted
Posted (edited)
On 1/20/2021 at 5:33 PM, GUMAR said:

What charts? Can you share them?

 

 

Seems there isn't a defined glide speed for the P-47. All I can find is "maintain speed well above the stall". I guess they didn't bother much with the finer points of gliding back then???

 

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


Edited by Tiger-II

Motorola 68000 | 1 Mb | Debug port

"When performing a forced landing, fly the aircraft as far into the crash as possible." - Bob Hoover.

The JF-17 is not better than the F-16; it's different. It's how you fly that counts.

"An average aircraft with a skilled pilot, will out-perform the superior aircraft with an average pilot."

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303_Kermit

303_Kermit

Posted
Posted
On 1/22/2021 at 2:56 AM, Tiger-II said:

 

Seems there isn't a defined glide speed for the P-47. All I can find is "maintain speed well above the stall". I guess they didn't bother much with the finer points of gliding back then???

 

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

 

There's no point in gliding on an anvil 🙂.

 

It's enough to calculate Wing Surface to Waight ratio:
 

If you take empty P47 it's about 162kg/ m², just to compare ... for He 111 these ratio (calculated same way) is ...99kg/m², and for Bf-109 about 140kg/m²

 

Speed, and agility of P 47 in DCS makes me wonder. I dived yesterday on P47 that was dirclty below me (Storm of War server). with 680kph IAS i dived ... leveled off behind his tail, my speed drops down... 600...580...550....510IAS. P47 was impossible to catch. The Chart below shows that P47 D10 was able to keep 535 kph TAS asuming temperature about 32°C it gives routhly calculated 480IAS... 30 kph slower than i was doing in Bf109. 

below is the performance chart from: 
http://www.wwiiaircraftperformance.org/p-47/p-47.html
 

High speed: Intercooler and oil cooler flap neutral, cowl flaps closed; flaps and gear up; 2700 R.P.M. with water injection.

 

 
  Altitude
Ft. 		Manifold
Pressure
"Hg. 		Torque
Brake
Horsepower 		Turbo
RPM 		Exhaust
Back Press.
"Hg. 		Carb. Air
Temp.
°C 		True
Speed
MPH
 
           0 56   2210   7,200 36.0 32.0 333
    5,000 56   2265   9,400 33.2 27.0 353
  10,000 56   2315 11,600 31.4 23.0 372
  15,000 56   2335 13,850 30.3 23.0 390
  20,000 56   2325 16,200 30.5 26.0 406
  25,000 56   2265 18,650 32.5 33.0 421
  30,000 56   2225 21,400 35.7 43.0 433
  31,000 56   2220 22,000 36.5 46.0 435
  33,000 50.5 2020 22,000 32.0 39.0 430
  35,000 45.8 1740 22,000 30.0 32.0 422
  38,000 39.0 1550 22,000 25.3 23.0 404
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grafspee

grafspee

Posted
Posted (edited)

Our can do 64" not 56" it will be faster then those charts. Anyway it is fresh bird so it need some refining for sure.


Edited by grafspee

System specs: I7 14700KF, Gigabyte Z790 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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thrustvector

thrustvector

Posted
Posted

mmm, just trying her out, but im having same prob, i fly the spit/p51 etc so have a good idea on ww2 birds, but it just like missfires all the way, wont go over the 200/250 speed.

flaps/gear up, cowl down,mags on/ etc but just jitters all the way, even done all the training which was no diff than i have done? ideas?

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Diesel_Thunder

Diesel_Thunder

Posted
Posted

Make sure your landing light is not extended (lower left switch panel), that can cause the "flutter" as well.

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Art-J

Art-J

Posted
Posted
13 hours ago, thrustvector said:

mmm, just trying her out, but im having same prob, i fly the spit/p51 etc so have a good idea on ww2 birds, but it just like missfires all the way, wont go over the 200/250 speed.

flaps/gear up, cowl down,mags on/ etc but just jitters all the way, even done all the training which was no diff than i have done? ideas?

 

Primer pump locked?

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303_Kermit

303_Kermit

Posted
Posted
On 2/4/2021 at 7:06 PM, grafspee said:

Our can do 64" not 56" it will be faster then those charts. Anyway it is fresh bird so it need some refining for sure.

 

 

how much B.H.P. does exactly has "our" P47? the one in test has 2.335 B.H.P. on 15.000ft. is our more powerfull?

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grafspee

grafspee

Posted
Posted (edited)

64" definitely gives more power then 56' how much exactly i don't know.

Another thing p-47 D-10 isn't it razorback ?? razorback will be faster then bauble canopy.

D-25 is first one with bauble canopy. So it will be harder to compare, I know that wings get some changes down the road so D-10 is quite difrent.


Edited by grafspee

System specs: I7 14700KF, Gigabyte Z790 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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303_Kermit

303_Kermit

Posted
Posted

I don't want to sound like a "smart ass" ... but it's known that the greater the speeds are, the bigger thrust/power needed. If we check it with example of Bf-109 F2 / F4 / K4:

F2 - 1.159 B.H.P - 615 km/h (382 mph) at ????
F4 - 1.350 B.H.P - 659 km/h (410 mph) at 6,200 m (20,341 ft)
K4 - 1.850 B.H.P - 710 km/h (440 mph) at 7,500 m (24,600 ft)

 

-from F2 to F4 there's about 200ps more and as result 40kph more,

-form F4 to K4 there's 500B.H.P more but instead of expected 85kph more there's "only" 50kph more. We're reaching the limits of propeller driven aircraft. Further development of power will have bigger influence on better climb and acceleration than a  higher top speed. Good example of such effect is Spitfire XIV

With my best regards
303_Kermit

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grafspee

grafspee

Posted
Posted (edited)
55 minutes ago, 303_Kermit said:

I don't want to sound like a "smart ass" ... but it's known that the greater the speeds are, the bigger thrust/power needed. If we check it with example of Bf-109 F2 / F4 / K4:

F2 - 1.159 B.H.P - 615 km/h (382 mph) at ????
F4 - 1.350 B.H.P - 659 km/h (410 mph) at 6,200 m (20,341 ft)
K4 - 1.850 B.H.P - 710 km/h (440 mph) at 7,500 m (24,600 ft)

 

-from F2 to F4 there's about 200ps more and as result 40kph more,

-form F4 to K4 there's 500B.H.P more but instead of expected 85kph more there's "only" 50kph more. We're reaching the limits of propeller driven aircraft. Further development of power will have bigger influence on better climb and acceleration than a  higher top speed. Good example of such effect is Spitfire XIV

With my best regards
303_Kermit

710kph is no near limit of propeller driven aircrafts.

 

I can get DCS P-47 in to 350mph at SL with water.

If you climb with water injection P-47 makes impressive numbers.

So i don't know what is your problem here.

No you will not out climb K-4, 1850hp with that weigh is hard to beat. 

Only spitfire can compete in with tat climb rates.


Edited by grafspee

System specs: I7 14700KF, Gigabyte Z790 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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303_Kermit

303_Kermit

Posted
Posted

Its not the number what creates a problem, but it's the air density. With growing Ma number, you're beginning to reach so called "sound barrier". Some shapes are better suited to break, or came close to it , the others - are worse. 
P47 isn't actually a kind of very "slick" construction. Theoretically you can exceed sound barrier with propeller driven aircraft. That's of course when the propeller and plane are right.

For example with the propeller like these: https://en.wikipedia.org/wiki/Propfan

it's constructed to work with the flow (flow around the blades, not necessary around the plane) over Ma = 1. 

 

I'd like to talk about facts, not make any opinions. In the end opinions shall be irrelevant. Facts are (at least to me) important. I am pretty sure that there are somewhere some data about P47D25 ? Greater power gave surely greater speed - I'd really like to know for sure by how much mph. 

 

I heard also, that later in '44 Hub Zemke's squad become improved propeller that tuned up acceleration and climb. I'd like also to see the numbers, and / if it's implemented to DCS. 

 

I don't see a point in arguing. Opinions are irrelevant, what's relevant are facts. If you say that P-47D25 had stronger, more powerfull engine, than the data I gave are incorrect. I'll check.

With my best regards
303_Kermit

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grafspee

grafspee

Posted
Posted (edited)

Top speed ever done by prop driven plane was made by spitfire. 0.95mach it was in a dive.I doubt that you can pass 1 mach with prop too much drag.

QdSTg4P.png


Edited by grafspee

System specs: I7 14700KF, Gigabyte Z790 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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DSR_T-800

DSR_T-800

Posted
Posted
On 2/3/2021 at 7:18 PM, 303_Kermit said:

There's no point in gliding on an anvil 🙂.

 

It's enough to calculate Wing Surface to Waight ratio:
 

If you take empty P47 it's about 162kg/ m², just to compare ... for He 111 these ratio (calculated same way) is ...99kg/m², and for Bf-109 about 140kg/m²

 

Speed, and agility of P 47 in DCS makes me wonder. I dived yesterday on P47 that was dirclty below me (Storm of War server). with 680kph IAS i dived ... leveled off behind his tail, my speed drops down... 600...580...550....510IAS. P47 was impossible to catch. The Chart below shows that P47 D10 was able to keep 535 kph TAS asuming temperature about 32°C it gives routhly calculated 480IAS... 30 kph slower than i was doing in Bf109. 

below is the performance chart from: 
http://www.wwiiaircraftperformance.org/p-47/p-47.html
 

High speed: Intercooler and oil cooler flap neutral, cowl flaps closed; flaps and gear up; 2700 R.P.M. with water injection.

 

 
  Altitude
Ft. 		Manifold
Pressure
Hg. 		Torque
Brake
Horsepower 		Turbo
RPM 		Exhaust
Back Press.
"Hg. 		Carb. Air
Temp.
°C 		True
Speed
MPH
 
           0 56   2210   7,200 36.0 32.0 333
    5,000 56   2265   9,400 33.2 27.0 353
  10,000 56   2315 11,600 31.4 23.0 372
  15,000 56   2335 13,850 30.3 23.0 390
  20,000 56   2325 16,200 30.5 26.0 406
  25,000 56   2265 18,650 32.5 33.0 421
  30,000 56   2225 21,400 35.7 43.0 433
  31,000 56   2220 22,000 36.5 46.0 435
  33,000 50.5 2020 22,000 32.0 39.0 430
  35,000 45.8 1740 22,000 30.0 32.0 422
  38,000 39.0 1550 22,000 25.3 23.0 404


Did you try to out dive a P-47? 

http://i.imgur.com/LYvIQFB.gifv
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grafspee

grafspee

Posted
Posted (edited)

Small tip. Sound speed depends on air temp not density.

Storm of war server often uses early scenario so no mw50 for german planes. It will cut their top speed by a chunk 


Edited by grafspee

System specs: I7 14700KF, Gigabyte Z790 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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