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What's your top speed on P-47 at about 5000 ft?


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Wasn't able to go above ~312 mph on P-47 at about 5000 ft. I had WEP on, Throttle, RPM, Turbocharger, Mixture all to the maximum, outlet cowls shut, inlet cowls and oil rad are at about 50%. Do you think Thunderbolt should have reached higher speed?

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1 hour ago, Arthur-A said:

Wasn't able to go above ~312 mph on P-47 at about 5000 ft. I had WEP on, Throttle, RPM, Turbocharger, Mixture all to the maximum, outlet cowls shut, inlet cowls and oil rad are at about 50%. Do you think Thunderbolt should have reached higher speed?

Should be faster than that. 312 IAS is only around 342 TAS. You should be able to go around 360-370 TAS from what I've read in the manuals.

 

I'm gonna end up doing a bunch of test and see how it compares to RL. I don't expect it to be 100% accurate but I think it might be close.

Edited by Legioneod
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53 minutes ago, LeLv76_Erkki said:

At 5000 ft you can fully close both outlet cowls and oil radiator(fully closed is not true fully closed, there is still some air flowing through). Keep mixture at auto. Inlet cowl(= intercooler) at 50 %. Engage boost for water injection and 65" Hg manifold pressure.

I've found that on combat mode (100% throttle and pitch, no boost), you'll run faster with auto-rich mixture (85% mixture). On boosted mode you'll gain 5kph-8kph top speed when going 100% mixture (full rich afaik). Also you can fully close oil rads (it adds like 8kph indicated)

 

1 hour ago, Arthur-A said:

Wasn't able to go above ~312 mph on P-47 at about 5000 ft.

At 1000m alt (roughly 3000ft), I got to go 551kph indicated (344 mph)

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6 hours ago, Arthur-A said:

Wasn't able to go above ~312 mph on P-47 at about 5000 ft. I had WEP on, Throttle, RPM, Turbocharger, Mixture all to the maximum, outlet cowls shut, inlet cowls and oil rad are at about 50%. Do you think Thunderbolt should have reached higher speed?

 

at 5000ft i got 539kmh indicated ( 335mph) with trottle at 100%, rpm at 100%, mix at 100%, turbo at 100%, boost on, outlet both rads at 0%, inlet at 54%, could not go faster then that. Tryed to go manual rpm abow limit but thats only effective at high alts no gain on low alt. (Turn on hud on when testing so you can see exact speed from there)

Edited by 77.CountZero
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One thing I find odd is the fact that I need the turbo full forward to attain full WEP at sea level, from what I've read in the manual this shouldn't be the case. I should be able to reach full power without the turbo until reaching higher altitudes.

Does the game model it correctly? Seems wrong based off what I've read.

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I was also wondering why having the Turbo forward at lower altitudes doesn't completely overboost the engine. I understood you only start using it as you climb up higher, and that there wasnt any protection against breaking your engine if you don't pay attention to the MAP during dives.

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I get ~344 mph on the HUD in afirst try. You have to set the right settings initially and let it acellerate and that's the speed it reaches before things "get hot".

 

Important is:

 

- mixture rich (not leaned)

- water injection / boost enabled (higher MAP will be restricted otherwise)

- cowl flaps closed

- intercooler "Neutral"

- oil cooler "Neutral"

- 2700 rpm

 

And it will go fast. You will require significant turbo boost to reach max. MAP.

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2 minutes ago, ZachariasX said:

And it will go fast. You will require significant turbo boost to reach max. MAP.

Realistically you shouldn't even need the turbo to get Max WEP (from what I've read) at 5000ft.

Its one thing that doesn't make sense to me.

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2 minutes ago, Legioneod said:

Realistically you shouldn't even need the turbo to get Max WEP (from what I've read) at 5000ft.

Its one thing that doesn't make sense to me.

Yes, critical altitude of the supercharger is AFAIR about 1200 m. And it should provide max. boost. I also had expected little turbo use. I need to spend some more time to see what is going on there,

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30 minutes ago, ZachariasX said:

Yes, critical altitude of the supercharger is AFAIR about 1200 m.

Afaik, that's critical altitude for combat power, not WEP. Atleast that's the explanation i've received.

 

Atleast it's currently not considered a bug, that you need the turbocharger for achieving WEP at sea-level.

 

Of course if there's data avaliable that says otherwise, it should be corrected.

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10 minutes ago, Sgt_Joch said:

from what I have seen so far, the numbers pretty much match the test data:

 

http://www.wwiiaircraftperformance.org/p-47/P-47D_43-75035_Eng-47-1652-A.pdf

 

even though it is at 100%, the turbo is just loafing at low altitudes.

 

it is a bit early to cry bug, someone should check the pilot manual.

Problem is those test weren't with the D-28, or any bubbletop for that matter, it used a different engine and prop and had lower allowed engine settings than what we have.

 

 

Edited by Legioneod
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6 minutes ago, Legioneod said:

Problem is those test weren't with the D-28, or any bubbletop for that matter, it used a different engine and prop and had lower allowed engine settings than what we have.

 

 

 

I was only talking about the turbo RPM, the update only came out yesterday. If you think there is a bug, present your documentation.

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Question about the turbo control.  It seems you can just set it to max rpm, using T+= on keyboard, with tooltip saying 99% (mine never goes to 100%) and never have to bother with it for the rest of your flight.  Also I have never seen the turbo rpm get to 22,000 under any circumstance.  Is this correct?

 

Oh, I see posts talking about setting the intercooler and oil cooler shutters to "Neutral".  How do you know what the neutral position is?  The technochat never reports any such setting.

Edited by BlitzPig_EL
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9 minutes ago, BlitzPig_EL said:

Question about the turbo control.  It seems you can just set it to max rpm, using T+= on keyboard, with tooltip saying 99% (mine never goes to 100%) and never have to bother with it for the rest of your flight.  Also I have never seen the turbo rpm get to 22,000 under any circumstance.  Is this correct?

 

Oh, I see posts talking about setting the intercooler and oil cooler shutters to "Neutral".  How do you know what the neutral position is?  The technochat never reports any such setting.

The levers in the cockpit have a neutral label.

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9 minutes ago, BlitzPig_EL said:

Question about the turbo control.  It seems you can just set it to max rpm, using T+= on keyboard, with tooltip saying 99% (mine never goes to 100%) and never have to bother with it for the rest of your flight.  Also I have never seen the turbo rpm get to 22,000 under any circumstance.  Is this correct?

 

Oh, I see posts talking about setting the intercooler and oil cooler shutters to "Neutral".  How do you know what the neutral position is?  The technochat never reports any such setting.

Depends on the altitude, my turbo as gone to around 25k rpm at around 29-30k ft.

 

50% is neutral.

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6 minutes ago, BlitzPig_EL said:

Question about the turbo control.  It seems you can just set it to max rpm, using T+= on keyboard, with tooltip saying 99% (mine never goes to 100%) and never have to bother with it for the rest of your flight.  Also I have never seen the turbo rpm get to 22,000 under any circumstance.  Is this correct?

 

Oh, I see posts talking about setting the intercooler and oil cooler shutters to "Neutral".  How do you know what the neutral position is?  The technochat never reports any such setting.

 

the turbo only gets to 22000 RPM or more above 7,000-8,000 meters or so, at which point you have reduce the turbo to keep from overspeeding.

 

"neutral" is around 50%, if you look to the left of the cockpit, you will see the settings for the "intercooler" and "oïl cooler".

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I was of an understanding that the engine supercharger was built to provide around 50"-54" of boost at sea level, and that the 64"-74"+ of later war planes was effectively 'overboosting' that was permissible because the ADI kept detonation from occurring at those boost pressures. 

 

The intercooler should be controlling the intake manifold temperature, so once it's below the safe levels, you're ok and don't need any more, but it shouldn't hurt. 

 

Greg's Airplanes and Automobiles on YouTube has several aircraft water injection and P-47 design videos that go in to detail about it for the gearheads

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10 minutes ago, Voyager said:

I was of an understanding that the engine supercharger was built to provide around 50"-54" of boost at sea level, and that the 64"-74"+ of later war planes was effectively 'overboosting' that was permissible because the ADI kept detonation from occurring at those boost pressures. 

 

Has more to do with the fuel type used than with water. With 100 grade fuel you needed water to boost the engine to 65" but with 150 fuel water wasn't needed until 70"

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9 hours ago, Arthur-A said:

Wasn't able to go above ~312 mph on P-47 at about 5000 ft. I had WEP on, Throttle, RPM, Turbocharger, Mixture all to the maximum, outlet cowls shut, inlet cowls and oil rad are at about 50%. Do you think Thunderbolt should have reached higher speed?

2 hours ago, 77.CountZero said:

 

at 5000ft i got 539kmh indicated ( 335mph) with trottle at 100%, rpm at 100%, mix at 100%, turbo at 100%, boost on, outlet both rads at 0%, inlet at 54%, could not go faster then that. Tryed to go manual rpm abow limit but thats only effective at high alts no gain on low alt. (Turn on hud on when testing so you can see exact speed from there)

 

i run more tests and get 554kmh (344mph) at 5000ft with all same as before but prop rpm at 90%, it looks like in strait flying low you get big boost if yoou have that at 90 insted 100%, thats.

Also was doing on deck 572kmh with 90% prop rpm.

 

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8 minutes ago, 77.CountZero said:

 

i run more tests and get 554kmh (344mph) at 5000ft with all same as before but prop rpm at 90%, it looks like in strait flying low you get big boost if yoou have that at 90 insted 100%, thats.

Also was doing on deck 572kmh with 90% prop rpm.

 

 

Yeh but notice that you again lose from the 5 min timer, because manifold pressure will be high, 67" or so... When I use full everything and 2600 RPM I get timer warning only 3 minutes into boosted mode. :( 

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11 minutes ago, 77.CountZero said:

didnt notice that, thouse pesky timers :) 

 

But hey! What actually does work is lowering RPM when using 15 min power! At 300 m The difference between 2550 RPM and full 2700 RPM is 8 miles - 313 mph to 321 mph. This is significant because that means faster than 109 G-6 and G-4 instead of slower at the deck.

 

100 % throttle, 100 % turbo, 2550 RPM, 50 % inlet, 0 % outlet, 0 % oil. I only got timer warning at 22 minutes and 45 seconds (!!!)

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1 hour ago, LeLv76_Erkki said:

50 % inlet, 0 % outlet, 0 % oil.

On „Neutral“, the coolers produce least drag. As opposed to fully closed.

Edit: the „outlet“, the cowl flaps, they in turn should be cloed for least drag.

Edited by ZachariasX
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I got 345 mph at 65" WEP sea level, 50% fuel, no ammo. 100% turbo-throttle-RPM, outlet cowls closed, oil and intercooler cowls at "neutral".

 

345 mph is actually 5 mph faster than the equivalent test result I posted above.

Edited by Sgt_Joch
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so I just checked the january 1943 edition of the P47 pilot manual and I see no restrictions on the use of the turbocharger at low altitudes. It says it can be used at 100% (which is called "FULL ON") from take off, to climbing to normal flight. The only restrictions is not to exceed the max RPM.

 

the only restriction is not to use the turbocharger below 12,000 feet in auto-lean and low propeller RPM for best fuel economy.

Edited by Sgt_Joch
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Just a heads up: P-47 seems to be at its fastest for level flight when using 2550 RPM at least below the critical alt of 7000 m ish. Going to 2600 loses you 1-2 miles already. Hold the needle where the green marker on the RPM gauge ends. 87-89 % RPM.

 

281 mph IAS at 6000 m using this "20 min power", 309 mph using water. Thats as fast as 190 A-5 with closed gills, and you can do it for 2 min longer. And over 25 to 30 km/h faster than 109 G-2, G-4, G-14 and La-5FN!

9 minutes ago, =FSB=HandyNasty said:

under those settings + 100% mixture, i got 583 kph (364mph) at deck...

Kuban autumn, full fuel, extra ammo and 8 guns,

 

Did going above 65" shorten the mode timer?

 

330 mph IAS at 3000 m (Fw 190's weak spot). Thats about 11 km/h faster than 190 A-5 with gills closed, stab ahead and no outer wing guns. And 27-ish faster than A-3. Keeping that in mind can save a virtual life... Remove a pair of guns, or two, and you're even faster!

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11 minutes ago, LeLv76_Erkki said:

Did going above 65" shorten the mode timer?

i think yes but haven't tested it rigorously. Timer exceeded after 3-4 minutes (had game sped up so really not precise).

Plus it was only 1 test. To get more accurate picture of engine timer, you need multiple tests i think

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i was doing tests on stalingrad as i dont have kuban, probably its posible to get more speed there, on staling it goes to 572kmh ias, and warning shows up at 4min.

 

also when i tested it at 10000m, i see i get 388kmh ias, with all 100%, but inlet cowls at 70% insted 50%.

but then when i swith prop rpm on manual i can go to higher rpms then 2700, and get speed up to 416-420kmh ias, and after 5min warning shows up.

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2 hours ago, catchthefoxes said:

went to dive from 30k ft got myself all the way to 569 mph/ 915 kph ailerons ripped of at 559

Yep, this is one of the problems imo, ailerons rip off at speeds that they shouldn't. Control structural failure was only a problem for early P-47s.

3 hours ago, LeLv76_Erkki said:

Heres what I have now. Of course work in progress. Removing some guns make P-47 3-11 -ish km/h faster depending on how many you get rid of, power settings and altitude. It isnt too slow after all is it?

 

  Reveal hidden contents

P47vers.thumb.png.05110287da1bcb886ad0cf86a6b20f4f.png

 

P-47 should be faster than that, it's top speed should be (from the document that the devs showed) 438 mph (704 kmh) at around 24,000ft. (7,300m)

Edited by Legioneod
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