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P-47 supercharger

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Posted (edited)

I know the P-47 also has a turbo-charger with gauge and blinking lite to tell if it is operating.

what about the supercharger? i'm begining to wonder if the supercharger is even working. is there anyway to test this?

 

i would think would just the the big prop alone the P-47 would have some acceleration to 250mph at sea level. i don't expect its top speed to increase, but just reading and watching some of the historical accounts. i thought the engine along with the prop could at least provide some acceleration.

right now its only advantage in a dog fight at low atlitudes is the use of flaps in a turning engagement. but once my opponent reasons he can't out turn me, most just level out. at this point i,m normally at 150mph and also level out only to watch them fly off into the distance and watch my mph gauge move like the hour hand on a clock.

 

Edited by -325th-Porky-
added gauge

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The supercharger in the P-47 is geared to the engine and as such is always working. You can check that by flying at the deck, closing the (turbo) boost lever and fully opening throttle level and RPM. You will see that manifold gauge exceeds 45" which wouldn't be possible without a working supercharger.

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2 hours ago, Ehret said:

The supercharger in the P-47 is geared to the engine and as such is always working. You can check that by flying at the deck, closing the (turbo) boost lever and fully opening throttle level and RPM. You will see that manifold gauge exceeds 45" which wouldn't be possible without a working supercharger.

ok, thanks.

working as intended.

hard to believe its the same engine as in the F-4 and F-6F without a turbo. must have been overhyped too.

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20 minutes ago, -325th-Porky- said:

ok, thanks.

working as intended.

hard to believe its the same engine as in the F-4 and F-6F without a turbo. must have been overhyped too.

 

The Thunderbolt is big and heavy plane; what you were expecting? Still, in the sim you can climb about 3500ft/m from SL using water injection. The turbo improves relative performance significantly but you have to fly +20k ft. It's not the P-47D fault that the BOBP doesn't have objectives at high altitude; nor it lacks 150 octane fuel. That there are hordes of K4s in multi-player doesn't help.

 

https://www.youtube.com/watch?v=UHUmWTnBuhU

- a very good video about the P-47 climb performance and comparisons with other planes.

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Posted (edited)
2 hours ago, Ehret said:

 

The Thunderbolt is big and heavy plane; what you were expecting? Still, in the sim you can climb about 3500ft/m from SL using water injection. The turbo improves relative performance significantly but you have to fly +20k ft. It's not the P-47D fault that the BOBP doesn't have objectives at high altitude; nor it lacks 150 octane fuel. That there are hordes of K4s in multi-player doesn't help.

 

https://www.youtube.com/watch?v=UHUmWTnBuhU

- a very good video about the P-47 climb performance and comparisons with other planes.

i know its a big and heavy plane, i'm not expecting to do a 9g acceleration where the pilot blacks out. its not the P-47s climb or even dive performance... its the P-47's acceleration in level flight. i'm not expecting even close to BF 109 performance even with 25% fuel, 4 .50 cal(no extra ammo) and no other ordinance.

i do have flight experience in rotary wing, not fixed wing aircraft. i imagine some of the basic flight principles translate over.

 

with 25% fuel and 4 .50 cal, cowl flaps at 0%, inlet flap 50%, oil radiator 0%, rpm 2750, throttle 100%, water injection on, turbo 100%. its the acceleration from 150mph to 250mph in level flight (i'm not even expecting anything more than 250mph) at "low level" (below 7000ft), coming out of a turn is quite disapointing even for such a brick of a plane. just reading up on the F6F(9,022lbs) and F4U(8855lbs) which aren't quite as heavy but have the same engine and no turbo. they seemed to have no problem in the acceleration department. i know these are carrier aircraft, and being heavy needed even more acceleration and power than the P-47 on takeoff. so using that reasoning i thought the P-47 would have some ability to accelerate from 150mph to 250mph (not even considering that big prop) at least long enought to get a long distance shot on BF 109 coming out the same turn before it speeds away.

 

 

i am familiar with Greg as well as I Fly Central. Sheriff's Sim Shack, The Air Combat Tutorial and alot of other historical and pilot interviews.

Edited by -325th-Porky-
added engine settings

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3 hours ago, -325th-Porky- said:

hard to believe its the same engine as in the F-4 and F-6F without a turbo. must have been overhyped too.

Both P-47 and F-4 have two stage turbo systems. In both cases, the first stage supercharger is directly connected to the crankshaft.

 

In the F-4, you have a second stage, two speed supercharger and intercooler system.You have a "off", "low" and "high" gear in the F-4 that you can select by a lever, whereas in the P-47 it allows you to gradually increase the second stage MAP boosting without it eating power from the crankshaft. It makes the P-47 more powerful on the shaft power output at the same rating, while also making most efficient use of the engine all the way up to critical altitude of the turbocharger.

 

The downside of the turbocharger is that exhaust gases are ejected slower and you cannot benefit fom this "jet" anymore. Then again, radial engines have exhaust stacks in away that probably make less efficient use of that then the inline engines featuricng stacks to specifically generate trust.

 

1 hour ago, -325th-Porky- said:

reading up on the F6F(9,022lbs) and F4U(8855lbs) which aren't quite as heavy but have the same engine and no turbo. they seemed to have no problem in the acceleration department.

The P-47 was not really that much worse than the two mentioned. It couldn't follow a Tempest in initial accelleration, even at altitudes where it became faster then the Tempest.

 

The P-47 was well liked amoung its crews, not just for the roomy and (relatively) safe office space it provided, but also for its stability in dives that made it so good as a ground pounder. On the other hand, it is above 26'000 ft where the P-47 really beginns to find its breath. The 109 cannot follow it in boom and zoom maneuvers up there. Coupled with very responsive ailerons even at high speeds, a stable gun platform and a very heavy punch, you get a good package.

 

Turning circles flaps down with 109's is just gaming. Gaming the game in fact.

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Posted (edited)
1 hour ago, ZachariasX said:

Both P-47 and F-4 have two stage turbo systems. In both cases, the first stage supercharger is directly connected to the crankshaft.

 

In the F-4, you have a second stage, two speed supercharger and intercooler system.You have a "off", "low" and "high" gear in the F-4 that you can select by a lever, whereas in the P-47 it allows you to gradually increase the second stage MAP boosting without it eating power from the crankshaft. It makes the P-47 more powerful on the shaft power output at the same rating, while also making most efficient use of the engine all the way up to critical altitude of the turbocharger.

 

The downside of the turbocharger is that exhaust gases are ejected slower and you cannot benefit fom this "jet" anymore. Then again, radial engines have exhaust stacks in away that probably make less efficient use of that then the inline engines featuricng stacks to specifically generate trust.

 

The P-47 was not really that much worse than the two mentioned. It couldn't follow a Tempest in initial accelleration, even at altitudes where it became faster then the Tempest.

 

The P-47 was well liked amoung its crews, not just for the roomy and (relatively) safe office space it provided, but also for its stability in dives that made it so good as a ground pounder. On the other hand, it is above 26'000 ft where the P-47 really beginns to find its breath. The 109 cannot follow it in boom and zoom maneuvers up there. Coupled with very responsive ailerons even at high speeds, a stable gun platform and a very heavy punch, you get a good package.

 

Turning circles flaps down with 109's is just gaming. Gaming the game in fact.

i wasn't aware of the P-47 having a "2" stage turbocharger... just the single stage supercharger. i also thought the F4U and F6F lacked a turbocharger and just had a supercharger.

 

i understand the difference in the turbocharger being exhaust driven and the supercharger being gear driven. also that the exhaust driven turbo is going to "lag" just because it has to run up to speed, were as the gear driven supercharger is more immediate. also the advantages of the turbocharger over the supercharger at higher altitudes.

 

any 109 pilot right now isn't going above 20000ft, he's got no reason.  most i see are at 10'000-7'000ft. well below any altitude the P-47 is supposed to operate as a fighter.

 

i ground attack and then go to cover a friendly objective climbing to 10'000ft, which is good for one BNZ before they are on to me. generally i'm spotted before i get the chance, and no 109 is going to follow me up to 20'000ft+ and i still have to cover the objective. if i'm lucky the 109 will try and make it a turn fight after i've gotten a BNZ in and i'm going to use flaps to game the game. its when the 109 decides to break from the fight into level flight, and i have to go full throttle, water injection and raise the flaps that the P-47 fails... its lack of acceleration.

 

Ehret answered my question as how to tell if the supercharger was working or not. the P-47's acceleration is what it is. so i'll just deal with it and should PTO come about i'll not be surprised at the F4U and F6F performance.

 

i found best flight performance with 25% fuel, 4x.50 with no extra ammo and just cover an objective. but you'll spent at great deal of your time at the airfield.

 

 

Edited by -325th-Porky-
added F6F

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May as well just fly a P-40 if you're just going to carry 4 MGs. :scratch_one-s_head:

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Yes, it's at altitude that the Jug shines. No question about it. As matter of fact, Col. Zemke used to order the pilots of the 56th Fighter Group to break off attacks on German fighters if the fight got below 15,000 feet. This wasn't always followed, but it does show what he thought about the Thunderbolts performance at low altitude.

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Technically ZackhariasX is correct the P-47 has two superchargers.  The second is a turbosupercharger (often shortened to turbocharger), because it performs the same function of compressing the air to make it more dense.  As pointed out, turbo means it is exhaust gas driven instead of geared to the engine like most superchargers.  The reference to both P-47 and F4U having turbochargers is a slip up.  The F4U doesn't have a turbosupercharger, it has a two-stage, two-speed supercharger system (as does the F6F), both geared to the engine.

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11 hours ago, -325th-Porky- said:

with 25% fuel and 4 .50 cal, cowl flaps at 0%, inlet flap 50%, oil radiator 0%, rpm 2750, throttle 100%, water injection on, turbo 100%. its the acceleration from 150mph to 250mph in level flight (i'm not even expecting anything more than 250mph) at "low level" (below 7000ft), coming out of a turn is quite disapointing even for such a brick of a plane.

 

Set the mixture to 100% when on water injection. It shouldn't be necessary but in the sim it is if you want full power. Perhaps, it will help.

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10 hours ago, Ehret said:

 

Set the mixture to 100% when on water injection. It shouldn't be necessary but in the sim it is if you want full power. Perhaps, it will help.

haven't tried that, I thought just keeping it in "auto rich" would do and that full rich was just used when "auto rich" fails.

i'll give a try.

thanks.

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It's a bit weird. When I have the P-47 run on the deck, when on water injection, I do get (omn aquick check) ~2 mph speed increase running on "full rich" vs "auto rich". It should really be only a (even richer) fallback setting when auto rich doesn't work. But it accellerates ok. Especially if you can push the nose down a bit.

 

Other than that, you produce smoke with the throttle all forward, no water injection running on "full rich". Back to "auto rich" there is no smoke trail. It is a bit surprising, to get a speed increase in case of the water injection, as overly rich mixtures decrease power output, once you pass from "rich" mixture to "rich-rich". Water injection is really meant to also lean out your mixture, something you don't get (or less so) from water/methanol injection, as methanol does enrich your mixture. It keeps the tank from freezing at altitude though.

 

Still, I think 2 mph of eventual speed gain is a bad trade for making yourself visible to anyone on the map by having a smoke trail.

 

But as long as levers in quadrants with discrete settings don't "click" into their positions, it is still a bloody nuisance to find the correct postition (w/o technochat). The angles at which one looks at these levers don't make it that easy to see.

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24 minutes ago, -325th-Porky- said:

haven't tried that, I thought just keeping it in "auto rich" would do and that full rich was just used when "auto rich" fails.

i'll give a try.

thanks.

 

In game you have better speed when using boost if you have mix not on auto but on 100%. 100% without boost will slow you down.

 

also abow 7km you can turn on manual rpm and raise it up to 3000rpm for few min (below that alt you dont gain anything doing that) and abow 9km your inlet flaps should be raised from 50% that is best for alt below to 70% for best speed. 

 

But nothing will help mutch, vs k4s that you see online your to slow even if you have all correctly set

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19 hours ago, -325th-Porky- said:

any 109 pilot right now isn't going above 20000ft, he's got no reason.  most i see are at 10'000-7'000ft. well below any altitude the P-47 is supposed to operate as a fighter.

On TAW it is normal. My cruising alt is 4.5km and if I am doing top cover I cruise at 7km. It is no exception to fight at 7 or 8km. Hell I even fought two La5FNs at 10km while I was in 109G2. I didnt sweat like that in a long time.

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speaking of G-2 at high up, is it normal for G-2 to outperform p-47 at 11km in speed? 

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6 hours ago, CptSiddy said:

speaking of G-2 at high up, is it normal for G-2 to outperform p-47 at 11km in speed? 

IMHO it shouldn't since G2 loses breath above 6km. Current Jug should outperform even K4 above 7km.

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6 hours ago, CptSiddy said:

speaking of G-2 at high up, is it normal for G-2 to outperform p-47 at 11km in speed?  

 

No it´s not, but it´s a general high alt problem

 

 

 

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Posted (edited)
6 hours ago, CptSiddy said:

speaking of G-2 at high up, is it normal for G-2 to outperform p-47 at 11km in speed? 

 

They adjusted high alt speds with one of updates, i see in 3010 tests i did that 109G2 no longer have that high speed up high that made it faster then P-47, now its slower

109G2 vs P47 (for 109g2 that 2nd line is manualy raising rpm for 2min )

Spoiler

339j7ko.jpg

 

26 minutes ago, CSAF-D3adCZE said:

IMHO it shouldn't since G2 loses breath above 6km. Current Jug should outperform even K4 above 7km.

 

even DB K4 is faster then P-47 up high, and can fly longer on combat and emergancy, 1.98 is faster on all alts, exept maybe 12km

 

109K4 vs P47 ( first line is combat 2nd max )
 

Spoiler

5upbpl.jpg

 

Edited by 77.CountZero

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On 3/12/2019 at 9:32 AM, 77.CountZero said:

 

They adjusted high alt speds with one of updates, i see in 3010 tests i did that 109G2 no longer have that high speed up high that made it faster then P-47, now its slower

109G2 vs P47 (for 109g2 that 2nd line is manualy raising rpm for 2min )

  Reveal hidden contents

339j7ko.jpg

 

 

even DB K4 is faster then P-47 up high, and can fly longer on combat and emergancy, 1.98 is faster on all alts, exept maybe 12km

 

109K4 vs P47 ( first line is combat 2nd max )
 

  Reveal hidden contents

5upbpl.jpg

 

is it because the FM for the P-47 isn't finnished?

I really have yet to test it above 20'000 ft... 

so I'm going to have remember its "timed" limitations if i hope to outpreform German a/c? it's my understanding that certain a/c can regenerate their "timed" limitations? if the answer to both are yes, i'll deal with it. i just don't want to beat my head against the wall thinking its something i'm doing wrong.

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20 minutes ago, -325th-Porky- said:

so I'm going to have remember its "timed" limitations if i hope to outpreform German a/c? it's my understanding that certain a/c can regenerate their "timed" limitations? if the answer to both are yes, i'll deal with it. i just don't want to beat my head against the wall thinking its something i'm doing wrong.

 

If you depleted whole timer in P-39/40/47 you will have "rest" the engine for 25m straight on the nominal setting to recover combat and emergency. In practice it is much faster just to RTB and take off again.

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5 minutes ago, Ehret said:

 

If you depleted whole timer in P-39/40/47 you will have "rest" the engine for 25m straight on the nominal setting to recover combat and emergency. In practice it is much faster just to RTB and take off again.

thanks, as it is now that about my RTB due to fuel anyway.

is the regen/rest time same for all a/c? i'm thinking it might be more advantageous to jump someone on their way out after having expended their combat/emergency limitations.

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51 minutes ago, -325th-Porky- said:

thanks, as it is now that about my RTB due to fuel anyway.

is the regen/rest time same for all a/c? i'm thinking it might be more advantageous to jump someone on their way out after having expended their combat/emergency limitations.

 

I know about P-39/40/47 only. Well... I recall that the La-5 (not F) needs about 3m of continuous to recharge 1m of full boost. Yaks, LaGG and La-5F don't seem to have any timers. 109s/190s have 30m of combat and it's quite strong - don't expect them to be handicapped by depleted timer often if at all.

 

For the most survivable tactic if you are flying one of the American planes you should climb; even a bit higher than supercharger critical altitude. Then you can patrol in very slight descent and set the engine to little higher than the nominal setting. That way once engaged the timer will be almost fresh and you had an adequate cruise speed.

 

And that is really silly... No Russian pilot was flying the P-40/P-39 like that in eastern front. Apparently we have an alternative history reflected in "the sim" when some technical aspects are concerned.

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@77.CountZeroHow do you configute/run the altitude/speed tests?

 

I've previously found that setting the engine to 60" @2550RPM gets the full 15 minutes of water injection and was wondering how much real speed penalty that entailed? 

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Posted (edited)
3 hours ago, Voyager said:

@77.CountZeroHow do you configute/run the altitude/speed tests?

 

I've previously found that setting the engine to 60" @2550RPM gets the full 15 minutes of water injection and was wondering how much real speed penalty that entailed? 

 

I select autum map in quick mission and start from airstarts, default loudout 70% fuel, for max speed i used ~2550 rpm (below 7km, 2700 abow), boost on , turbo % set on what ever is needed to set rpm at ~2550, trottle 100%, mix 100%, inlet 50%, outlets 0%. For that left line, that is combat regime, same settings exept boost is off and mix 80%, also abow 9km 70% inlet with both gives better resoult then 50%. By manualy raising rpm up to 3000rpm you could go even faster for few min abow 7km.

 

I run that setting also to get max boost time, and your slower then if you used max MP for around ~20kmh

 

 

5 hours ago, -325th-Porky- said:

is it because the FM for the P-47 isn't finnished?

I really have yet to test it above 20'000 ft... 

so I'm going to have remember its "timed" limitations if i hope to outpreform German a/c? it's my understanding that certain a/c can regenerate their "timed" limitations? if the answer to both are yes, i'll deal with it. i just don't want to beat my head against the wall thinking its something i'm doing wrong.

They always say FM is never finished, but from what i see speeds are exactly as in doc they show they based airplane, so its correct as it can be in max speed

 

not all airplanes in game have same recharg for combat emergancy or boost, and they also dont spend it same, some can spend only emergancy and not combat at same time and some like P-47, spend all at same time and can recharg normaly only on continues and are at disadvantage

Edited by 77.CountZero
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Why timers?  Things not actually simulated to atmospheric and run conditions but just a simple timer?

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On 6/11/2019 at 2:37 AM, MercCrom175 said:

Why timers?  Things not actually simulated to atmospheric and run conditions but just a simple timer?

 

“Oh, my sweet summer child, what do you know of timers..."

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