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Engine sound? Or the lack of?


RodBorza
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On the four P-47's flying today with working turbos ("Dottie Mae" (N47DM), "Hun Hunter XVI" (N9246B), 45-49385 (N47DF) and "Tallahassee Lassie" (N7159Z)), you can find videos of them starting up and the exhaust comes out both the waste-gates and the turbo.

 

If you can't find them, why should we be able to?

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The four Thunderbolts flying today with functioning turbos, showing smoke at startup and running on the ground, coming from both the waste-gates and turbo:

 

"Tallahassee Lassie" (N7159Z):

 

"Dottie Mae" (N47DM):

(startup at beginning of video - none of the other P-47's in the video have working turbos or stock exhaust setups)

(after the 2:18 mark, taxiing out, still smoking from the turbo)

 

45-49385 (N47DF)

(after the 1:28 mark - also, when watching this video, the first two P-47's to takeoff have no turbocharger and the exhaust is directly routed through stacks at the front, while the next two P-47's taking off both have working turbos and all of the interior exhaust and air ducting - note the difference in sound)

 

"Hun Hunter XIV" (N9246B)

("Wicked Wabbit", in the background, doesn't have a functioning turbo but has the exhaust directly routed back trough a replica turbo)

 

 

Besides these four, all of the rest of the 11 Thunderbolts currently flying don't have working turbos and have various means of expelling the exhaust.


Edited by Razorback51
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Okay, thanks.

 

How does 100% of the sound come out the turbo when most of the exhaust doesn't?

 

At lower altitudes the turbo isn't working as hard and I assume that most of the exhaust just by passes through the turbo ducting before reaching the exhaust stacks near the wing root; a longer trip at lower pressures than a 'normal' exhaust on a Corsair or Hellcat using the same engine with a different supercharging system.

 

cheers

 

horseback

[sIGPIC][/sIGPIC]"Here's your new Mustangs boys--you can learn to fly 'em on the way to the target!" LTCOL Don Blakeslee, late February 1944

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No, the waste gates bypass the exhaust before it ever goes down the pipes to the turbo in the rear. It would appear that some amount of exhaust (and sound?) always leaks through though.

 

ecb15af8b20c96702a2ecd0b4f1a43cd.jpg


Edited by SMH
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Its been said that the base sounds were recorded from the Duxford-based P-47, which is 'Nellie B', registered as G-THUN (used to be painted as 'No Guts, No Glory' back when owned by The Fighter Collection). It doesn't have a turbocharger and the exhaust setup is non-stock, with the exhaust routed to the rear fuselage and exiting out of two stacks near to where the turbo would be located. It does however have more of a P-47 muffled and "throaty" sound than some of the others flying today that have all of the exhaust dumped out the front via stacks in-place of the waste-gates (sounding more like Corsairs than Thunderbolts). I personally think a wonderful job has been done mixing in the whine of the turbo fan (as I believe to be the case), which of course should be completely separate from the base engine sounds anyway. Also, testing the backfiring, wearing headphones and looking to either the left or right side of the cockpit, when a backfire occurs I can distinctly hear it loudest and first from the front, and then an immediate, quieter pop coming from the back out the turbo, which seems very accurate to me as to how it really plays out on a stock P-47.

 

As has been covered already, it would be great to be able to hear the spooling up of the inertia starter as well as having the initial DCS-stock startup backfiring sound not be so loud or present at all (done right, starting up an R-2800 there should just be a smooth, gradual increase of cylinders firing off).


Edited by Razorback51
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I was messing around with the engine controls today and noticed you can also link the prop pitch lever to the throttle as well as the boost lever, so all three advance together. I experimented with it for a while but couldn't see a reason why you would fly like this in a combat setting.

 

Anyone know if there's any mention in a manual somewhere what situations you would have both levers locked to the throttle? like in a cruise configuration for example..

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I was messing around with the engine controls today and noticed you can also link the prop pitch lever to the throttle as well as the boost lever, so all three advance together. I experimented with it for a while but couldn't see a reason why you would fly like this in a combat setting.

 

Anyone know if there's any mention in a manual somewhere what situations you would have both levers locked to the throttle? like in a cruise configuration for example..

 

I think that this is has to something with under boosting engine.

I think you can link throttle and prop for landing approach or diving so when you reduce MP rpm will drop too. Reducing MP w/o RPM will kill this engine quit fast.

For cruise or for climb it make no sense for me, because in climb you need to adjust throttle to maintain safe MP

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I was messing around with the engine controls today and noticed you can also link the prop pitch lever to the throttle as well as the boost lever, so all three advance together. I experimented with it for a while but couldn't see a reason why you would fly like this in a combat setting.

 

Anyone know if there's any mention in a manual somewhere what situations you would have both levers locked to the throttle? like in a cruise configuration for example..

I just watched the Flying the P-47 collection from Zeno's Warbird Drive-In yesterday; I don't recall the specific reason the Captain narrating that section used, but I noticed that the link from the throttle to the Prop pitch only goes forward--you could push the Prop RPM forward with a throttle increase if they were linked, but you couldn't pull it back with a throttle decrease.

 

Truth in advertising here--the model they were discussing was a razorback with water injection, but no wide bladed props, so call it a pre-1944 model. The US insignia were roundels with stars, so that probably puts it before late summer of 1943; domestic training commands weren't nearly as concerned with the latest marking requirements as the combat units were.

 

cheers

 

horseback

[sIGPIC][/sIGPIC]"Here's your new Mustangs boys--you can learn to fly 'em on the way to the target!" LTCOL Don Blakeslee, late February 1944

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No, the waste gates bypass the exhaust before it ever goes down the pipes to the turbo in the rear. It would appear that some amount of exhaust (and sound?) always leaks through though.

 

ecb15af8b20c96702a2ecd0b4f1a43cd.jpg

 

The manual (p.50) states that the hot exhaust is also used to heat the air going to the carburetor in a heat exchanger system when there is danger of the carburetor icing up; this indicates to me that however the exhaust is routed out, some portion of it is always diverted, and the sound from the manifold is going to be muffled regardless. Some is also diverted to the guns as well, to keep them from freezing at high alts.

 

The exhaust just doesn't have the 'clean' route out of the engine most other types have.

 

Very cool picture though; where's the display located?

 

cheers

 

horseback

[sIGPIC][/sIGPIC]"Here's your new Mustangs boys--you can learn to fly 'em on the way to the target!" LTCOL Don Blakeslee, late February 1944

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The manual (p.50) states that the hot exhaust is also used to heat the air going to the carburetor in a heat exchanger system when there is danger of the carburetor icing up; this indicates to me that however the exhaust is routed out, some portion of it is always diverted, and the sound from the manifold is going to be muffled regardless. Some is also diverted to the guns as well, to keep them from freezing at high alts.

 

The exhaust just doesn't have the 'clean' route out of the engine most other types have.

 

Very cool picture though; where's the display located?

 

cheers

 

horseback

While I am an A&P, I haven't worked on a P47 but typically carb heat is just taken from the engine heat produced within the cowling and routed via scat tubing into the air inlet for the carburetor. Most carb ice is found on the back side of the throttle valve in the carburetor where low pressure will cause a drop in temperature, causing water molecules to stick.

 

In the cockpit, the port side lever left of the seat is what controls this valve to allow the ducted hot air into the carb intake. Typically for most recip engines during run-up you'll check for allowable RPM for both mags, carb heat, and if a constant speed prop check the governor. I was surprised to see carb heat not mentioned but did not know if it is that significant of a drop in performance for the D.Wasp.

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Here is a flyby in another sim...

 

Keep the volume low. Your speakers might get hurt...:pilotfly:

 

 

Fox

Eagle Dynamics, ceterum censeo: dare nobis ME CCLXII!

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In the video that Fox posted, that particular P-47 has all of the exhaust dumped out stacks at the front, with no lengthy exhaust or turbocharger influencing the sound as it does on a stock P-47. As such, that one and some others flying today sound more like a Corsair than a stock P-47.

 

Nice video Cromhunt, and great job sticking the wheel landing. I've always loved those markings too, back to the 1990's when Charles Osborn's P-47 was painted in those markings (same aircraft now painted "Tarheel Hal" with the Lone Star Flight Museum).


Edited by Razorback51
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Here is a flyby in another sim...

Keep the volume low. Your speakers might get hurt...:pilotfly:

Fox

Do you really think it is very loud? Please, listen to how well you hear people talking on the background of the flyby. No lofty tones and screams, ordinary conversation. And try to find a similar video with the same distance to the P51, for example

Best regards,

Kanstantsin Kuzniatsou (btd)

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Do you really think it is very loud? Please, listen to how well you hear people talking on the background of the flyby. No lofty tones and screams, ordinary conversation. And try to find a similar video with the same distance to the P51, for example

Sorry Konstantin. I didn't make the irony clear. You know, the simulation that's called reality...

I wanted to show, how silent the Jug is.

I love your work.

 

 

Fox

Eagle Dynamics, ceterum censeo: dare nobis ME CCLXII!

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I think P-47 is too loud compare to our V12. I could hear P-47 in K-4 while doing military power take off.

I9 9900KF Stock, Gigabyte Z390 Aorus PRO, Ram 32 GB G.skill, Palit Gamerock OC 3090, Hotas Warthog, T.Flight Rudder Pedals, 4K 49" screen.

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I think P-47 is too loud compare to our V12. I could hear P-47 in K-4 while doing military power take off.

Well, with max power we don't hear anything:

While with your params (2600 rpm and 1.4 ata) we can hear low bass sound of P-47 prop a little, not so loud I think

200 meters between us.

But is there any proof that we should not hear it at all with these params? :)

Best regards,

Kanstantsin Kuzniatsou (btd)

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FYI, here's a good one of Tallahassee Lassie, one of the few with a working turbo.

 

Note the smoke coming out of both the turbo and waste gates during startup. Would assume sound too. And I think I might hear the turbo whine in a few of the flybys.

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  • 2 weeks later...
Very nice cockpit cam video of the P-47:

 

 

 

 

That first vid you link, is when they flew over Evansville IN for our 4th of July celebration a few years ago. You can probably see me on the levee!

 

They do a pass over the LST docked, then further west over downtown proper, there were two of them. They thundered past us in formation (2), and it was glorious!

 

Evansville built half of all P-47's and we also kicked out more LST's than any other inland port. Also responsible for about 50% of all .50 cal munitions production. We were known as an "Armory City" - you can still see all the old ammo storage bunkers outside of town.

Pointy end hurt! Fire burn!!
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