Author Topic: Manifold Vs RPM Engine Sound levels  (Read 10447 times)

Offline Zimme83

  • Gold Member
  • *****
  • Posts: 3069
Re: Manifold Vs RPM Engine Sound levels
« Reply #30 on: September 18, 2016, 01:10:59 PM »
If prop rpm is at max and engine at idle the prop will windmill and keep the engine rpm over idle so the prop is driving the engine instead of the opposite.
''The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge'' - Stephen Hawking

Offline FLS

  • AH Training Corps
  • Plutonium Member
  • *******
  • Posts: 11594
      • Trainer's Website
Re: Manifold Vs RPM Engine Sound levels
« Reply #31 on: September 18, 2016, 01:16:47 PM »
If prop rpm is at max and engine at idle the prop will windmill and keep the engine rpm over idle so the prop is driving the engine instead of the opposite.

The question seems to be how much RPM at what airspeed.

Offline Traveler

  • Gold Member
  • *****
  • Posts: 3145
      • 113th Lucky Strikes
Re: Manifold Vs RPM Engine Sound levels
« Reply #32 on: September 18, 2016, 01:25:13 PM »
The question seems to be how much RPM at what airspeed.

That was not my original point, the relationship between Manifold Pressure and RPM appears to be the same as it was in AHII , except in AHII the engine noise was associated with Throttle (MAP) and a second sound, Prop Sound  was associated with RPM.  In AHIII the engine noise sound associated with Throttle is also associated with RPM. Thus when in a power off approach and I advance my RPM to High or Max RPM the sound is that of an engine increasing in power or at least that is how it sounds to me.
Traveler
Executive Officer
113th LUcky Strikes
http://www.hitechcreations.com/wiki/index.php/113th_Lucky_Strikes

Offline FLS

  • AH Training Corps
  • Plutonium Member
  • *******
  • Posts: 11594
      • Trainer's Website
Re: Manifold Vs RPM Engine Sound levels
« Reply #33 on: September 18, 2016, 01:40:29 PM »
That was not my original point, the relationship between Manifold Pressure and RPM appears to be the same as it was in AHII , except in AHII the engine noise was associated with Throttle (MAP) and a second sound, Prop Sound  was associated with RPM.  In AHIII the engine noise sound associated with Throttle is also associated with RPM. Thus when in a power off approach and I advance my RPM to High or Max RPM the sound is that of an engine increasing in power or at least that is how it sounds to me.

Sorry I wasn't clear. The question of how much RPM v air pressure is from the discussion with Colmbo.

RPM changes with no throttle change in a way it didn't in AH2 so there is a difference in the model with sound, RPM, thrust and the associated effects like gyroscopic precession.

Offline Pudgie

  • Silver Member
  • ****
  • Posts: 1280
Re: Manifold Vs RPM Engine Sound levels
« Reply #34 on: September 18, 2016, 01:47:15 PM »
Depends on the airplane.  Generally the Prop control is put in the high RPM position to facilitate a power increase if needed.

Modern day flying the B-17 and B-24 the RPM is left at 2000RPM (vs 2500 or 2700) during approach to help prevent having the prop drive the engine which leads to premature engine failure.  As the aircraft touch down the non flying pilot brings the prop control up to High RPM.

Just to put it out there, I've found in game that my Spitty matches up best on final when I set the RPM's to 2,000 as well w\ throttle holding boost around 2-4 lbs at the proper glide path.........

The landings are just beautiful at these power settings..........

 :aok

 :salute
Win 10 Home 64, AMD Ryzen 9 3900X, MSI MPG X570 Gaming Plus, GSkill FlareX 32Gb DDR4 3200 4x8Gb, XFX Radeon RX 6900X 16Gb, Samsung 950 Pro 512Gb NVMe PCI-E SSD (boot), Samsung 850 Pro 128Gb SATA SSD (pagefile), Creative SoundBlaster X7 DAC-AMP, Intel LAN, SeaSonic PRIME Gold 850W, all CLWC'd

Offline Traveler

  • Gold Member
  • *****
  • Posts: 3145
      • 113th Lucky Strikes
Re: Manifold Vs RPM Engine Sound levels
« Reply #35 on: September 18, 2016, 01:48:42 PM »

RPM changes with no throttle change in a way it didn't in AH2 so there is a difference in the model with sound, RPM, thrust and the associated effects like gyroscopic precession.
Throttle and RPM work exactly the same for me.  I could make independent throttle and RPM changes in AH2 and AH3.
Traveler
Executive Officer
113th LUcky Strikes
http://www.hitechcreations.com/wiki/index.php/113th_Lucky_Strikes

Offline FLS

  • AH Training Corps
  • Plutonium Member
  • *******
  • Posts: 11594
      • Trainer's Website
Re: Manifold Vs RPM Engine Sound levels
« Reply #36 on: September 18, 2016, 01:55:04 PM »
Throttle and RPM work exactly the same for me.  I could make independent throttle and RPM changes in AH2 and AH3.

If you dive to high speed you will see RPM increase with no change in settings. If you zoom climb to a stall you will also see an RPM change. Those are new as well as the prop pitch governor lag when you change RPM.

Offline ONTOS

  • Silver Member
  • ****
  • Posts: 1140
Re: Manifold Vs RPM Engine Sound levels
« Reply #37 on: September 18, 2016, 02:08:56 PM »
OK, the engine sounds are basically  the same in AH III as in AH II, but that is the default sound. The customs sounds on AH II are very different. When I cut the throttle, the engine stays just as loud, but the pitch changes. If you are looking at the default sounds they are really different from the custom sounds and worse.

Offline FLS

  • AH Training Corps
  • Plutonium Member
  • *******
  • Posts: 11594
      • Trainer's Website
Re: Manifold Vs RPM Engine Sound levels
« Reply #38 on: September 18, 2016, 02:14:24 PM »
...When I cut the throttle, the engine stays just as loud, but the pitch changes. ...

That's how it was in AH2, and since that's not accurate it was changed for AH3. I understand that you prefer the old model.

Offline hitech

  • Administrator
  • Administrator
  • *****
  • Posts: 12304
      • http://www.hitechcreations.com
Re: Manifold Vs RPM Engine Sound levels
« Reply #39 on: September 18, 2016, 02:31:59 PM »
That was not my original point, the relationship between Manifold Pressure and RPM appears to be the same as it was in AHII , except in AHII the engine noise was associated with Throttle (MAP) and a second sound, Prop Sound  was associated with RPM.  In AHIII the engine noise sound associated with Throttle is also associated with RPM. Thus when in a power off approach and I advance my RPM to High or Max RPM the sound is that of an engine increasing in power or at least that is how it sounds to me.

Your post is incoherent because of your terms. ( engine noise was associated with Throttle) I have no idea what this means.
And also I have no idea what this means. ( Prop Sound  was associated with RPM.  ).

Please use the terms Frequency and volume.

In ah3 Manifold pressure is primarily controlling volume (also other sound changes but not frequency), RPM control is changing the frequency of the sound.

The question seems to be how much RPM at what airspeed.

This is a valid question that is not an easy answer and varies with planes and props.

HiTech






Offline colmbo

  • Gold Member
  • *****
  • Posts: 2246
      • Photos
Re: Manifold Vs RPM Engine Sound levels
« Reply #40 on: September 18, 2016, 11:13:22 PM »
So you're saying the RPM drops but not as much as it should?

Yes, it seems that way to me.  The sound matches the RPM so not so much a sound problem as an engine modeling glitch.
Columbo

"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."

Fate whispers to the warrior "You cannot withstand the storm" and the warrior whispers back "I AM THE STORM"

Offline Chalenge

  • Plutonium Member
  • *******
  • Posts: 15179
Re: Manifold Vs RPM Engine Sound levels
« Reply #41 on: September 18, 2016, 11:29:38 PM »
Why not make some sounds for us all then? I'm sure with your experience they will be perfect!

Anyone working on that?
If you like the Sick Puppy Custom Sound Pack the please consider contributing for future updates by sending a months dues to Hitech Creations for account "Chalenge." Every little bit helps.

Offline FLS

  • AH Training Corps
  • Plutonium Member
  • *******
  • Posts: 11594
      • Trainer's Website
Re: Manifold Vs RPM Engine Sound levels
« Reply #42 on: September 18, 2016, 11:55:58 PM »
Yes, it seems that way to me.  The sound matches the RPM so not so much a sound problem as an engine modeling glitch.

Do you recall what the B-17 and B-24 RPM rise to from 2000 when the co-pilot sets max RPM on touch down?

Offline colmbo

  • Gold Member
  • *****
  • Posts: 2246
      • Photos
Re: Manifold Vs RPM Engine Sound levels
« Reply #43 on: September 19, 2016, 07:31:57 AM »
Do you recall what the B-17 and B-24 RPM rise to from 2000 when the co-pilot sets max RPM on touch down?

The RPM doesn't increase at all, the engines are pulled to idle during the flare for landing.  To increase RPM would require an increase in throttle.
Columbo

"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."

Fate whispers to the warrior "You cannot withstand the storm" and the warrior whispers back "I AM THE STORM"

Offline earl1937

  • Gold Member
  • *****
  • Posts: 2290
Re: Manifold Vs RPM Engine Sound levels
« Reply #44 on: September 19, 2016, 10:35:51 AM »
Real life you hear a change in engine sound with RPM changes.  Sometimes only a little, sometimes a lot (like if you roll the RPM way back at high manifold settings)
:airplane: Correct and what I think must of these guys don't undstand is with constant speed props, prop sound is only going to change down around 12 inches of manifolf pressure. Same way with decreasing RPM, say from 2500RPM to 2,000 RPM, sound will change as the manifold pressure will increase, giving the engine or engines a different sound.
Blue Skies and wind at my back and wish that for all!!!