Cessna 310R Redux and Engine Sounds

[JesC 88]

First, let me say this is an exceptional simulation. Even at full price I think I have gotten a real bargain. Thanks very much for your efforts.

My question concerns the connection between manifold pressure and sound. I have noticed that there isn't any perceptible sound difference in flight when reducing the manifold pressure. At least not until slow and below 15" or so. I am just wondering if this is entirely correct or not. I find it a little difficult to recognize fine power adjustments during approach and landing and when in the traffic pattern.

Just wanted to gain a better understanding of this behavior.

Thanks for any feedback.

Jesse

[StewartH 66]

I have noticed the same thing, Jesse.  The pitch level may be entirely due to prop rpms, but I don't know for sure.

[raymie 81]

I have noticed the same regarding engine sound and manifold pressure (throttle) adjustments. Decrease in throttle does not bring a decrease in engine sound (i.e. reduction in manifold setting during descent or on approach to slow down indicated airspeed). On final approach prop adjustment to full pitch brings an increased pitch sound as that should be. 

Any clarification would be appreciated. I too am enjoying the Redux version a lot. The autopilot is a learning curve somewhat but getting use to it.

[fppilot 4,335]

12 minutes ago, raymie said:

The autopilot is a learning curve somewhat but getting use to it.

[Ron Attwood 3,464]

It's the same with their Beaver. No change in tone or sound level until you get below...I forget, but very close to the throttle being practically closed. Maybe just a P3D/FSX phenomenon. 

[Les Parson 99]

I believe it is correct and quite nicely done. I was thrilled to learn Milviz got this right. The following is a quote from Bill (Whamil77) on the same topic regarding the Beech Baron B58: 

"The pitch change with RPM change is exactly right.  The RPM of the engines is not determined by the throttle once in the RPM governing range (approximately 1500 RPM).  The propeller governors adjust the pitch of the propeller blades to maintain the RPM selected by the pilot, therefore the pitch doesn't change with throttle.  The fact that you ask tells me just how conditioned these incorrect simulations have made so many simmers.  I hear there were many folks that sent trouble tickets about X-plane11 and the pitch changes with RPM when they made the change to the proper engine physics."

Note: C310R & B58 engines are normally both Continental 6-cylinder IO-520s (I think). 

[shivers9 1,174]

5 minutes ago, Les Parson said:

I believe it is correct and quite nicely done. I was thrilled to learn Milviz got this right. The following is a quote from Bill (Whamil77) on the same topic regarding the Beech Baron B58: 

"The pitch change with RPM change is exactly right.  The RPM of the engines is not determined by the throttle once in the RPM governing range (approximately 1500 RPM).  The propeller governors adjust the pitch of the propeller blades to maintain the RPM selected by the pilot, therefore the pitch doesn't change with throttle.  The fact that you ask tells me just how conditioned these incorrect simulations have made so many simmers.  I hear there were many folks that sent trouble tickets about X-plane11 and the pitch changes with RPM when they made the change to the proper engine physics."

Note: C310R & B58 engines are normally both Continental 6-cylinder IO-520s (I think). 

Thanks for that info Les. I did not know that and kelp reducing the throttles on approach and did not notice the airspeed and smashed into the approach lights at KPNS. LOL teeth hair and eyeballs for miles! LOL

[Les Parson 99]

2 minutes ago, shivers9 said:

Thanks for that info Les. I did not know that and kelp reducing the throttles on approach and did not notice the airspeed and smashed into the approach lights at KPNS. LOL teeth hair and eyeballs for miles! LOL

I've asked Bill (Whamil77) to come over here to this forum and add comment; he's the expert. 

[Les Parson 99]

1 hour ago, Ron Attwood said:

It's the same with their Beaver. No change in tone or sound level until you get below...I forget, but very close to the throttle being practically closed. Maybe just a P3D/FSX phenomenon. 

You've had 24 hours to produce half a dozen or more C310 Redux repaints. What's the hold-up? 

- Just kidding of course. 

[StewartH 66]

14 minutes ago, Les Parson said:

I believe it is correct and quite nicely done. I was thrilled to learn Milviz got this right. The following is a quote from Bill (Whamil77) on the same topic regarding the Beech Baron B58: 

"The pitch change with RPM change is exactly right.  The RPM of the engines is not determined by the throttle once in the RPM governing range (approximately 1500 RPM).  The propeller governors adjust the pitch of the propeller blades to maintain the RPM selected by the pilot, therefore the pitch doesn't change with throttle.  The fact that you ask tells me just how conditioned these incorrect simulations have made so many simmers.  I hear there were many folks that sent trouble tickets about X-plane11 and the pitch changes with RPM when they made the change to the proper engine physics."

Note: C310R & B58 engines are normally both Continental 6-cylinder IO-520s (I think). 

This is fantastic!  Another reason to get this aircraft for those who don't already have it.  I suspected this might be the reason, but I'm not a RL pilot, so wasn't sure.

[Ron Attwood 3,464]

34 minutes ago, Les Parson said:

You've had 24 hours to produce half a dozen or more C310 Redux repaints. What's the hold-up? 

- Just kidding of course. 

I've only done 5. Sorry. Did you know, there are 16 texture sheets per airplane?

[JesC 88]

Well... I don't want to interrupt the repaint discussions; but as far as my experience goes constant speed props are only capable of maintaining RPM within a relatively narrow power range. The engine sounds and even the prop sounds should be heard when manifold pressure is reduced. Especially when reduced significantly.

With all due respect to Whamill77 the manifold pressure and the prop rpm settings are constantly interacting and neither one is the sole influence on sound. What Whamill77 said may be more applicable to turboprops.

All I know is that I have to be very careful that I refer to the engine gauges when landing  this aircraft and I don't get any help from sounds. Not what I recall from my real world experiences. But then I'm not the expert.

Jesse

[dbw1 443]

I flew an 310r for approx 1500 hrs Doug forest fire suppression and I think they nailed the sounds right on. A lot of the sound is from engine rpm and so when the mp is decreased from take off to climb power (25”/2500rpm) the noise level will decrease with rpm reduction and again to cruise power 23”/2300rpm. When you bring up the power for takeoff the sounds to me are right on.....it really adds to the enjoyment of this MilViz 310r. This is now my favourite piston twin in P3d.

[JesC 88]

8 minutes ago, dbw1 said:

 A lot of the sound is from engine rpm and so when the mp is decreased from take off to climb power (25”/2500rpm) the noise level will decrease with rpm reduction and again to cruise power 23”/2300rpm. When you bring up the power for takeoff the sounds to me are right on.....it really adds to the enjoyment of this MilViz 310r. This is now my favourite piston twin in P3d.

I agree. But I don't think that you have addressed the sounds at lower power (mp) settings. When manifold pressure is reduced below cruise power settings I would also anticipate some sound reductions and rpm decreases.

BTW I have more than a few hours flying 310's and 320's myself. Nonetheless I don't think that makes me an expert.

I'm just trying to understand this better. I'm suspecting there may be some sim based limitations that result in the use of only rpm or mp influenced sounds. Hopefully at some point Milviz may offer some insight to their reasoning and  methodology. Given the depth of this simulation I am sure this is something they have given a great deal of thought, study and consideration.

At least I have established that this is not an anomaly of my install. Progress!! :-)

Jesse

 

[Wing 32]

When the sim starts the fuel levers are set to "off" but the engines are running just fine.

With the fuel levers correctly set to one of the tanks while flying, turning them "off" causes no change in engine sound. The aircraft looses airspeed (or yaws into the dead engine if you only cut one fuel lever), but the engine sound doesn't change at. It's like the only sound is coming from the props. I defer to dbw1 when it comes to judging what a real 310 sounds like, but it seems so me a 285HP internal combustion engine sitting a few feet from your head has got to generate some noise of its own, it can't be all prop noise.