Engine surging

[vmilner]

Hello,

I am experiencing the weirdest behavior of the engine surging in flight -- see video attached. 

It behaves as if I am moving the throttle back and forth periodically, full range. It feels very realistic: all engine parameters, as well as the prop and even the pitch of the plane, are all "responding" to these oscillations in power! So first I thought it's a simulated failure, but I double-checked that the failures checkbox is unchecked and also pressed "Fix all systems". I also re-calibrated the yoke twice, but the strange behavior persists.

Any advice of how to deal with it?

Thanks,

Valery

[Cameron]

Engine surging is typically related to low frame rates. What are your computer specs?

[vmilner]

Hi Cameron,

The computer is Intel i5-12400 2.5GHz with 12GB RAM. 

The graphics card is Nvidia GT 730 with 2 GB, 901MHz clock and the latest Vulcan-supporting driver 473.81.

What is the bottleneck here?

Thanks,

Valery

 

[Cameron]

20 minutes ago, vmilner said:

The graphics card is Nvidia GT 730 with 2 GB, 901MHz clock and the latest Vulcan-supporting driver 473.81.

This is what's killing you more than anything.

The CPU is "okay." That GPU is...old (putting it very nicely).

[vmilner]

I see. X-Plane says anything with more than 1GB and Vulcan support will do, so I thought it's enough.

Can you please recommend a not-too-fancy card that will work better?

[Cameron]

3 hours ago, vmilner said:

X-Plane says anything with more than 1GB and Vulcan support will do, so I thought it's enough.

Minimum requirements are kind of just that...the minimum required specs for something to even run. It doesn't mean run good.

When you start piling any kind of add-ons to X-Plane, you are asking more of it. In such cases the minimum specs are really not going to cut it.

Speaking specifically to the Entegra SR22, the minimum and suggested are:

• Modern CPU with 4+ Cores (6+ Cores recommended)
• 16+ GB RAM
• NVIDIA or AMD Graphics Card with 4+ GB VRAM (6+ GB recommended)

AMD has been prone to issues at times in X-Plane, so I would stick with Nvidia. What's within your budget will be up to you, but the specs above are what will make your experience more enjoyable.

[vmilner]

Thanks Cameron, this was very helpful.

I had a GTX 1060 nvidia card with 4 GB in my other computer, swapped the two, and the engine surges stopped. Everything runs pretty smooth all around now despite the weak CPU. I am using the sim to practice IFR flying, so I don't need high quality scenery or texture, as long as the engine and the avionics work. And now they seem to work well. 

In fact, even the Avidyne's IFD XTrainer app seems to run more consistently, i.e. with fewer and smaller oscillations in the NAV mode. I wonder if that known problem is also related to the GPU power? Any comments on that subject would be much appreciated.

 

Thanks again!

Valery

[Cameron]

On 11/11/2022 at 5:15 PM, vmilner said:

In fact, even the Avidyne's IFD XTrainer app seems to run more consistently, i.e. with fewer and smaller oscillations in the NAV mode. I wonder if that known problem is also related to the GPU power? Any comments on that subject would be much appreciated.

When X-Plane is running at a low frame rate, the data feed rate to XTrainer is also going to be cut back. I wouldn't so much call it a "problem" as much as I would an expected result.

[vmilner]

I see. Is there a way to know what frame rate is the XP running at? Other than the warning message when it's too low.

[Pils]

6 hours ago, vmilner said:

I see. Is there a way to know what frame rate is the XP running at? Other than the warning message when it's too low.

Data output in the settings, display fps on screen.

[vmilner]

Thanks!

[vmilner]

I am at around 60 fps with all graphics feature at minimum, and I still get an occasional oscillation in the tracking direction when driven by the Avidyne Trainer XP in the NAV mode. Is there anything else I could tweak to eliminate this?

Thanks! 

[Pivot]

On 11/15/2022 at 11:19 AM, vmilner said:

I am at around 60 fps with all graphics feature at minimum, and I still get an occasional oscillation in the tracking direction when driven by the Avidyne Trainer XP in the NAV mode. Is there anything else I could tweak to eliminate this?

Thanks! 

Try adjusting your Mixture (either direction slowly) and see if that helps. You should hear the motor smooth out when in the correct mixture. Good Luck..