I have just came across this amazing simulated sound engine for most piston engine.
Sounds pretty good imho and the source is there for curious.
It might be too much CPU dependent for LFS but currently it is ahead!
https://youtu.be/WPCMNnM6D0k
https://github.com/ange-yaghi/engine-sim
https://www.engine-sim.parts/

very nice indeed !

it not just might be too CPU heavy for LFS. It definitely is off the scales too cpu heavy for LFS. One engine with 10 cylinders is enough to tax a ryzen 7.

It's probably better if the devs focus on improving the current sound system instead when the time comes.

Quote from fatalunfair :

https://www.lfs.net/forum/thread/99919-Finally-a-good-engine-sound-simulator%3F-%28open-source%29

Woops I am out of fashion sorry...

And no I am not telling Scawen what he should he focus on...
But maybe some day by looking at it, some addition to current sound model would pop up for the better...

I'm wondering if this could be implemented externally somehow with OutSim / OutGauge..

Quote from Nadeo4441 :

I'm wondering if this could be implemented externally somehow with OutSim / OutGauge..

That's not out of the question. The engine sim have a built in RPM holder constraint.
If this RPM constraint was made to update in realtime based on your outgauge RPM and control the engine sim throttle via your LFS throttle you could actually run it externally.

But it would only work for your own personal vehicle of course.