Okay, so I strengthened files for ground roll, turbulence, ground bumps and engine. Note that the ground roll file is relatively smooth but strong…like for asphalt runways. I also have a file for concrete runways but I was unconvinced by it so I left it out. Zip file is attached. Unzip the contents into your Documents\SimShaker Sound Module samples\Customized\1
Your mileage may vary.
Here’s my (current) settings:
