Adding wake to existing Submarine Object

[jgnoci@gmail.com]

I am wanting to edit the existing Submarine_Ohio_Class object to add a wake. I have edited the sim.cfg file in the ProgamFiles\...\Sub_Ohio_Class, but whatever I edit in this file seems to have no effect on the rendered image for this object. Please explain if this is the correct way to edit an existing object?
I added the lines:
[Effects]
wake = fx_wake_ss

[mpni]

Hi jgnoci
You right.
In the sim.cfg, be sure there is only one section [Effects].
You have to verify is the "fx_wake_ss.fx" file is present in the Effects folder of P3D.
Otherwise, try with another effect for testing (fx_wake_carrier.fx).
The subbmarine must move for having active effect.
Regards
Michel