Hey man, thanks for reply.
Unfortunately, that didn't solve the problem :(
I checked before all .ini files that have "blow-off valve" in it, but made no progress.
Perhaps I'm going the wrong way?
I noticed some tiny bugs in game after installing some addons like RSRBR 2010 and CamHack, but not sure why would affect this.
Some cars have blow-off sound, some don't...
I must admit I'm confused...
Any help is welcome
Thanks