Well, once I saw on youtube video where driver used real blow-off sound, not sure is it possible with .eng file, must be some external application. Personaly I don't need any change in sound, default are best for me
it does, you can change the single bang that the whole engine sound is synthesized from. But it has to be in a special format, easiest to find out by exporting the stock wav file from the Shift-A menu.