I know what everyone is trying to explain lol. I also think everyone thinks I'm going to go all crazy trying to be a professional porter... which I'm not. All the videos I've watched and threads I've read mainly say to clean up the imperfections in casting and help air flow more efficiently. I know I'm not going to get 300 flow #'s, but this gives me something to do on my car that doesn't cost anything really but time.