I have the Greddy Evo II exhaust w/ a test pipe and the other day when i looked in my muffler i seen these little wire strings coming up so i started pulling them out. I guess its some kinda sound deadener. Im trying to make my exhaust flow a little better so im wondering if anyone ever hollowed out a muffler? I dont have a cat so im guessing this will improve exhaust flow a little bit more. Is this possible?