I've heard of people spraying water in the muffler after driving their mustangs around so the muffler will get hot so they can gut the inside of the muffler out to make a better sound? Or spraying some kind of oil or something to brake the walls inside the muffler or something. Wouldn't the water reach the engine and since that's hot. Wouldn't the block crack. I also heard of people drilling holes in the muffler to make the car sound better. I prolly look stupid asking this but does that work? I wouldn't want to try something that will end up messing up my car. Have anyone else heard of this?
Thats a old school trick on glasspacks but it don't work on most mufflers and they have to get really really hot almost glowing hot. My opinion if you can't afford a good sounding muffler then do straight pipe with the cats still on so it isn't real loud but gives you a decent sound. Mine is like that now and it doesn't sound to bad.