4" cai?
hammer and weed say 4" is a waste, I believe them. Unless you have some other crazy mods, i don't think its worth it. Buy one from weed if he is still selling them and you have the money, or make one like mine, I think it's a pretty good setup.
I made mine out of 3 1/2" aluminum tubing. I don't have a pic of it, but I made it run below the radiator in the open space in the front bumper. Over by the passengers side wheel well. Just remember if you make one yourself, CLEAN IT OUT THOROUGHLY before putting it on.



