you can use any size pipe btw 3" and 4" aslong as you use the appropriate connection to the throttle body. A dual filter setup is pretty much pointless along with the ram air and electric fan "Turbos". Just run a simple fenderwell intake or you are wasting your time, money and energy for something that will do absolutely nothing and no one will ever see once it is installed. Ram air only works if there is a straight route to the throttle body with no bends and obviously thats going to be impossible unless you are planning a rwd conversion. lol. The electric superchargers or whatever they are called on ebay these days are an even bigger waste. They dont create any ammount of boost and are completely untunable even if they actually did something.
