its aircraft grade aluminum sprayed with high heat header paint then sprayed with a rubberized semi undercoating. an yes it is the same size as factory piping. an i also upgraded the battery with a large battery.
no the way the box is made it goes right up against the hood so it kinda is pullin in air but not really as much as you think. ima lookin at pipes now since the silencer is off to run chrome piping back down into the finder an ima thinkin should i put a small intake on the pipe so it sucks air up an not dirt an rocks? its got the box around it now so its really not pullin hot air in now. the blue filter is old the red filter is new.