slug420 said:
why cant dual all the way back inprove performance like a bigger single would?
I'd figure it's, assuming your dual pipes have the same diameter as a single, the back pressure is the same. The piping backpressure isn't cummulative, like if you have a 2" single exhaust, the air will go out like 2" piping, now if you have two, 2" pipes, the air will still see only 2" piping, ie, same pressure.
The idea behind dual pipes is for v6 and up engines, because they actualy have two sets of headers, as in a v6, you have a set of 3 pipes on each exhaust headers, the headers on each side converge 3-1 for the most part, and then go out the back, making two pipes out the back. Since four cyls only have one set of headers, there is no point in two exits, it's just like making a maze that has two exits, the hallways are the same size all the time, and you get out of the maze the same speed as if you used the other exit (assuming both exits are identical)
lol I hope I helped some, actualy I hope I confused you
