here are t3h pics!
so there it is. pipes are 3 inches all the way to the TB except for the "accordion section." I needed something to connect the pipes to the airbox with so I chopped out a piece from another 2.2l intake I had sitting around. ideally that piece would be another 3 inch ABS pipe.
you can see the little tube in the last pic the little pipe that goes from the box into the fender. this is important to install or else you'll be pulling in air from teh fender, AND ari from around the sides of the box. not only will this be giving you warmer air, but the two streams will meet just before the box and cause turbulence.
so there she is in a nutshell. much like an injen or an AEM intake that feeds from teh fender instead of the engine bay. also, I think it's a little wider.
PS - check out the snazzy strut top hat covers. while you're in the junkyard getting this or that, look at the older legacies. some of them have those and I think they look nice on Imprezas.