the pipe comes to a knife edge inside and if you look down each tube you can see the full opening of each pipe. Half of exaust from each tube will split down each of the exit tubes. This design should cause a better scavenging effect. The exaust cannot cross each other inside to exit the opposite side tube because the velosity is too great. Take a look at the stillen or B&B X pipe the exaust is really staying mostly on the side it came from and mixing slightly in the middle. Also if you do the math A single 3" pipe flows more then two 2 1/4" pipes. two 2 1/2" pipes flow around the same as one 3 1/2" pipe. I forget the formula But I remember doing the math for every differant configuration possible. I will try to get a picture up soon of what the inside looks like.
