Not exactly Larinis

[CatmanV2]

True, but cross sectional area is not the only factor. Drag at the edges has a significant impact on flow.

C

 

[maverick]

I think the main issue is noise and not the extra few bhp gained which in the real world you wouldn't be able to tell , after completely de baffling my system apart from the primary cats it still sounded very farty I put this down to letting air out of a ballon syndrome if you get what I mean , I think this is why the Larini system sounds more Basie

 

[mjheathcote]

I don't have an issue with your increased cross sectional area, its just not very elegant.
The cross sectional area of the original squashed pipes I think you have underestimated. I have measured this myself, but don't have the measurements to hand, think was more like 19 squ.cm
Also are you sure larini use such small diameter pipes?