X-Pipe problem for E92 M3

[burakkose]

I recently purchased Kreissieg for my E92 M3, without the x pipe. I will keep the primary cats but remove secondary cats and resonators, like Kreissieg's x-pipe.

We don't have Challenge etc. here so our exhaust guy will build this x-pipe for me. I want the exhaust to bleed out!

So I'm gonna need some technical knowledge as well as experience.

The Kreissieg uses 60mm diameter pipes for x pipe. which is around 2.36in

About the design of the x pipe, I am stuck in between IPE F1 type with a hole in the merge section or the Kreissieg type.
Any ideas which would be louder and why?

the ipe f1 x pipe is in below pic (right side bottom)


and this is kreissieg's