Gutted primary cat, overpipe highflow cat midpipe combo ?
 

Greetings,

So, I know I am going Supercharger in the future but for the time being I want to maximize the power with minimum investment. I already have BRZedit and will doing my all stock tune next week to see what I can squeeze out of the FA20 in stock trimmings.

I have been thinking about doing a drop-in filter, gutting the primary cat, and going with the nameless overpipe / midpipe combo with high flow cat and possibly an inexpensive catback (Isis or Q300) or moddified stock catback.

I'm too old for loud anymore or I would go with a single can single exit 2.5" catback to mate with the nameless over / front pipe.

My concerns are:

* Gutting the front cat creates and expansion chamber that will slow the gases down and create back pressure, though i hope it would still net a reduction in back pressure over having the cat in place.

* Using a 2.5" front pipe with stock catback creates a step and more turbulence

Does anyone have any dyno results (virtual or real) or some data logs from a similar setup (drop in, gutted primary cat, nameless over / front combo)??