I love the sound of my Borlas I just cant stand the interior noise its just very annoying to me because of the resonator delete when its so loud I have to turn up my radio over the sound of the exhaust to hear it. This happens whenever I shift and put put a decent foot into the throttle which is needed for everyday driving. Maybe I am not used to it . I think its just a personal preference on the interior noise level that your comfortable with while driving.How annoying is having no resonator? I know someone who took his off of his speed3 and it really isnt annoying or any louder just more of a rumble to it.
I want to do a custom exhaust like they did with the 2.5" piping all the way through with no resonators but I want 2 Borla mufflers instead any input what size piping will be better the stock or increasing it to 2.5" and would they also be able to make a custom downpipe since thats where the power really comes from and the rest is more noise related?
As for the piping I would stick to stock size 2.25. From what I read there is an exact science to it for the stock size to be best for best performance.
......That is unless like OZ said you get someplace to make custom headers then u can possibly consider 2.5 but I would go no bigger on that route.
Anyways hope this helps out.