Post by
fyarf »
https://forums.nicoclub.com/fyarf-u259099.html
Mon Apr 11, 2016 9:57 am
Check the other thread, do what you think will work best for you, I can't decide that, but I can say 2.5" will work with airflow efficiency better than 2.25", but don't go over 3". Speak with your installer and see what his experience leads him to believe.
Again, replace the midpipe completely. Lose the faux resonator.