What size should I make my custom b-pipe? I am installing a cherry bomb glass-pack instead of the large resonator that is stock, and I will be keeping my stock mufflers. I am thinking 2.25" is enough, but maybe it should be 2.5". What do you guys think?

 

@ cherry bomb. But, it's your choice.

My cat back is 2.5" to custom resonator to 2.25" all the way back.

CleanCL is 2.5" all the way back with custom resonator and mufflers

 

I have decided to go 2.25" from the cat to the resonator. I'll try and do the same all the way to the Y-pipe.