I'm building up an all motor b16 for a daily driver. I want to put ctr pistons, header, and regular bolt ons. I need to know what size or kind of exhaust would be good for this setup. Like an Apexi N1 or what? What size piping? details wou ld help please

 

i would just stick with an apex n1 its 60mm (2 1/2 inch) piping whcih is good for all motor street application

 

2 1/2 is just about pushing it, especially for a 1.6L NA motor running street RPM. BTW, 60mm is 2.36". The cat-back exhaust section is not all that important other than diameter, the header and collector primarily set power output and engine behavior. Choose whichever you like the looks and sound of the best, so long as it's not ANY larger than 2.5". Personally I'd opt for something as close to 2.25" as possible.