What do you think is a good custom exhaust job?...... im thinking 2" piping?............ What do you think.

2" sounds pretty good, 2 1/4" is the biggest you wanna go on an N/A 4cyl.

Certainly don't need any more than 2".

"2.25 is they typical medium. That's about what most systems for N/A motors are. My A'PEXi WS exhaust as I read and found out actually has "2.36 piping. But "2 - "2.25 should be good enough, don't need bigger that "2.25