Which would be better for a cobalt that wil be getting turbo installed in it later on next year? Im thinking about getting a 2.5 inch dual exhaust or single 3 inch exhaust but aint sure which will be better for performance and everything overall. If any1 has any info plz help out...

 

I would think a 3'' single exhaust would be better.

 

Dual exhaust on a 4cyl in-line engine is pointless...it's only for looks. Turbo cars want very little back pressure so 3" is the way to go.

 

second that