im gonna upgrade from a KNN air cleaner to a screaming eagle heavy breather...do i have to change the settings on my fuelpak for it to run better?

 

anytime you add more air, you need to change things

 

I upgraded my K&N to the heavy breather on my nigt train and it ran fine without remapping the PCIII. It was probably already re-mapped when you put the K&N on. The heavy breather dose breeth better but not enough to need to re map. When you start doing other mods like cams, the heavy breather starts to shine.