hi all expert here,

may i ask,wat the ideal piping size for proton persona.how if i oni change the extractor(4-2-1),mid box n s type muffler but use bek stock piping?but heard my fren i cant gain much power from my exhaust system if i do so.
all i need is nice pick-up power due to campro bad pick up pow but got high end power oni(stock).i do not nd much high end pow since my stock can go 140km/h for 3rd gear .nd my car be better pick up n maintain current high end power

hope all sifu here can help

haiz....headache bought a muffler tanabe G-power medallion for my proton persona but cant fix in.so welding bek the oem 1.