@wahan
Yes it does improves the performance but keeping in mind that it will also increae ur consumption too
Explaination:
As there will be no distortion in air passage from the engine to the cylincer it will increase ur initials hence increasing ur performance pickup......
Using ur stock exhaust with free flow will help in producing less noise but installing after market exhaust will also increae ur sound........
Depending on wht u need sound or just pickup....
Suggestions:
Before going for a free flow i wld recomend u to get ur sparl plugs changes get NGK Bpr5egp best for khyber's engine
get plug wires 8mm orignal
get ur coil changes to0
m sure u wont need free flow......