I am makeing a after market exhuast from my stock one any tips?

the bike is a 2005 kawasaki z750s ok here is what I have done so far I cut 6 inchs off the can to make it shorter and more sportyer looking I took out all the guts till just the alloy shell was left took it off tac welded and peice of 2 in stainless stell pipe to the inside and then but a baffle in which I turned around so the fins dont catch as much flow which makes it louder ( the louder the better) but now I am going to take it apart and weld caps to the front and back of the baffle so all the air goes into the baffle and not around the outside. I dont think I have enough back presure but the bike runs fine othere then in higher r's it doesnt seam to pick up as quick ( i know a re map is needed) as I left off the gas it gets that popping sound like older trucks do as they go down over a hill if you know what I mean so if any one can give me tips on what I can do to improve this experiment I would appericate it and if you wanna chat message me

A K&N will only make it pop more. It is lean. Jet the carbs. Quit being so cheap and go buy a good exhaust.