Hi guy's new to this forum i have a cbr 400 nc23 rrk 89 model, and it's an on going project nearly finished so since this is the forum for all kinds of answers for this nice little bikes i was wondering what can i do for performance upgrades to my bike.
I also want to ask if a install a stainless steel 4-1 exhaust system will i completely lose my bottom speed? because i really have to rev past 5k to begin to notice the bike pick up speed and i don't want that.

And sorry for my English it's not my native language