Personally not in a rush to change out the exhaust on the new 16/ZX14,aside from the fact the stock is God awful ugly...on previous bikes when you change exhausts a lean condition and poor performance,less torque accompany the change unless you get a tune. It would run like a scalded dog at full throttle but otherwise blow white lean smoke out the tail pipe and have a tendency to fall on it's face ...my question is does a more open exhaust hurt performance as a stand alone change or does it increase H/P, without a tune.