06/07 ZX14 Headers (no cats), dual Two Bros Carbon Black mufflers, Bazzaz ignition (PCV not available), a flyectomy and the whole lot dialled in on a Dyno by a speed shop.
158hp to 172hp (9% increase)
103ft/lbs to 113ft/lbs (9% increase)
The second attachment shows the AFR, the one with the big dip into rich is the "before". It's a WOT profile, but you can see how it changes to the one above.
The goal of the exhausts was not more power, but sound and aesthetics, but once it was dialled in more power has been a by-product. Have only ridden it to work this morning through traffic so no appreciation yet for how it is running, but the bottom end is much improved as others before me have attested.