I can definately tell a difference with my SOTP (Seat Of The Pants) Dyno. Seems to add alot more torque throughout. Sounds really awsome. I'm really curious to see how it does against my built Z. The Z seems to have a much bigger hit to it but until I get them side by side it's hard to tell. Of course the Z has quite a few engine mods so it should have a nice hit.\
Of course I still have to get the PIM and FIMAK so I can dial it in to maximize the mods on it right now. I know Yoshi says they have the maps already in the PIM for the full Yoshi exhaust but that's for their elivation and temps at the time they created them. There is always room for improvement depending on many factors.