I'm eyeing the Competition Evo (part # 71160CKR): https://www.arrow.it/en/assembled/1502/Suzuki-GSX-R-1000---1000-R-2017 on Revzilla, they explicitly call out the 71160CKZ (non-Evo) as needing to be tuned but the Arrow page shows the tube being larger for the CKR. The CKR is more expensive too. (Note: I was going to get the bike tuned regardless of which one was bought). In short, what gives? I feel like I'm missing something here.
I saw that on the link and even pointed that out! I was looking more for: "With the Evo having a bigger pipe, less back-pressure and more HP/Torque. Revzilla is just being odd in their wording because both would need to be tuned in order to properly realize their potential and avoid running lean and poor throttle response in the low-end"
When I was researching between the two systems for my zx10r arrow told me that the systems with the 65mm midpipe are better suited for built sbk engines and the 60 is for tuned/mildly built superstock engines.
What would constitute an upgrade for these engines? Is that new cams, bored out even larger, or something as simple as derestricting the throttle blades (which I did do)?