Apples to oranges. The intake allowed it to flow better and got more air into the engine.
Take the KR out of the equation. Lets talk old school muscle. 12:1 compression, etc etc. There's no ECU, no KR. Now run 87 octane in it and its going to be at the same or near the same horsepower level on 87 as it is on 100 octane, but it will be knocking like a MF.
Now go put 100 octane back in and the only difference is no knock. Now tell me octane adds horsepower.