Jerry, I guessing these test are done with your #19?  Maybe I am not seeing things correctly, But looking at the first graph (Green and Red) the Red with P/V open and was making more Bottom end and good Mid and then signs of sharply, Then I think Mat was correct on that he stated more bottom end with more spring tension, But now I understand from your graphs is you need to be in both worlds, have the correct spring tension to take full advantage of the power band of any P/V quad with a performance exhaust, Any chance you could have someone with your guidance take a video to show the correct adjustment to power valve and RPM, maybe bug Dale?   Again Thank you for the Info.