3 Inch or 2.5 Inch TTI tailpipes ??

I donnnooo, Joe I have trouble rapping my head around this. IF this is true, then why do open headers work? Why would we not restrict them "down some" and with more length? And yes, I do know about header extensions, and I know about the "old school" way of checking them for temperature.

my car ran exactly the same at the track through the full exhaust as it did with the cut outs open..