So a good "closed" system is as good as the cut-outs, basically. Do you feel or have you tested any of the exhaust systems you have had to get actual power results? I am so tempted to do exhaust work but from what I have read there is little to be gained from a $1000. system. I have a system planned. PYPES cats for forced induction vehicles, an x-pipe instead of the H it has, resonator delete and a BORLA muffler as they have no drone and make good low end torque. Finding exhaust pipes to use is where I am having a hard time, know a good source that is not $800.? 2.25" would likely be fine if needed to keep velocity up to help scavenging.Thanks for the experience!