Agree! There can be a big difference in cfm with a straight through muffler vs a chambered or turbo type muffler especially if you are racing the car and trying to get every single HP you can possibly get.
That being said, for everyone reading, the pipes have a much greater affect on the exhaust systems performance than the mufflers do regardless of what mufflers are chosen..... well I mean short of putting a cork in there! :lol: