Restrictive Mufflers

Cut away of some 2 1/2" dynomax super turbos. Offset in/center out. The inside tubes are a choking 2 1/4". And notice how the air has to fight to get around that center-out tube when it makes that first turn? The offset in/offset out super turbos are much better but you will need custom tail pipes to run those. I ripped these off my car and went with 2 1/2" ultra flows, I don't see much of a difference in noise, but the bump in power feels substantial and the car idles way better.