For sure HotRod Dave you are right on about the tuning but in fact, at the muffler, heat loss gains power. Heat loss brings with it a loss of gas volume and that helps the muffler work a bit easier and this is what you want for good silencing.

Obviously, we are both talking about different ends of the system and I agree about scavenging. Headers and good exhaust systems depend upon it to get fresh air in after getting exhausted air out.

If any others want to see what new cars have on them to get good silencing and performance, check out new Honda and Toyotas. These have split pipes after the axle and run two very large volume mufflers.

Exhaust is such cool science.
Tom