Originally Posted by Boxer4PSI
...With the muffler angled, it provides the straightest line possible for exhaust flow to travel out of my car from the turbo. The more bends you have (regardless of whether u have mandrel bent pipes or not) the more u slow down the exhaust flow, which is restricting the exhaust more.
Thats what I've always thought was the reasoning behind it. A whole bunch of 90 degree bends may look clean with the exhuast coming straightout, but its still a performance hinderance.