back pressure isnt a bad thing... this is why we all dont have a 6'' exhaust on our cars... the expansion slows down velocity and the air cools quicker due to the larger surface area
Its more that when I get ON it, it attracts unwanted attention. It doesnt hurt the ears or anything. The corsas do a good job with the drone. I'll eventually try the twisters or get an expensive evac kit..or inexpensive.