After driving the elco for 5 yrs with flowmasters (weekends,holidays) I couldn't take the droning anymore so I went to a flowmaster dealer, he asked if I had a H pipe in the system -- NO -- So we put one in and what a difference. I'll bet its 50% quieter. I have to say I loved the sound just driving thru a parking lot before but it wasn't worth the droning. Now I have to get use to the new sound.. The dealer also tells me as a side benefit I should get more mid range torque