Resonance

[S Pack]

Since ive had my highflow cat ive noticed a drone-spot through my exhaust at 2500RPM (louder when cold) thought one of the gaskets had it or i had a leak maybe so i took it back to where i got the cat on.They told me its due to resonance - the vibrations the air makes as it spirally flows through the exhaust pipe.(as they checked for any contact and leaks.)

Does anyone else have this problem and is there a cure apart from restricting my flow and putting a rear resonator on my system.

They also told me my zorst sound sic as in one of the nicest they have heard in a while and i shouldnt change it as i will only hear the resonance while inside the car.(no-one will notice it on the street)

[nsladden]

In my VP S V8 ute i have a 3.5 inch exaust with only one muffler & it sounds sik. I also experience the droning sound. After a while you'll get use to it