Burtec, I purchased the extra loud TOR long pipes.Great Bay Triumph sells em.When I first put em on I got that pop-pop-pop also.I really did not care for the sound at idle. But after putting on a 125 miles or so, that sound has just about gone.They are getting a lot deeper at idle,and getting pretty darn loud when accelerating.Basically just about what I wanted.If they get much louder though, I may have a problem with our motor patrol rolling tax collectors. : Al