Originally Posted by LZH

Jim - so CLEARLY something is functioning differently during cold start up...do you know what it is ??? I mean, during cold start at 1000 rpms the exhaust note is amazing. Then when the idle lowers and I use the gas pedal to maintain 1000rpms, the sound is mundane and crappy - SO WHAT GIVES>>?? Sounds to me like the mufflers have a butterfly valve but I've never really looked at them very closely...wonder if there is a air line (vacuum line) going into the muffler??