Exhaust mod DIY sounds way better

[RevEngineer99 130]

Did you not read my post above #18? Read it and see if this what is taking place. Later RJD

If you read my post (#15), it explains what you posted in #18.

 

[aceinspp99 130]

If you read my post (#15), it explains what you posted in #18.

I was making a point that this what you have and you did not mention this was an option on your car. Later RJD

 

[Ares490 19]

I’ve been under the car a couple of times. There are no active exhaust valves. The exhaust is loud on start up, my best guess is the ignition timing is retarded quite a bit during warm up to get the cats up to temperature as fast as possible and the turbo waste gates are likely wide open too. After a minute or two, the exhaust suddenly quiets down and the idle speed settles gradually. Almost sounds like a valve closing but it’s not.

Yeah the Scat Pack does the same thing you're talking about. I had assumed part of the volume change was the exhaust valves, but the majority of it is definitely just engine behavior. In cold weather it's crazy loud until it warms a bit.
I didn't think about the waste gates affecting idle exhaust sounds. It's a good theory I'll listen for. Might be more apparent once I get an aftermarket intake