Engine/exhaust sound based on the setup.

[Venom]

Of course you won't hear turbo sound when you don't have a turbo installed.. I was talking about sound difference between turbo levels. Turbo sound depends on how much boost there is before you let off the gas, if there's upshift when the boost hasn't reached maximum, you hear the shorter sound, if the boost is full, you hear the longer sound.
Well, you mentioned bad transmission when talking about SGT.