There have been all kinds of tests done over the years. A few dynos but more or less it’s been dynos on how much power you loose if you end up locking them in the short runner or gutted.
If you’re considering getting an S6. Most people have realized that you can gut your intake manifold and then get the full JHM ECU / TCU and intake spacers for a fraction of the cost of the new intake manifold and the JHM tune will give you a handsom amount of power well over what you’d loose with the non fully functional intake.