I recently installed a BHR midpipe on my 8 and I thought came to mind. Do our 8s have greater horsepower without the mufflers and exhaust and just the midpipe or does our exhaust with the back pressure from the mufflers have more power? And yes I'm very aware of the loudness of my car, when installing the midpipe I started the car and revved it with nothing but headers...holy **** it was wonderful 😂

 

Exhaust mods (unless you consider a turbo an exhaust mod) do nothing for power. And running without mufflers will get you punched in the face.

 

The midpipe you just installed nets you a few ponies. That is pretty much all that is to be had from exhaust mods unless you go to a header (preferably long tube), which then creates problems with engine compartment heat unless you get creative with heat shielding. And a header is also only worth a few HP. The real exhaust restriction is in the ports in the engine. You can have it ported for additional small gains, but there isn't much to be had there either. The muffler itself does not present much of a restriction.