A muffler delete has f-all to do with the turbo... it's the part of the exhaust under the car... aka the boxes that you can see when you look under it, not to be confused with the cat or dpf filters (which look like mufflers).. what you are looking for is the downpipe to mate up with the exhaust system... best practise is to get a better flowing one usually in a bigger diameter than the oem pipe on your B7. I suggest you talk to a tuner(remapper) about what would be the right size as they can tell you what works from daily experience. And what would be a problem or not (think MOT's etc)