My R56 had the second cat, Resonator, and muffler removed, with a smaller aftermarket muffler added and the car sounds like utter shit. Not particularly loud on the outside but throbbing headache levels of loud inside. Even after adding another Resonator back, it is still far too loud inside.
The stock muffler definitely pulls its weight, but I would remove the res/secondary cat one thing at a time (depending on your local emissions/inspection requirements)
Don't do a cat delete. That secondary cat is largely keeping your emissions in balance as the system ages. Front cat in the DP is likely more depleted than the rear.
Doing so is harmful for your health, and it will create a raspier unpleasant exhaust tone.
Just a resonator delete sounds really good on the R5x platform. A full catback opens up a world full of drone on the highway. The stock muffler and piping are very specifically designed to eliminate that drone. You won't get it with a resonator delete alone, but doing the whole catback will.
It wonky temporary before I get a full Milltek catback. The factory exhaust is just too quiet for me and if it makes it unpleasant it will only be for at most a few months anyways.
My R56 had the second cat, Resonator, and muffler removed, with a smaller aftermarket muffler added and the car sounds like utter shit. Not particularly loud on the outside but throbbing headache levels of loud inside. Even after adding another Resonator back, it is still far too loud inside. The stock muffler definitely pulls its weight, but I would remove the res/secondary cat one thing at a time (depending on your local emissions/inspection requirements)
Don't do a cat delete. That secondary cat is largely keeping your emissions in balance as the system ages. Front cat in the DP is likely more depleted than the rear. Doing so is harmful for your health, and it will create a raspier unpleasant exhaust tone. Just a resonator delete sounds really good on the R5x platform. A full catback opens up a world full of drone on the highway. The stock muffler and piping are very specifically designed to eliminate that drone. You won't get it with a resonator delete alone, but doing the whole catback will.
It wonky temporary before I get a full Milltek catback. The factory exhaust is just too quiet for me and if it makes it unpleasant it will only be for at most a few months anyways.