I know this question has been asked thousands of times and trust me I have read through almost every thread I could find on this topic, but I am still a bit confused at the end.

I just installed a JCW muffler on my 13 MCcS, I really like the tone of the exhaust, but want to make it slightly louder without introducing a lot of boomy/bass filled drone.

I have seen lots of threads where people are either deleting the resonator or deleting both the secondary cat and resonator. I am trying to see if it just makes sense to remove both the cat and resonator and get that little performance bump from having no cat. But, worried that this would result in heavy bass type noise in the cabin during acceleration.

Anyone who was in a similar situation, please chime in.

 

I just deleted both res/cat but i have an oem S exhaust. I wouldnt say boomy but more on the throatier side. I still cant hear my exhaust with music playing though.

 

I had a 135i before, I did not like it when I removed the 2nd cat and resonator. So this time around I want to keep atleast one. Which one do you think will have a bigger affect on drone and exhaust volume, delete 2nd cat, but keep resonator or delete resonator and keep 2nd cat?

 

I'd say take both off. I really can't hear the car unless my Windows are down. I drive with the music on mute and cracked Windows just to hear my pops and crackles. It's really not bad at all. I was kind of disappointed on how quiet it was. Now it might be annoying with a catless downpipe and a cut/res

 

You still have the stock muffler on the car though, that keeps it pretty quiet. I installed the JCW muffler and that's why I am worried haha. If I kept the stock muffler, I definitely would have deleted the cat and resonator.

 

I went ahead and just deleted the resonator and left the second cat on. My recommendation for anyone doing a JCW muffler install on a MCS, do yourself a favor and get the resonator deleted at the same time, it makes a huge difference! It really brings out the tone of the JCW muffler and gives you a bit more volume, without adding any noticeable amount of drone.

You can choose to also delete the secondary cat for a slight gain in HP, but it alters the tone to a more deeper growl that has a more bass like sound at lower RPM. I prefer the high pitch mechanical sound that BMW M cars usually have, so the resonator delete did just what i was looking for.