So I finally got around to removing the resonator and 2nd cat off my exhaust. All I can say is "Perfect". I was hoping for a little better sound, which I got without dumping $600 on a new muffler system that may have sounded too loud. The tone is a little high, but not bad. Warm ups are louder, but once it calms down, you really can't tell until you put your foot on the gas. Highway speeds are basically unnoticeable, no drone. I got a little pop and burble on the down shift. Not over bearing, just right. I'll post before and after sound clips as soon as I have time.

And it's probably my imagination but it feels a little peppier.
Before
https://www.dropbox.com/s/upjadr8rvwvq9pz/OEM.MOV?dl=0

After (Cold Start)
https://www.dropbox.com/s/xf35rr05za...Start.MOV?dl=0

Idle
https://www.dropbox.com/s/oks42qp5n2...armup.MOV?dl=0

What was removed:

 

I like it... Just decided to fabricate a custom muffler delete for mine and the sound is very similar. Either way, great job not spending $600-$1200 just for sound. If you eventually don't like the sound, you can always change later.

Brett

 

Yes. Thank you.

I just picked up a 2014 JCW Countryman and was significant;y disappointed with the exhaust note (or lack of any exhaust note for that matter).

I LOVED my combo of the resonator and cat delete paired with the fJCW exhaust on my R56 and was worried that the Countryman wouldn't be the same with the resonator and cat delete. However it sounds similar!

I was really hoping that I wouldn't have to spend the ~$1000 for an exhaust and then choices are limited because of he rear bumper!

 

I just got the JCW muffler installed my Cooper S, I really like the tone, but want it to be a little louder.

I was thinking either resonator delete, cat delete or both. I am worried about there being a lot of bass noise or boomy drone noise with deleting both of them. Is there a noticeable amount of booming/bassy noise inside the car under acceleration, with both the resonator and cat deleted?

 

It's a little louder, as you would expect, but not much. Cruising down the highway, you'll get more when applying the gas but for the most part it's not bad.

 

Usually removing a cat adds more bass tone to the exhaust that resonates inside the cabin during low rpm acceleration. That's why I am having a tough time deciding between just doing the resonator delete, or just go ahead and delete the cat as well. The bad part about it is that exhaust drone is a personal thing, so what might not be bad for you, might end up being a little too much for me.

Gotta do a trial and error I guess.

 

I was worried about the same thing. That's why I kept what was cut out for about a month. If needed, I would have put the cat and resonator back in. Someone with more smarts than me might be able to validate this but, the Oxygen sensor is on the primary converter located on the down pipe. What I removed was the secondary cat and the resonator.

 

And, before I removed them, when I switched on the sport mode, I had zero pop and burble. nothing, nodda, nill. Now I get what I believe to me a pretty cool down shift pop. My son uses it more than me but you get the idea.

 

Thanks for all the info! And you are right, no O2 sensor in the secondary cat.

 

OK so I took a quick video on my home last night. iPhone sound quality...non-sport mode, not really stepping on it.

https://www.dropbox.com/s/8qqwoqndcs...0Home.MOV?dl=0

 

Bringing this back from the dead....... any updates on this? Still happy? Was interested to hear that the sensors are before this secondary cat and therefore not going to blow any warning lights.

 

The secondary cat is purely for passing emissions, the only O2 sensor that will show a "warning light" is is the one before the 1st cat, in the DP.

Even then, the 1st cat is not a problem as long as you get it cleared with a Manic or RPM flash. MarioKart can handle that, and offers high quality downpipes and other goodies.

Here is my car with MarioKarts turbo and tune. Mine is a 3" DP and custom 3" exhaust with 3 straight through Magnaflow mufflers. I would recommend 2.5" for most people, it also won't be as loud as mine.

 

 

For me the removal of the cat and resonator is good. Not too loud but gives it a little deeper tone. (Hahaha, as much as 4 cylinders can give). and the best part was I didn't have to pay $1000.00 for a new exhaust which I may or may not like. Lets face it, trying to describe a specific tone to someone, is like trying to describe the color red to a blind person. You have to try it for yourself, if you like, keep it, if you don't, go back to the drawing board.

 

 

you can do that but I had the shop weld it up.

 

 

Quick question isn't the factory jcw exhaust 2.75 in? And a upgraded k03/k04 43.5 inch inducer FROM kkk turbos... is that a good exhaust size with a 3in catless dp? I like the factory jcw exhaust but want a louder sound. Resonator remove and 2nd cat should make it much louder?

 

I'm pretty sure the JCW is no bigger than the S, even if it is, it's definitely not 2.75" all the way through. The S is around 2.3" I believe. MarioKart should know more about that.

3" DP is pretty much useless unless you go with a full 3" system. Most MINIs will see no benefit going to a 3" Dp/system.

I've personally ran a 3" DP and 3" exhaust system for the past few years, I'm going back to 2.5" soon.

 

I'm wanting to keep the jcw exhaust just want more sound... the jcw exhaust is good enough. It is a performance exhaust. Spending 500 to 1200 for an exhaust upgrade that only gives maybe 10hp and 10lb-ft of torque to me is not worth it. BUT if I had a regular exhaust is the mcs then upgrading will be worth it.

 

Do what feels best.

I hope you realize this is the R60 area. The R60 JCW vs the S are more different cosmetically than performance.

 

LOL...... great way to describe it. I will be using that one a lot in the future......... well played.

 

oh my bad... not much difference though🤔🤐

 

What pipe did you buy?

 

I am kinda in the same boat, remove the 2nd cat, resonator or both. I already have a catless DP from.mario but want a little more without doing too.much.