Hi guys, I am new here, and I decided it might be helpful to post my personal experience with some of the mods (albeit few) that I have done to my 2011 R56S.

So, one of the first mods I did to my car after owning it for over 3 years, and countless hundreds of hours of deliberation and mind-boxing over whether or not to do the damn thing, was the deletion of the resonator and muffler from my exhaust system.

For around $120 in San Diego, I went to a local muffler shop and had them chop off the resonator and muffler, and in their place stainless steel 2.5" exhaust pipe was welded in to match the rest of the system. It ended up being 3 pieces welded in, as I did not replace the stock Y split before the muffler. There was one piece of pipe to take the place of the resonator, and two pieces for the where the muffler was. A new hanger was created and welded to the new pipes. In total it was around a 1:15 min job and took out $120 out of my wallet.

I just want to say, this is one of the few times in my life where I have never regretted spending money, and I would do it again in a heartbeat. So quickly did my doubt disappear the moment I heard the tone coming from the N18 Prince engine that I honestly couldn't help but smile. I've tried to record the sound on my phone many times, but it never sounds good due to the fact that my phone mic can’t pick up the bass it puts out, and the resulting playback is just tinny sounding. I do however own a studio microphone, and if enough people want to hear it, I could probably be easily convinced to get it outside and record the Mini.

I'll try to describe how it sounds:
If you think that straight piping the mini (after the cats) sounds like any loud obnoxious mustang, charger, or whatever other muscle car on the road, you are completely wrong. This is like, a resonance of the heart. You know, and I really don't believe I am bullshitting here. Everyone I know who has heard the car (including people who know nothing about cars) say it’s clearly louder, but they say it's not an annoying loud, that it sounds nice to listen to. But beyond that, the police officers of San Diego would also attest to it, probably. In the six months I have owned the car, I have been followed by cops (motorcycle and car) closely for over 5-10 minutes, both on the street and on the freeway going 70-85mph, in which they follow me, and it looks like they listen for a bit; they know I am watching them, and in turn I know they are watching me, and then they just leave. It would be a lie to say that I don’t get a mini heart-attack every time this happens (pun-intended), but at this point I've actually stopped caring a bit when an officer is near.

And the exhaust is definitely loud. Oh, it is loud. But never have I been annoyed by it. At over 80mph (my normal freeway commuting speed) I don't really hear anything at all thanks to the Doppler effect. And anytime I am not on the freeway, I get to enjoy some really nice exhaust tones.

So what about the famous burple? Well, it's not a burple anymore. It's more like ... gunshots. Sharp, crisp bangs you can hear consistently, and constantly. My mini always burple'd, incredibly often, and now it’s just incredible. Six months in, the gunshots still entertain me. But once in a while, when driving slow in first/second gear between traffic lights, you can experience this beautiful concoction of a super bass-y burple sound and what I can only describe as the mixture of a gunshot and thunderclap (thundershot?). It starts off with a chain of low sounding burples with a finale of an extraordinarily loud thundershot, that is so audibly stimulating that you enjoy it every time, and it's just the most entertaining thing to watch your passengers and random bystanders jump at because it’s completely unexpected.

Performance feel:
After six months of driving with the exhaust, I can concretely say that with my butt-dyno, the “boost” slingshot effect has moved to around the 2500 mark (so it lost a bit of torque early) but it gained a decent amount of hp/torque in the high end. And I am extraordinarily confident about the last part. Before the modification, hitting 110mph on the freeway felt like the limit of what you might consider “safe”. I’m always been sensitive to the feel of the Mini, and I used to feel the engine begin to “give” a little (for lack of better words to describe it) at 110mph. However, post mod, going 110mph definitely became easier, in fact, it feels just like going 90mph or 100mph. 110mph feels like an absolute breeze now, and that feeling of “give” previously at 110mph now moved to a little past the 120mph mark.
So to sum it up, low end torque dropped a bit as the rpm band went up, but there is a definite noticeable increase in the power at the upper end.



Sorry if this came out a bit like a narrative, but if you have been on the line about doing any type of exhaust mod to the Mini, I really wouldn’t worry about it (unless you are deleting your cats). I decided not to delete them as California (damn CARB) is very final when they want you to not touch the damn cats.

Attached is an image of the muffler being chopped off



Muffler being chopped.


P.S. If someone on these forums drives an all-black JCW in SD, whose license plate has to do with star-wars, that was a great run we had on the 76 a week or so ago. :D

 

Great write up. So you still have the main and secondary cats? How is the drone at 70mph or around 3k-3.5k?

 

Yeah both cats are still there.

The drone at 70mph isnt that bad, although it is louder at 70 than it is at 90, due to the Doppler effect.
Regardless, it did drone a bit at the beginning, and either with time or my mind blocking out the annoying drone parts, I really don't hear it anymore. But the main reason that I don't hear it is that my normal speed on the freeway is always upwards of 80, and at that speed its much less pronounced.

 

I took a recording today, but my phone mic sounds pretty tinny. It is a lot deeper in person, but here it is anyways: