Ok, I know there are dozens of exhaust threads on here, and I have searched through them for hours. I have read countless posts and watched just about every R56 exhaust video on youtube. However, I have yet to find one that answers my question.....so here goes.

I have a 2009 MCS, I live in CA, I can't remove my downpipe or 2nd cat, and I hate drone. I would like to have a custom 2.5" exhaust made at some point with a Magnaflow resonator and muffler, but it seems no one has ever done this before. I know there are members on here who have chopped off the stock muffler and replaced it with a Magnaflow, but it droned. There are many others who have chopped off everything from the flexpipe back, welded in pipe, and thrown a Magnaflow on the back, but they also drone.

I know which Magnaflow muffler I want (2.5" inlet - dual 2.25" outlet), but I'd like to know which Magnaflow resonator (or any resonator for that matter) to use. The JCW's resonator takes up almost two feet of pipe before that crossbrace thing. Is that a good indicator of the size resonator I would need?

I'd greatly appreciate the help! Thanks!

 

If you want to run stock DP > Stock 2nd Cat > Magnaflow Resonator > Magnaflow Muffler > Tips
chances are it will still Drone.
I don't see going stock everything to the Magnaflow muffler droning though. The owner may have a different perception of what "drone" is, but changing just the rear muffler allows little to no room for drone to create, as drone is created from the "sound waves" / "vibrations" in the exhaust being at resonance, which, when changing just the rear muffler, is almost impossible with stock piping/resonators. What people probably are hearing is the increased noise the exhaust is creating by having a more open muffler. The noise you hear out the back of the car is the exhaust. If you hear noise that sounds like its originating from every corner inside of your car and is driving you crazy, thats drone. Look up some videos on youtube to see what drone sounds like in different cars. It doesn't only happen at highway speeds, as its dependent on RPM. If I let off my throttle at 3-3.5k, the drone is obnoxious and you cannot hear yourself talk sometimes. I control my drone by my throttle position (eg. if cruising I keep about 15-20% throttle on the highway as it cancels out 90% of my exhaust noise at that position). In the city, I don't mind it so much.

If you want an exhaust without drone thats not stock, and not JCW, look into a miltek. They are quieter by far, but they are much more refined and don't have drone.

FYI, I have a 2.5" custom magnaflow- just piping from the flex pipe back to the magnaflow muffler. No resonator, no 2nd cat. Its loud.
If you keep your 2nd cat, it will tone down the noise a lot.
Another suggestion, if you're keeping the 2nd cat, You could probably go with stock size piping (or even keep stock piping), as the restriction from having the extra cat will give you little to no performance gains as the exhaust will not be anymore freeflowing. Having ~.2 inch more exhaust after the 2nd cat will only increase noise, and possibility of drone.

Keep in mind also, that since drone relates to the frequency of the sound waves, oscillating at resonance (think actual waves oscillating up and down), the material and thickness (gauge) of your exhaust piping will also make a large difference. In such, a thicker gauge pipe may help reduce tinny sounds and possibly resonance too. You'd have to look further into that as I cannot say it will help or not.

 

Sorry, just to actually answer your question, theres a thread called help magnaflow muffler or something of the like that I posted at with my resonator choice and a discussion abotu it. I'm at work so I don't know the model I chose, but its about 20 or 22" long I forget which.

When you said the JCW resonator is before the brace is that between the cat and brace or the brace and muffler in the rear of the car? I'd like to get an idea of where OEM puts it vs where I can be welding mine in. I know stock S exhaust resonator is between the cat and brace, so I'm assuming the jcw is the same.

 

I almost have your setup... i have kept everything stock cept the 2.5 inch piping muffler and tips from magnaflo after the oem resonator and 2nd cat. I remembered praying that this setup would not drone and for the first few weeks, it did horribly. As it "settled" the drone became less noticeable and so did the volume overall (either that or im becoming more deaf). I too at some point was looking at aftermarket resonators. All I can suggest is that the position of the resonator and the overall length will change the sound. Its going to take a lot of patience to find the right length of resonator and location....

 

You might have to go to a 3" system. I would ask Dave at DDMWorks about his catback. He has a version that connects after the 2nd cat with a Magnaflow muffler.

 

If it drones in a 2.5 inch system, the same setup will drone on a 3 inch system, just at a different frequency (RPM). It will be worse too, amplitude of the sound wave at resonance will be much larger as it has more space to work with. How bad it is depends on the exact frequency of the resonance.

I'm with BostonR56S, I find it hard to believe that people who lopped off the stock mufflers and replaced them with Magnaflows have "drone". Even with my resonator cut out, a Y pipe, and Magnaflows, drone is almost non-existent.

 

Right, my audi a6 had 2.25" piping and I swapped out the muffler for a magnaflow, and removed a large stock resonator, left all stock piping. No drone what-so-ever, yet an improved exhaust note. Check my youtube (akakong) (i cannot access it at work right now), and its one of the earlier videos. You'll also find my magnaflow vids for my MINI.

Pillar, were you referring to me about the same setup? I'm 2.5" from the DP back to the muffler. No 2nd cat, no resonator.
It sounds like you changed the piping after the resonator. The increase in piping size after a restricted spot can cause sound waves to act funny, as volume increases and material changes, such resonance within that new piping can and probably is occuring. That frequency at which its resonating (at your specific rpm range) is whats causing the drone in your compartment. You could possibly try a longer (more gradual) adapter piece, going from 2.35" (or whatever stock is) to 2.5" sleeve, so that the transfer is not so abrupt.

 

This perhaps not even an issue for you, but when I switched from the stock MCS to JCW Stage 1 exhaust there was a noticable drone (I've heard that the stock JCW exhaust is considerably quieter than the Stage 1). Regardless, I used to drive around with my rear seats down and one day I put them up and even put the boot hatch cover lid on. Wow what a difference! Huge drone improvement. I don't know if that's your habbit as well, if so just put your rear seats. Duh why didn't I think of that in the first place?

 

was referring to op...
that may not be a bad idea... but as of now, I dont mind the drone. I think its on and off depending on ambient temp and warm up

 

Hey everyone, sorry to start the thread and then go MIA. Thanks for all the tips. I guess when the time comes, I'll just have to do a little trial and error. BostonR56S, if you ever get around to adding that resonator, I'm sure we'd all love a report on any difference it makes.

Ya know, more than anything, I just want the "pop and burble" of the JCW. I don't even really care about more power. The loud pops my friend's JCW gets between shifts is just so damn cool. Every other country gets only one cat and the "pop and burble" on the 172hp MCS. We got hosed.

 

Oddly enough, my stock 2010 MCSa produces a ton of drone at certain rpms. As BostonR56S described above I can control it via throttle. I find it often very annoying. Wish I could tone it down.

 

cenobyt, i highly doubt you're getting drone with a stock exhaust... if so you can consider it defective (or a leak) and get it fixed under warranty. More likely though, is that you're thinking of a sportier exhaust being 'drone'. Drone is not simply the exhaust being loud or the car being loud, its a resonating frequency that vibrates in your car and causes you not to hear or be able to talk if loud enough.

 

Yup, I think I have drone. It, as you said, may be an exhaust leak. Under normal conditions it's ok, sounds like a sporty exhaust. At certain throttle positions it just creates this "ddddrrrroooonnnneeeee".

With the back seats down, you want to rip your ears off your head to make it stop.

In Boston, there are plenty of crap roads and pot holes, maybe I hit something hard and loosened something up.

 

Ah, didn't even notice you're from Boston! Nice, but yeah, I'd get that checked out. Its possible you hit the oem v-band clamp on a pot hole, as that sits pretty low. If youknocked it pretty good on a pothole it very well could have knocked your dp to exhaust piping apart to a leak, or, possibly your flex pipe has a leak if all those pothole have ripped your exhaust hangers (i know one of mine are partially ripped, and i wouldnt be surprised if it was from all the potholes bouncing the car around).
Are you lowered? Any other mods?

AND *************update***********
I welded up my resonator finally last night after a year and a half of having it sitting in my room. WOW ,does it make a difference. the 3-4k rpm drone is gone. It may still SLIGHTLY be there as a hint in the background, but compared to what I had before, its night and day. WOT the car is still loud as it was, which I love, but under normal driving now, theres no crazy "echo" drone inside the cabin anymore. Its MUCH more tolerable.
Next on the list is an exhaust cutout right after the DP =D muhwaha

 

yup. it was an exhaust leak. thanks!

no good mods yet. strut bar, alta antenna, heat shield. Saving up for a tune and a DOS intake.

 

BostonR56S, any chance for some updated vids with the resonator added? Now that you've added it, you've completed what I envision doing (except I'll have the 2nd cat). Glad to hear the resonator made a world of difference.

I used to have a 1973 Ford Bronco with 3" exhaust and 40 series Flowmasters. It was loud as hell and I loved it, but the drone was brutal. I swore I would never have anything that droned like that again if I could avoid it.

 

Ceno, that's awesome news. It was probably the v band that was loose I'm assuming?

Mr Burns, I will try to get something recorded when I get my car back from the dealer in a wrek. until then I'm in a justacoop. To be honest, being excited of having a resanotor on, I didn't think about the properties of a muffler/resonator. As it goes through heat cycles etc, the materials inside the muffler become packed and settled. Usually, making it a bit louder. Thus, a little drone is back, but it is still a huge noticeable difference, as u can manage the slight drone at 3k rpm whereas before its hard to hear. I'm not even sure if I'd classify it as drone anymore either. It's really only when accellerating >40% throttle that it causes a resonance. At cruise now its quiet compared to the drone before. Sorry, typing on phone.. ill update more later.

 

I have Stock DP - > No Cat custom midpipe - > Alta 3" and Alta resonator and muffler
I get no drone at all at any speed and i picked up 15-20hp off that exhaust change at higher rpms

 

That's awesome, malteseracer! Unfortunately, I live in CA, and CA invented the CARB state so I have to keep my 2nd cat.

 

15-20 hp, is that dyno verified from pre and post install of the exhaust?
I only ask because I doubt you're seeing 15-20hp from just an exhaust with no tune to accompany it. The stock ecu wouldn't allow for it as a straight bolt on.
Even if 15-20 is crank hp, thats still 13-17whp gain. If you did, that'd be pretty awseome, i'd like to see dyno graphs for it. In addition, you'd prob be the first MINI without a tune to get increases like that from an exhaust alone.

Or, thats a manufacturers claim, which = marketing bs

 

Or at an rpm range you will never use, and less at lower RPM where you do use it. In other words just a number, even if a valid dyno number by itself, is meaningless

Now, explain why the very same increase could not be achieved by changing the waste gate programming. This is a TURBO. You have more options that in a NA engine.

 

Thats just a personal estimate and probably an exaggeration but the power gain from the not cat midpipe in itself had to be 10hp to the wheels after about 4k rpm. You can actually feel the difference and my friends TL Type S who used to peace out after like 100mph needs a lot more to get away from me now. The gain up top is ridiculous.

 

dyno of a stock R56S vs my R56S (with intake, exhaust with basically a straight pipe from the dp back, no tune at the time), was 170whp, 190 wtq vs my 172 whp, 193 wtq. So, there were minimal differences. They were run on the dyno right after one another. Others with exhausts and no tunes also ran about the same. When I dynoed again (at a tune party) with a tune, exhaust, intake, vs another mini with the same tune and jcw exhaust, I put out almost 10 wtq over him. So thats where the difference really was shown.
I know this thread was old, but thought i'd respond to this since I never saw it months ago, and also an update to my exhaust setup

The resonator I put on a few months back has fully settled in/broken in, and to be blunt, the drones back. Once the materials within the resonator all packed down with the heat cycles, its essentially acting like a straight pipe again. With my 70 mile daily commute, its getting a bit annoying.

My idea is to throw the stock piping back in between the flex pipe and the magnaflow muffler in the rear (thus essentially bringing it back to stock besides the muffler itself). This'll kill 90% of the aftermarket noise, but will still have the nice looking tips in the rear with a bit sportier of a sound (nothing performance here).

Then, between the flex pipe and stock piping that i'll put back in, I'll weld in an electronic cutout. Put some piping up to that and possibly run it to a side exit exhaust. This way when I'm commuting I can leave it at stock, but when I want to have my fun/need the extra power, flip the switch inside the car and basically have a straight pipe from my DP out. Ideas about this??

 

If you hate drone you don't want an aftermarket exhaust.

 

Sorry, i disagree. Not all aftermarket exhausts drone. Put a miltek on and see if it drones. They dont, but they do cost an arm, compared to my custom setup. I was out the door for under $350 installed with parts on my custom setup, and I loved the sound, and did not have a problem with the loudness/drone. Had it for 2 years through college like this, and it was great. But now with a 70 mile commute to work everyday, cruising at 80-85, it can start bothering me. The gf also wants to kill me anytime we go on a trip. So not to say I hate drone, its more I'd like an alternative solution for getting the sound and power advantages when I want it, not 24/7. If I hated drone, I wouldn't get an aftermarket exhaust, you're right. If I had the money, I'd have a seperate car for my daily driver, or this would be a daily driver and I'd have a nicer car for my weekend car- in which case the MINI wouldn't be modded the way it is now. But, im a poor college grad in debt working as an engineer. Maybe in 10 years it'll be a different story.