A few weeks ago when I was visiting the local Mini dealership, they had just received the brand new 2009 JCW. Then I saw someone took it for a test drive and it had a distinctive popping sound from the exhaust. I'm not a car expert, but have hears similar popping sound from other high performance/race car.

Just wondering what makes this popping sound? Is it the exhaust, CAI, engine timing or all of the above?

Thx.

 

In the case of the JCW vs MCS, I heard it as the engine timing. I'm not sure the science behind burble in general, though.

 

From what I understand, they richen the mixture when the throttle is closed, and this causes the popping/burbling sound. It's fairly subtle in standard mode, but really barks between shifts and on deceleration in sport mode. I've found myself driving around with the windows and sunroof open just to hear it. I LOVE this aspect of the car.

 

Isn't it the popping they somehow removed from the standard US MCS through ECU tuning? My UK Stage 1 JCW pops all the time, it's a lovely sound

 

I think you are correct, all the R53's (MCS and JCW MCS) had this little pop/burble on the over run. Did the R50's do this too? If I'm not mistaken, I seem to remember the hearing MC's (non S) doing this as well.

I think the sound is made by injecting a little gas into the cylinders when the throttle is up (not giving it gas) and the engine is coasting.

I heard they took it out of the R56's (MCS non JCW) for emissions reasons via a change in the software but put it back into the JCW's on purpose as it gives the MINI that much more coolness/character.

 

Do you mean like the one in this video?

 

Yep, that's it! It sounds cool

Thanks for the explanation.

What MotorHead and DaveC said maskes sense as the video seems to indicate the popping when the throttle is let up. So all it take is an ECU reprogramming? I'm trying to understand the benefit of this in terms of performance other than the cool factor.

 

If I understand it right, there is no performance benefit.

Am I right to say that the burble/popping is from the engine firing occasionally after the throttle is let up?

 

I don't even need to roll down the window!! I am surprised the police don't pull me over. I keep on thinking, how will I explain to them that it came from the factory that way!!!

 

The popping is purely a software matter.. when you lift-off the accelerator a little bit of fuel is still injected and because of the heat of the headers the unburnt fuel 'explodes'.

All Cooper S models have this, only the US-spec models lack this feature... also compared to EU-spec cars the exhaust is more silenced.

This is a fully stock Clubman S exhaust, EU-spec:
http://s269.photobucket.com/albums/j...=VIDEO_006.flv

You can definitely hear the popping... most of the time it's pretty subtle and inside the car you can't really hear it that clear, except for the big pops from time to time. Sport-mode 'on' makes it pop more I believe.

With the JCW factory car I believe there are no more differences between EU and US-spec cars.. but I'm not sure.

 

Yep, no need for the stereo in this car! I took it through the hills on a rainy day and had to keep the windows cracked for the sound. Just fantastic.

 

So, the burble isn't dead? You just have to get a JCW (at least in the U.S.)?

 

I had an 02 MCS, then went to my current 06 JCW the popping is more prominent. My dealer told me it was software I also have the JCW header so it's even more so. Lean or rich mixture has nothing to do with it as my car was running very lean before my RMW Jan tune, there was no change in the popping after. I love it but my wife isn't a big fan. The sound does turn heads, I've passed pedestrians made the pop and then they turn Rally-ish!

 

Burble

I had one guy from work on a lunch run who thought there was something wrong with the car

 

If i get the JCW Stage 1 Kit for my MCS, will it also make this noise? I know that they reflash the ECU with a different mapping... would that be the European mapping?

 

no, the US stage 1 (dealer installed) kit remap just raises the boost slightly, the slight increase in sound is due to a muffler change, but there's no burble or pop like the factory JCW cars.

I'm still waiting for one of the aftermarket reflashes to come out with the burble & pop re-enabled.

 

There was a technical service bulletin sent to the MINI dealers a while back regarding the burble (I guess they had customers asking about it). The bulletin was pretty funny.

I'm paraphrasing, but it basically said "The noise you're hearing is normal. It's supposed to be there, and there's nothing we can do to you car to remove it. And if you *don't* have the burble and would like to have it, we can't help you with that, either."

 

I like the pop !
You guys need to hear the pop on my cousins 650 WoW (he has a strait pipe)

 

I had a 650 Ninja that I tinkered with the exhaust...

that thing crackled and popped and it was LOUD. Loud until it replaced the front fender on a red Ford Explorer that ran a stop sign and and found me. Good times though!