I have a 2006 MCS GP and I get a whoosh sound (like a wind rushing sound) coming from the exhaust during wide open throttle (WOT) accelerations. The whoosh sounds starts at about 5,000 RPM. It occurs with the stock JCW, resonator eliminated JCW, and Milltek exhausts. The whoosh only slightly occurs with the Borla Sport exhaust. It is annoying to me because the loud whoosh tends to drown out the nice exhaust tone.

I am wondering if this whoosh is unique the the GP with the missing sound insulation. I never heard the whoosh in my 2003 MCS with the stock or Borla Sport exhaust. Is the loud whoosh sound heard in JCW MCS or MCS cars with JCW or Milltek exhausts installed?

 

Is it the Flap on your air boxs opening?

 

No it is not the air box flap opening. I have the flap removed. Also, the sound is definitely coming from the rear of the car and the exhaust. It sounds like the Ford with the 429 CID engine, that we had when I was a kid, when my Dad would floor it "blow out the exhaust".

 

Both my Cooper S's (2002 with JCW exhuast, and 2005 with Custom Exhuast) make that wooshing sound. It is much more noticable with a pullied car. Nothing to worry about

 

I've got a playmini exhaust on my 2005 Cooper S and I can here that wooshing sound when I put my rear seats down and drive hard.

 

quickmni
I also have a GP and have the same sounds. I agree with your thoughts.
Steve

 

Thanks for the replies. It appears that the whoosh sound is normal but probably accentuated in the GP because of no back seat or rear sound insulation. The whoosh sure ruins a good sounding exhaust tone. I might try to figure out where the sound is mainly entering the GP so that I can apply insulation to that area. However, I suspect most of the sound is coming in the rear air vents so there is not much that can be done.

I can not seem to find the perfect exhaust for the GP. The stock JCW is too quiet, the resonator eliminated JCW is too snap/crackle/pop, the Borla Sport drones too much while cruising, and the Milltek removes the drone, is almost loud enough but has the WOT whoosh. I guess I live with the whoosh but that takes some of the fun of WOT noises.

 

Can anyone point me in the direction of a "How to" with pictures to take off the top of the JCW CAI? I want to change the filter to an aftermarket one.

 

Excellent instrutions are available from Mini Madness. It is available on the mini-madness.com LINKS tab and then the Instruction Manual section.
Here is a link to their pdf file (but not sure the link will work):

http://www.mini-madness.com/pdf_file...structions.pdf

 

Awesome. Thanks!

 

quikmni - My GP makes the same noise and I'm with you it would be great to get the exhaust sounds more authoritative! The alternatives you described are some of the "top picks" by many. What other options do we have?

 

Mine does the same......on a slightly different "note", I change the stock filter to a K&N filter and removed the plug.....HOLY CRAP!! The car pulls stronger and more evenly across the RPM range, expecially once the flap opens!!

 

I have it too with my Milltek!

Can only really hear it when I drive with the rear seats down. I kinda thought it was the fuel pump?

 

I think others have reported the same issue with Milltek's on the dyno. I have their cat-back on my car and never noticed a whoosh while driving hard, but the car has not been on a dyno...

 

whooshing = restriction

 

I agree in general with the comment that whooshing = restriction but I had the same Borla Sport exhaust on my 2003 MCS (15% pulley, CAI, ECU Programming) and on my 2006 GP. I heard no whoosh on the 2003 MCS but could hear whoosh in the 2006 GP. The whoosh is louder the with the JCW or Milltek than the Borla.

 

I've been trying for a week to duplicate your whoosh with no luck. I have a stock 06 JCW and all I hear are the roar from the exhaust and the whine from the supercharger.
I do like the "burble" on overrrun between 3-2,000 RPM.
And it is much louder when you lower the rear seats.

 

I have an 06 JCW with a Milteck cat back and haven't heard this sound.

Whooshless in Alabama.

 

I think the whoosh might be unique to the GP. Based on some experimenting I did this weekend I think the whoosh might have more to do with the rear vents in the GP than the exhaust. If I have the windows up with just front vents (non-recirculate mode), I get a loud whoosh during WOT in the 5000-7000 RPM range. If I switch the HVAC to recirculate mode the whoosh is less. If I open a window the whoosh is gone. I whoosh noise appears to be coming in from the two rear vents below the boot.

I assume the rear vents are the same design as other Minis. The only relevant differences that I know about on the GP is the under body pan tray which make the bottom of the car very smooth and less insulation in the rear panels. I suspect it is a combination of the smooth bottom and less insulation that makes the difference.

 

My non-GP wooshes. It's not unique. I agree about the vents.

mb

 

I've got a JCW, and I never noticed the whoosh with the JCW exhaust. I now have a Milltek, and I still don't have any whoosh.

The only whoosh I hear is from my unflapped intake.