I know that I will probably be yelled at but I got to ask, can you put the stock muffler back on after a JCW Stage 1 tuning kit or would that cause problems with the ECU tune expecting it?

I always wanted a JCW upgrade and liked the way they sounded outside but no idea it would be so LOUD on the interstate that I can hardly think. It gives me a headache after about an hour of it roaring. Plus the vibrations when taking off is making everything rattle that didn't before.

Saw that the stock JCW muffler is larger and may quiten it a little but I hate to pay more for it and it still really be as loud. So is this possible or am I just screwed? Heard of Dynamat but never used it. Can't imagine it doing good enough for me but maybe if I had to.

Bob

 

It's a good question. On the Clubman the JCW tuning kit. the mufflers have the same part numbers as the S, they just remove the center resonator and install a straight section of pipe. I couldn't see why you couldn't leave the resonator in place and keep the factory mufflers?

 

Hmmm...I've been thinking about having this put on because I think that as much as anything the stock sound on my 2010 MCS is far too quiet (although a little extra whp would be nice as well)...I actually like the sound of my wife's stock 2006 MCS.

Is it really that loud?...that's kind of concerning to hear...

 

Its not too loud at all. The only time it is noticably louder is when you are accelerating. At speed there is no difference between the stock and jcw set-up. And most important, no drone.
The mufflers on the clubman jcw kit are shorter than the stock s mufflers, likely the same ones on the factory jcws. Also one of the two cats on the stock s exhaust is removed and a straight pipe is inserted. I have the parts that were removed from my car and they are not the same as the ones that went back in.
I do not know if going back to stock raises any cel issues, but you will likely lose the fancy engraved tips that come on the kit

 

"The mufflers on the clubman jcw kit are shorter than the stock s mufflers, likely the same ones on the factory jcws".

Both my old and "new" JCW mufflers measure 13 3/4" long and have the same part numbers as my old ones, 325989.

 

turbotraveller - you are right about at speed there is little difference, to a point. At about 70, the sound comes back and by 75-80 it is nearly as loud as when it is accellerating. Do you have a stick?? Maybe the auto trans causes the rpms to be higher at that speed then you have.

all i know is I travel on the interstate twice a week for about an hour and a half and now when I get done, and come off the exit to normal speeds and the sound is gone, the back of by head is booming. I don't know what a drone is but that word sounds kind of like the sound i hear in my head.

it sucks but i don't like to drive my mini any more the booming vibrations just make my head hurt after a while. I don't mind loudness to a point but this seems ridiculous. i don't know if i should try the larger jcw factory muffler like some say or go back and hope it don't mess up the jcw tuning part.

 

consider getting the front muffler off the factory JCW, the resonator is larger and will probably help. see if anyone in your area has one installed and ask for a ride along.

 

I have a stage 1 kit on my convertible. I do not think it is loud at all. I think its just right. Drive a 5.0 mustang with an H-pipe without cats and flowmasters. Now that is loud and has a drone! The mini is nothing.

 

I used insulation and sound deadening instead. It can work but it does take some time.

 

I stand corrected, Big Jim, you are right. Both the new and old mufflers have the same numbers stamped into them.
The new jcws also have a second set of numbers engraved in them, likely because they come with a different tip. They have to have some way to tell them apart.
I have found that much of the exhaust noise is related to load. The harder the engine works, the louder it is. I think it is louder with two people in the car, and while I do not think it is to loud on the freeway, the engine is working harder. Don't confuse this with engine rpm, it is more a function of how hard the engine is working for a given speed and gear.
I have an automatic and one of the loudest times is if I am running low rpms at low speed in too high of a gear, which is easy to do when you are just trundling through the neighborhood. Unless you downshift, it lets out a real farty sound before it starts to wind up and quiet down. All the more reason to not slow down for those 25 mph corners

 

The JCW Stage 1 muffler seems to be most boomy at 2800 to 3500 rpms, under medium to high load.