MINI One and Cooper mufflers/silencers/endcans/back boxes... Are choking the performa

[Jeffy]

I read a piece that said that the design is terrible- so I took it off from behind the resonator and cut the top off of the muffler, from the front end to about 8" back. You wouldn't believe your eyes. First, the inlet pipe goes in through an open chamber, into a fiberglass-packed section where it does a sharp U-turn back into the open chamber, which sucks, but that's not the worst of it! The outlet pipe (with the chromed tip) starts in the open chamber, but has a downward turn with only 1/4" between its inlet and the floor of the muffler!! I decided to modify the original muffler and maintain the original appearance. Needless to say, I made it easier for exhaust to flow out of this thing! My results are as follows: More power, similar sound (except at wide open throttle), less effort squirting around town at part-throttle. If I didn't tell you I modified it, you'd never know. I can explain how I achieved this totally successful modification if there is enough interest shown (otherwise I'll just be faster by myself). Don't be slow, your holding up traffic! -love, Jeffy.

[lmassauk]

I would like to know!! Being the owner of a company car, means I can't really mod it that much. So if you can't tell its been modded all the better!!!

[Martyn21]

Yeah sounds good to me, Cheaper than a £200+ Stainless

[Jeffy]

Okay, for the 2 guys interested in a cheap mod that brings worth-while gains... Remove the pipe at the flange with the 2 15mm. nuts, then remove the 6 10mm. bolts holding the plate for the flexible mounting aft of that, then one of the 10mm. bolts holding the strap around the muffler. It's easy this way, do it. Do it. The corners around the top of the muffler are rounded, so cut in the center of the corner with a thin cut-off wheel and a die grinder. This way you can smack the edges back closed while welding the top back on. Cut about 8" back from the forward edge of the muffler, revealing an open chamber. Aft of that is one filled with fiberglass. Cut the piece of tubing out that goes all the way through this open chamber. Throw the piece of tubing over your right shoulder. Now, cut out the piece that angles towards the floor of the muffler. That piece is the one that finally exits the maze (I mean, muffler). Now measure the depth of the muffler and the distance between the inlet tube (now opened) and inside edge of the cut-off outlet tube, because now you will make a sheetmetal plate of the dimensions just described, and weld it into the open chamber, in a manner that will angle from the inlet towards the outlet, blocking the 2 holes that were a tight U-tube that exhaust formerly had to pass through. In spite of this, the muffler will not be loud- there's plenty of fiberglass aft of the open chamber, kind of like a padded cell- yell and scream all you want, nobody outside the room can hear you. Take a week-end to do this job, it's worth it! Looks same as before, but faster and more economical. Beat that! -Jeffy.

[Paul]

There's probably GOING to be more than two people interested, so thanks for sharing.

[camini]

Yes, sure am interested as well..
No pictures taken during the mod?
Would I be able to direct a technician to perform this job as I do not have the tools myself?

Great idea anyway!

[mini_macky]

what if i just have a custom free-flow pipe from the headers to the muffler done? will that have the same effect as your mod? any downsides to having the free-flow piping done?

[Jeffy]

As for having a mechanic perform these mods, jut show him my description of how to do it, and he will figure it out- the faults are quite obvious, once the top is cut off. As for the free flowing pipe leading to the muffler, They have found that the closer to the cylinder head the change is, the more effective it is (that is over simplified, but), so, your idea may yield gains- just remember that in spite of your big pipe, the exhaust must still be forced past that 1/4" gap at the bottom of the muffler to escape. As for fuel economy, I'm getting 35mpg, which is the same as before the muffler mod, but I am also driving with my foot into it more, since I get more result, but the truth is that I have been making mods since I bought it 2 months ago- it's my hobby and I never stop or am satisfied. -Jeffy.

[MarkW19]

Is there any change in sound to the car after this is done?

Has anyone else done it and found it worthwhile?