I like the look of the M&K sport muffler, but it's a little too loud for me, and there is a drone at 2800-3000 rpm.

I have the old B&B 914-6 headers and there is a lot of room to add another small inline muffler on each side. Is this is a horrible idea? Would it be too quiet? I'd be going from 1 to 3 mufflers. I would be sort of like where the 993s/etc have their catalytic converters, but I'd be using small mufflers (less heat).

Has anyone tried this?

-Steve

id like to see this!! maybe dyno it before and after as well to see what/if any power loss? good luck Dave

I don't know if it will work, but 2 of those + welding, etc, so $550 to find out. I had the same dilemma - first I had a custom 2/2 made and specifically requested that it be quiet. It turned out too loud for a street car, plus drone. It will be in the classifieds soon. I then bought a dansk sport 2/1 and had a shop cut out a chunk to fit my 915/wevo. 475 for dansk plus 400, installed (incl bracket). Problem solved. Louder than stock, but reasonable, less loud than M&K 2/1 I'm told, and no drone.

I'm a quiet car kinda guy. Go for it!

The ones that PMS used to sell as their "Laguna" mufflers are very quiet until you get into the 5k rpm range ...

Andy

The M&K 2 in 2 out are notorious for drone. I have the 2 in 1 out and no drone and it's "relatively" quiet.

I would be more inclined to go to a 2-in / 1-out M&K or a factory type muffler such as a Dansk.

Why not " cap " the passenger side tailpipe of the muffler ? Voila instant 2 in 1 out. I have a Gen II M&K 2 in 2 out on my SC with SSI's. Yes she is loud when both outlets are open but when I slide in the cap she tones right down. The cap I have is internal so it slips " in " the tailpipe vs. " over " the pipe. So it is nearly invisible when installed. Basically it is a piece of pipe that fits inside the tailpipe but on one end it has a piece of metal welded to it to make it a cap. A nut is welded to the inside of the pipe cap. You drill one hole in the tailpipe, I drilled mine on the bottom. You slide the cap in, align the hole to the nut and install one SS bolt. Very clean and easy install. When you are at a AX or DE and want to make some noise you undo one bolt and slide it out. It can be tight due to carbon/exhaust buildup but I have found if I coat the cap with a thin layer of grease that makes it much easier to remove.
I have a pre Gen I 2 in 2 out with headers on the 914 GT clone and for some reason she is a little quieter but still has a slight drone. I haven't gotten around to making a internal cap but I will eventually. Another possibility is to experiment with muffler inserts. Similiar to what motorcycles use there are lots of different designs.

Another method for a quiet system without too much work....They are also tucked up well and hidden

Click to view attachment
Click to view attachment

Funny thing is I was almost going to sell my bus because of the droning engine, spent $300 in dynamat, even wearing ear plugs...Brand new dual "Quiet pac". I was sitting at the back up the bus wondering WTF to do and I stuck my hand over one of the exhaust tips....and wow. The noise dropped in half. I lopped the tip and tack welded a patch over the stub.
Instant difference.

Patch is starting to come off so I need to weld it shut proper.

I have a cap for my M&K "R" style muffler. It does tone it down a bit but the "R" has minimal baffling anyway. Most of the sound on my car is from the induction and other engine noise -- the exhaust is just one factor. From inside the car I can barely tell if the pipe is capped or open.

Need pics and video