As the 3.2 conversion progressed I found a rare link from Up Fixin der Porsche describing the conversion of a stock muffler to sport. So, I had the muffler that came with the 3.2 and scrapped the silly headers of the era in favor of some nice headers from MSDS. Opening up the clam shell I welded two stubs into the pipe that originally was fed by a single inlet. Seems like it oughta work

Question to you all is whether any one else has done this? It will be the same single outlet but now dual inlet.

And I know

But don't have em here.

The mod you describe was published many years ago and performed on many hundreds of early 911 factory 2 in/1out mufflers. See below.

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You can add twin pipes to the factory muffler with or w/o the internal mods. However, The internals of aftermarket and/or later 1in/1out mufflers may not be the same. Of course, there's no way one can predict how it will sound after mods. except louder. Droning is to be avoided. YouTube provides several examples, but you may have to extrapolate mods vs. resultant sound. Engine mods and HEs/exhaust header type are also variables.

Here's one of many threads on the subject. A google search will reveal many more:
http://forums.pelicanparts.com/porsche-911...ry-muffler.html

As for the effectiveness of the mods, YMMV. Most are done to increase the exhaust level, but some mods can have a negative effect on MFI engines which seem to work better with a stock factory muffler.

Sherwood

Yeah, that was my inspiration. However, in my case I am hooking up the original muffler to the original pipe, except at dual locations from the headers rather than the single inlet from the twin heat exchangers that were limiting. Not looking for much but saving money with the mod, but the headers should provide more power. Just wondered if this was done with any of the six conversions in the teener world. Also, if it is plain old dumb, now is the time, although half the mod is finished. I would then have time to, shudder, buy a muffler. CSOB here.

I have one of these mufflers in my garage modified like above. It's pretty loud, which is why it's not on the car anymore.


I could see it beneficial for a 3.2, but on my 2.2S it only gave a little more punch at high RPM.

OK I am with my other computer. The first shot is what the 3.2 muffler looks like inside.
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The heat exchangers were built identical on both sides to save money. Exhaust was routed through a single pipe to a spot adjacent to the tail pipe. From there it goes through a pipe with different hole sizes and baffling.

I cut holes and ran stubs into that pipe. Thought I took more pictures.

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Here is the other half of the clam shell placed on for style. I will start by tacking and then go from there.

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I ended up making an alu support spreader. I got one of those tools that make indents and steps in sheet metal for X-mas and tried it on 1/8 th aluminum. So, whadayathink? Disaster in the making. Definitely Dansk as a better option?

The way I did mine I doubt it is louder or more potent. Looks sporty on your car though. I am not currently planning the dual sport tips. yet.

One thing to keep in mind as you make the mods is that the 3.2 muffler is different internally than the early mufflers since the 3.2 one is 1-in instead of 2. This is important if your headers are going to be 2-in (I assume they are). The reason the difference between 1-in and 2-in is important is the internal flow inside the muffler is different. Make sure you consider this as you modify the muffler so you have equal flow for both muffler inlets, or the muffler could potentially choke one of the inlets (and half of your engine).

Scott

Thanks Scott,
If you look at it I am connecting the two sides to the same pipe. However, the perforations on one side are different than on the other, although I would guess similar in area. Do you think I should try to open the pipe up a little to reduce any possible differences. The stubs in the photo are connected to holes cut in the inlet pipe sides. Of course I plan to cap the inlet, but wasn't looking for opening the muffler up like the sport version.