oem muffler hack

Originally Posted by szentej

The exhaust gasses from the right and left sides do not interact with each other. They each have a separate path through the muffler.
.

No. They do interact in the middle of the muffler. That first pic is misleading. The left and right inlets connect in the middle; it is straight though from end to end. perforations along that length determine where the gas spills out into which chamber.


In the 986 S, there are gaps along the main length also, not sure about the base 986.

[Peer]

Many thanks to szentej for explaining the muffler flow -- so yes, I now finally get it.

szentej wrote:
> You probably will not gain any performance on making
> mods to the muffler. Only increased sound.

I'm not sure if you have seen this a dyno chart for a hacked muffler. I'm just curious what they exactly did to it, since it's quite an improvement, especially the torque.

-- peer

[Kirk]

Originally Posted by boxsterz

No. They do interact in the middle of the muffler. That first pic is misleading. The left and right inlets connect in the middle; it is straight though from end to end. perforations along that length determine where the gas spills out into which chamber.

Correct... the pipe in the very middle equalizes the pressure between the two sides that come into the muffler. Many motorcycle exhausts (like Harely Sportsters) have these equalizing pipes that connect the two exhaust outlets together.

One more correction... there are only two chambers on each side. After gases flow into the second chamber they are routed through piping out the exhaust tips. It's hard to see in the photos. I changed the brightness of the Tool Pants photo before I posted it to try to make it easier to see, but the pipe from the second chamber looks like it goes straight to the exhaust tip and not into that central chamber. I believe the central chamber does not receive any exhaust gases, but only houses the various piping. At least that's the way it is on the S muffler, you can't really see it in the picture of the standard Boxster muffler.

Kirk

[Tool Pants]

Here is a second picture of the first (base Boxster) muffler with the packing removed.

The inside of the base muffler looks the same as the S muffler in the second picture. The only difference I can see is the spacing of the 2 tubes that exit the can to the tip(s).

[szentej]

"I'm not sure if you have seen this a dyno chart for a hacked muffler. I'm just curious what they exactly did to it, since it's quite an improvement, especially the torque.

-- peer "

The dyno chart shows the difference between a stock oem muffler and a "Sporttech" muffler. I don't think the sporttech is a hacked oem muffler.

"No. They do interact in the middle of the muffler. That first pic is misleading. The left and right inlets connect in the middle; it is straight though from end to end. perforations along that length determine where the gas spills out into which chamber.

boxsterz"

The inlet pipes on my 1998 muffler do not go through from end to end. When inserting a dowel into one side or the other there is an obstruction about 18 inches into the muffler.
You may be correct about the perforations determining which chambers the gasses flow into. There is a difference between the two pictures that were posted. I don't if the first one is from an older muffler.
From the picture Toolpants posted it appears that the perforations would cause the majority of the gasses to flow as I indicated in my ealier post.

John

Originally Posted by szentej

The inlet pipes on my 1998 muffler do not go through from end to end. When inserting a dowel into one side or the other there is an obstruction about 18 inches into the muffler.

John

That's interesting. Guess it's fair to say the 2.5 mufflers are different.

[Peer]

szentej wrote:
> The dyno chart shows the difference between a stock oem muffler and
> a "Sporttech" muffler. I don't think the sporttech is a hacked oem muffler.

Actually, the so-called sporttech muffler is a hacked oem muffler.

-- peer

[szentej]

I stand corrected. The Sporttech muffler is a hacked muffler. You send them your muffler, they open it up, take out the guts, add bypass pipes (from the inlet to the tail pipe) and reseal. And you get to pay them $500 for parts and labor.
The above option is cheaper than installing a Porsch Sport Exhaust (big $$$$). The Porsche Sport Exhaust utilizes a bypass system that is controlled by a switch and/or speed sensor. But even Porsche does not claim any significant power gains with this mod.
Or you can go to PPBB dot COM and search for "Pedro Sport Exhaust" to see how to have bypass pipes installed on you muffler at a much reduced price.

John

[Peer]

Originally Posted by szentej

I stand corrected. The Sporttech muffler is a hacked muffler. You send them your muffler, they open it up, take out the guts, add bypass pipes (from the inlet to the tail pipe) and reseal. And you get to pay them $500 for parts and labor.
The above option is cheaper than installing a Porsch Sport Exhaust (big $$$$). The Porsche Sport Exhaust utilizes a bypass system that is controlled by a switch and/or speed sensor. But even Porsche does not claim any significant power gains with this mod.
Or you can go to PPBB dot COM and search for "Pedro Sport Exhaust" to see how to have bypass pipes installed on you muffler at a much reduced price.

John

The difference is that the Pedro Exhaust (and the Porsche Sport Exhaust) don't claim any power gains -- while the Stpotech hack does. Hence, I'm curious what the Sportech guys do to the muffler that supposedly will increase its power (especially the torque).

-- peer