Third Cat or Resonator

[DJE624]

In this picture, what is the muffler type item just to the left of the number 12.  Is it a Third Cat or a resonator?  I seen it referred to as both.  What purpose does it serve?  I know some guys install an X pipe there.  Could you just put two straight pipes there?  Would there be any benefit either way?  I guess the X would kind of even out the exhaust. 

[bpd1151]

So confused as there are three number 12's in that diagram

I think that number (12) is taunting you Dave. Lol.

That item I believe you are referring to, is a third cat.

My understanding is, that by inserting a 'X' pipe in that location, that that design helps scavenge the exhaust in a more benficial, even matter.

Rather than just putting two straight pipes in that same location.

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[SRT82ECOBOOST]

Number 12 is an exhaust hangar and you do not want an x-pipe as it only creates more restriction.

[DJE624]

So confused as there are three number 12's in that diagram
I think that number (12) is taunting you Dave. Lol.

LOL I didn't even see those other hangers.  I was so focused! LOL  There are actually 5! 

[EcoBrick Bob]

The first item that you notice after the flanges that hook up to the downpipes with cats, is the 3rd cat.  It has 2 inlets and 2 outlets and is very short.  about a foot later is the resonator that also has 2 inlets and outlets.  The NESHO Mid-pipe replaces both the 3rd cat and mid-pipe resonator.  In my instance, I added a second set of flanges behind the resonator.  This allows me to switch the NESHO mid-pipe with the stock section, to which I also welded in flanges.  Frankly, when sitting in the front 2 rows of Flex,  the NESHO pipe is slightly louder, but not at all annoying.. But... if you are in the far back seating... IT's LOUD!!! ... mostly because of the resonance & RPM range.

[DJE624]

Ok guys, Thanks! 

[EcoPowerParts]

Next time right click on the image and choose edit. Then use paint to draw a little circle around what you're talking about and save the image.

[SHODYOU]

From my understanding the x-pipe helps spool buy scavenging, working as it would on an NA car. But once turbos are kicking its not needed as exhaust is no longer pulsing, its a steady stream. At this point you want as little restriction as possible.
It's a compromise, like most everything else.
Plus an x-pipe quiets the car down some and helps tone.

I cut out the 3rd cat and midmuffler... but replaced it with a Magnaflow TruX muffler. Was affraid it'd get raspy with a bare x so I got the muffler version.
Magnaflow part #11386

[thatsmrgimp2u]

From my understanding the x-pipe helps spool buy scavenging, working as it would on an NA car. But once turbos are kicking its not needed as exhaust is no longer pulsing, its a steady stream. At this point you want as little restriction as possible.
It's a compromise, like most everything else.
Plus an x-pipe quiets the car down some and helps tone.

I cut out the 3rd cat and midmuffler... but replaced it with a Magnaflow TruX muffler. Was affraid it'd get raspy with a bare x so I got the muffler version.
Magnaflow part #11386

How does that sound? Still using the stock rear mufflers?

I'm wanting to get a bit more sound and reduce back pressure. I've heard plain xpipes in place of the cat/resonators and can't say I'm fond of it...

2011 ISM SHO; Airaid Intake

[EcoBrick Bob]

In non-turbo vehicles an X-pipe is supposed to help high end power.  An H-pipe helps low end.  I have one of each on my 2 G8's.  The H-pipe one was louder  initially, but at cruising is quieter... Guessing it is the pitch of the tone or something.  It also seemed to launch slightly better before I added the stall converter in the more heavily modded one.

Kirk at NESHO was the one who suggested the x-pipe and who used it in the few full exhaust systems he built and sold for the SHO.

[SHODYOU]

From my understanding the x-pipe helps spool buy scavenging, working as it would on an NA car. But once turbos are kicking its not needed as exhaust is no longer pulsing, its a steady stream. At this point you want as little restriction as possible.
It's a compromise, like most everything else.
Plus an x-pipe quiets the car down some and helps tone.

I cut out the 3rd cat and midmuffler... but replaced it with a Magnaflow TruX muffler. Was affraid it'd get raspy with a bare x so I got the muffler version.
Magnaflow part #11386

How does that sound? Still using the stock rear mufflers?

I'm wanting to get a bit more sound and reduce back pressure. I've heard plain xpipes in place of the cat/resonators and can't say I'm fond of it...

2011 ISM SHO; Airaid Intake

Its on a dynomax axleback too... louder than factory but zero rasp and very little interior sound, no drone.
Even after I installed the o/r downpipes its still quiet, just a hint of turbo whistle under light load.
I'm happy, louder than stock but no raspy/ricer sound... smooth tone.

[n8rfastback]

I'm running an x pipe in place of the third cat, then two glasspacks in place of the resonater, then straight pipes out to the bumper with tips on them...  I only get drone around 1800 rpm, otherwise it sounds  great!

[DJE624]

On what?

[SHODYOU]

I think I saw a system that fits that description on shoforums... was pypes parts iirc.
If its the same one its an SHO

[Courier6]

On what?

I am starting to see the value of your signature suggestion.