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Discussion Starter #1
About three weeks ago, my midpipe cracked mostly open before the main cat in the flex pipe while driving up a friends driveway. It had been slightly cracked before but I didn't get it fixed because it wasn't a major problem. The sound was phenomenal, with my only complaints while driving it for two weeks waiting for my high flow cat/midpipe from NPG to arrive being that it was too loud (although I went to church with my mom in it and she didn't mind too much), it vibrated the cabin too much since it was right under the center tunnel, and it had a horrible and sometimes embarrassing rasp because it was before the resonator.

After fixing it a few days ago, it was simply too quiet (Camry quiet), and I missed the sound. I didn't want it to be too loud, just to have an enjoyable tone, and to be able to hear the pops and snaps and burbles clearly like I did with the pipe cracked. So I asked my friend with an angle grinder to cut open two sections on the bottom of the factory mufflers. The whole job took about 30 minutes including clean up and the metal is not thick. Basically, we started by cutting the bottom section just before where the tips would exit ("front" of muffler), then tested how loud it was. We decided to also cut the rear section right where the drainage hole is in the mufflers after that.

Doing this, we saw the open ends of a separate pipe (the baffle pipe), which means that there are at least three chambers in our muffler. The pipe enters from the Y pipe, goes in to the middle of the muffler, flows either through perforations or more unknown baffles to the other pipe sitting in there, which enters to separate chambers in the front and rear of the muffler, and returns back through the main chamber and out the main outlet in stock configuration.

With the two end baffle chambers open, it has a sound comparable to the Tanabe Medallion axle back I would say. Around town, it's very quiet, and at certain rpms it reaches a frequency where it's almost silent (some sound waves completely canceling each other out then), and at other throttle positions, it's very loud, boomy, and resonant. It has a lovely melodic rumble, and is quiet in the cabin around town. You can also hear deep booming pops when coasting and decelerating at low rpms. Unfortunately, it's horrible horrible drone on the highway. I think most of this is from the rear baffle section being open since it's closer to under the rear seats, and accelerating on the highway at or near 3k rpm with the throttle open makes the whole cabin almost but not quite unbearable.

My plan is to weld the rear baffle pipe shut and weld the floor of the muffler back shut and see how that helps. Hopefully it brings back some of the rawness and pops, and will force flow back through the main chamber and other chamber, preventing drone.

I'll report what happens if it gets done. Hopefully I can get some photos and a video on here too.
 

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Discussion Starter #2
Here's how it sounded while the midpipe was half open;
 

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Sounds like you may as well just grab a HOLE saw and punch holes in the muff right through that center chamber! Obviously it must fit through the tail pipe hole or unbolt and go from the other side! lol

Have Fun!
 

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Discussion Starter #6
Thank you everyone! I'll try to get a photo of the cuts in the mufflers. After living with the sound for a few months, it still hasn't gotten old. I enjoy it. The only thing I don't like is that it sounds a bit ricey to me between 1500-2500rpm. But I asked a friend to drive it up the block and go for it. When you get past 2500, it flat out screams. Not like it did in the video with the midpipe, but it still has a great sound.

Also, the last time a group of my friends went out for dinner I asked one of my friends to drive while I sat in the backseat. Surprisingly for the one of the open baffles being in the rear of the muffler closer to rear seats, it wasn't really loud or uncomfortable at all. Also, when it pops and snaps, you will feel it. Kind of like in a WRX.

The comfort level may be due to the sound deadening I've done. I have double layers on the trunk floor where the muffler would be under it, as well as under the rear seats and most of the floor in the entire car. As well as the rear deck, all doors, and other parts to avoid vibration. The car feels really solid.
 

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Discussion Starter #7
Also, I'll get an in car video so you guys know how it sounds now.
 

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Discussion Starter #10
Thank you. It was driving me nuts in the last scene at night with the camera because that's not a particularly good area.
That is a very good video man. Lol what if someone just took your vidcam while you were driving away?:D

Sent from AutoGuide.com Free App
 

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Discussion Starter #11
Just an update for everyone who asked; I'm working on editing the video of the current setup so you can hear what I described in the first post. It will have outside the car, and in car clips in a number of everyday situations.
 

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Discussion Starter #12
Out of sheer curiosity, I wonder if anyone has ever or could measure the dB of a straight piped V6. It would be nice to know how loud it gets and if it will actually break any limits.

PS. I know I promised a video. Now that the semester is almost over (two more finals for me) and my semester job is over, I have time to edit.
 

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Sounds very similar to what my stock exhaust sounded like 6 months after my headers and catless y pipe had their way with it. I personally hated the sound above 3000 rpm or when walking on it in any gear so I bought an Injen Exhaust that gives me all the pops when decelerating and a nicer mellower (but still loud) sound. It's not my thing but glad to see you're having fun!
 

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Discussion Starter #14
Thanks Canadian6. I'm going to get started editing the video so you guys can finally hear what it sounds like now.
 

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Discussion Starter #15
 

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Discussion Starter #17
Thank you. This is with the floor under both the front and rear baffles on the mufflers cut open.

Sounds good is this with the metal piece welded back on or is it still off? Kinda sounds like when I tried the washer mod on the muffler flanges.
 

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I actually really like the sound in the new video! Not near as raspy as the previous one. I'd be interested to see if the sound changes over time as the packing possibly gets blown out cause I know mine sure did haha
 
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