Exhaust options

[Keone_T78]

What's up? Guys with 4.2L I6 what kind of exhaust are you running ??? I started off with a 3 chamber Flowmaster ,single muffler & 1 tailpipe . Got it replaced cause the pitch was too high. My friends crowned me cause it sounded like an import. Currently I'm running 2 magna flow mufflers. Sounds a whole lot better but vibration in the cabin is LOUD. Gotta save up to redo my exhaust again. I'm thinking about running 1 magna flow w/ dual out. Thoughts ???

 

[gmcman]

Stock.

I actually enjoy the quiet ride with MPG and the stock setup is well thought out.

 

[Keone_T78]

I do like the sound of some exhaust . Wish I had a V8 instead :/ oh well !

 

[dmanns67]

I think most of us just cut the resonator off and call it a day. Most that do a muffler swap complain that it sounds ricey or have a horrible cabin drone at highway speeds.

 

[Keone_T78]

Sure does ! Once I'm above 1500 rpm's it's not bad @ all. Huge mistake on installing 2 mufflers. Space was tight so both mufflers ended up under the back bumper. Damn I wish I knew a welder in Vegas !!

 

[Envoy_04]

I'm running stock muffler with a homemade ultra high flow cat and a resonator delete. Idle sounds AWESOME, like a V8 really. Drone isn't actually bad at all that way either and the ricey sound isn't there at any RPM, just a slightly louder and more mean sounding exhaust note. I like it so well that if the stock muffler ever rusts out I won't even think of going with an aftermarket performance type replacement, I'll go back with stock.

 

[Midnyteryder196]

I'm running stock muffler with a homemade ultra high flow cat and a resonator delete. Idle sounds AWESOME, like a V8 really. Drone isn't actually bad at all that way either and the ricey sound isn't there at any RPM, just a slightly louder and more mean sounding exhaust note. I like it so well that if the stock muffler ever rusts out I won't even think of going with an aftermarket performance type replacement, I'll go back with stock.

What you running for downstream o2 sensor? Heard if u mess with cat that it will throw the tune off..

 

[Keone_T78]

V8 sound is what I was trying to achieve . But after 2 exhaust mods, I want all & any info I can before 1 last mod.

 

[DFWWIZ]

I do like the sound of some exhaust . Wish I had a V8 instead :/ oh well !

Nothing like the sound of a V8...........especially a tuned LS2...........with forged bottom end...........ported/polished heads...........Comp cam.........OBX headers........no cats.......ported/polished throttle body......Jettstream STG 3 CAI.....Flowmaster 40 series 3" in dual 2.5" out....and an open Badlanz cutout. :wootwoot:
(click on the pic and tell me if I'm wrong)

 

[Keone_T78]

Damn u !!! Lol man thats awesome. I've had my Envoy since 05, it's been good to me all these years. I really want a SS. I'm just having a hard time parting with it. I'm assuming you're pushing 400+ HP

 

[DFWWIZ]

Damn u !!! Lol man thats awesome. I've had my Envoy since 05, it's been good to me all these years. I really want a SS. I'm just having a hard time parting with it. I'm assuming you're pushing 400+ HP

Oh yea its up around 500. I'll find out in 2 weeks what it runs in the 1/4 at Beach Bend in Bowling Green at TBSS Nationals. I also have the Dorman E-fans, a Phoenix built trans with Corvette servos, Oregon Performance billet 4th servo, Transgo HD 2 shift kit and a 3200 stall. And a "get out of the way of the air flow" hide-a-plate.

 

[Keone_T78]

Oh yea its up around 500. I'll find out in 2 weeks what it runs in the 1/4 at Beach Bend in Bowling Green at TBSS Nationals. I also have the Dorman E-fans, a Phoenix built trans with Corvette servos, Oregon Performance billet 4th servo, Transgo HD 2 shift kit and a 3200 stall. And a "get out of the way of the air flow" hide-a-plate.

Haha that's sweet! I had a guy offer me $6000 for my envoy. I thought about it but declined his offer. I really want a Trailblazer SS. Or if I can install a LS1 or LS2 in my envoy would be sick . My neighbor who works on cars a lot said it would be a headache to do. I'll get a Trailblazer SS one day..

 

[Envoy_04]

What you running for downstream o2 sensor? Heard if u mess with cat that it will throw the tune off..

It does mess with the tune, so you've got two options. One is to build a cheap O2 sensor spacer out of spark plug non-foulers, one drilled out 1/2 " for the sensor to go in and one left as is. Then screw the normal one into the exhaust, the drilled one into that, and the sensor into the drilled one. That'll keep a CEL from popping up, but it still won't run as well as if you have the pcm tuned specifically for no cat. I did the spacer originally, but it was only a week or so before I ordered a custom tune from PCMofNC. I did it that way intentionally because I wanted all the mods that would effect a tune to be done before I got one.

 

[smt 59]

I run a Borla cat back system, sounds better than stock with very little cabin drone, nice sound when you get on the gas and I think it looks pretty cool As well.
View attachment 34291

 

[IllogicTC]

I think most of us just cut the resonator off and call it a day. Most that do a muffler swap complain that it sounds ricey or have a horrible cabin drone at highway speeds.

The thing with the drone is then you can't tell if your wheel bearings are taking a dump (yet again)

 

[dmanns67]

I run a Borla cat back system, sounds better than stock with very little cabin drone, nice sound when you get on the gas and I think it looks pretty cool As well.
View attachment 21958

Sound clip? Looks good

The thing with the drone is then you can't tell if your wheel bearings are taking a dump (yet again)

Already replaced wheel bearings. I should be good for another 70k miles

 

[smt 59]

Sound clip? Looks good



Already replaced wheel bearings. I should be good for another 70k miles

In the morning.

 

[Keone_T78]

I run a Borla cat back system, sounds better than stock with very little cabin drone, nice sound when you get on the gas and I think it looks pretty cool As well.
View attachment 21958

What did your Borla system run if u don't mind me asking ? Is your muffler sitting where the stock one was? You ride looks very similar to mine except I have the XL model .

 

[smt 59]

Everything fits exactly where the stock single system did with the addition of the drivers side pipe, the resonators are small and tuck in nicely, total cost with shipping and exchange was about $1100 and my friend installed it at his shop for a case of beer. I ordered through car ID, they are a middle man but had the best price. It has been raining here all day so I will get a sound clip tomorrow.

 

[Keone_T78]

Coo, I'm in the process of getting a welder to redo my exhaust. After this I'm done with working in my exhaust. I wanna upgrade to 22" wheels though, hopefully I can sell my 20's

 

[smt 59]

Good luck.

 

[Trios]

V8 sound is what I was trying to achieve . But after 2 exhaust mods, I want all & any info I can before 1 last mod.

View attachment 34319

 

[Keone_T78]

Haha ^^^ funny guy ! That's a good one

 

[Trios]

Haha ^^^ funny guy ! That's a good one

Actually, it's just the truth. Your I6 will never sound like a V8. You don't have the same number of cylinders. Inline sixes have 2 cylinders under a combustion stroke at any given part of the rotation; the V8 has overlapping combustion cycles. This means the I6 will run smoother than a V8 ever will, but they will have a totally different sound and no amount of exhaust modifications can change that.

 

[Keone_T78]

Yea that I know ! I've had my 03 Envoy since 05. Runs like a champ but what I have now is better then what I used have. Cabin drone is the biggest issue. I'm taking one more crack @ my exhaust then I'm done

 

[nagyiii]

Thinking of doing a resonator delete next weekend, am I correct in assuming you guys just straight pipe it out the back? What size pipe(s) will I need?

 

[djthumper]

SOme do it out the side and others of us have just left it off.

 

[dmanns67]

Thinking of doing a resonator delete next weekend, am I correct in assuming you guys just straight pipe it out the back? What size pipe(s) will I need?

2-1/2" OD by 18" long exhaust pipe with 2-1/2" exhaust clamp. A 9" long exhaust tip fits well if going out of the back.

All parts can be found at AutoZone or Advanved Auto.

 

[nagyiii]

Thanks dmanns67

 

[JamesL3]

Envoy_04 has a side exit setup using a Corsa p/n 14030 exhaust tip from a Tahoe/Yukon. A little welding and it came out great. Thought of doing something similar if not the same. Search "Corsa 14030" in the forum and you'll find the thread w/ pics.

 

[Mooseman]

I've got a JBA Headers single. Although it is for a shorty TB, made it fit my EXT using band clamps. The muffler was just loud and the drone was crazy even though there is a built in resonator in the tip. Switched the muffler to a Dynomax VT muffler. Lowered the noise a bit but still find it loud inside the truck. I found the power and MPG improved (sorry, no numbers, just butt-O-meter) but I can't take it anymore. Looking for something quieter in a 3" muffler.

But yeah, it doesn't sound like a V8. It sounds more like a fat ricer. Sounds cool but when cruising, it gets old.

 

[04tbottawa]

I've got a JBA Headers single. Although it is for a shorty TB, made it fit my EXT using band clamps. The muffler was just loud and the drone was crazy even though there is a built in resonator in the tip. Switched the muffler to a Dynomax VT muffler. Lowered the noise a bit but still find it loud inside the truck. I found the power and MPG improved (sorry, no numbers, just butt-O-meter) but I can't take it anymore. Looking for something quieter in a 3" muffler.

But yeah, it doesn't sound like a V8. It sounds more like a fat ricer. Sounds cool but when cruising, it gets old.

id like to take a look at your exhaust one day and if you decide to sell it depending on how it sounds id probably take it off your hands. I removed my resonator about an hour after I bought the tb and when the stock muffler rotted I bought a walker sound fx exhaust and this exhaust sounds great in idle and also when you romp on it. I just want something more pronounced.

 

[sirjr]

2-1/2" OD by 18" long exhaust pipe with 2-1/2" exhaust clamp. A 9" long exhaust tip fits well if going out of the back.

All parts can be found at AutoZone or Advanved Auto.

Thanks for posting this information. Would you have any pictures of this that you would be able to post? I would like to do this on my son's 2005 TB when he visits for Christmas.

 

[dmanns67]

Thanks for posting this information. Would you have any pictures of this that you would be able to post? I would like to do this on my son's 2005 TB when he visits for Christmas.

Relatively simple mod. I would recommend jacking up the vehicle and removing the rear passenger tire as it will give you more space to work. When cutting the resonator off, cut as close to the resonator as you can. That will leave enough OE exhaust pipe past the hanger to attach the exhaust clamp to. If you pick up your exhaust pipe from Advance Auto or Auto Zone, one end of the exhaust pipe is flared which is the end that the bolt on exhaust tip will go. The other end will insert inside of the OE exhaust pipe and the exhaust clamp will secure it in place.









I have since changed out the exhaust tip to the one below. The shape fits the cut out in the bumper much better. I had the exhaust tip welded to the exhaust pipe I got from Advance auto, but still used an exhaust clamp to secure the pipe in place. The tip was 9" long, but stuck out a little too far, so I had to take my Dremel and cut an inch or so off of the exhaust pipe.

 

[sirjr]

Great pictures. Thank you very much. This is a big help to me to visualize this project. Your modification looks great.

 

[sirjr]

Relatively simple mod. I would recommend jacking up the vehicle and removing the rear passenger tire as it will give you more space to work. When cutting the resonator off, cut as close to the resonator as you can. That will leave enough OE exhaust pipe past the hanger to attach the exhaust clamp to. If you pick up your exhaust pipe from Advance Auto or Auto Zone, one end of the exhaust pipe is flared which is the end that the bolt on exhaust tip will go. The other end will insert inside of the OE exhaust pipe and the exhaust clamp will secure it in place.

View attachment 73140

View attachment 73141

View attachment 73142

View attachment 73143

I have since changed out the exhaust tip to the one below. The shape fits the cut out in the bumper much better. I had the exhaust tip welded to the exhaust pipe I got from Advance auto, but still used an exhaust clamp to secure the pipe in place. The tip was 9" long, but stuck out a little too far, so I had to take my Dremel and cut an inch or so off of the exhaust pipe.

View attachment 73144

View attachment 73145

I have a few additional questions. Did you replace your rear bumper cover with one that has an exhaust cut out? Our bumper cover does not have a cut out and the tail pipe that exited the resonator just turned down. So I would just purchase an exhaust tip that turns down instead of straight out like the ones in your pictures.
We do not have any access to welding equipment. The 2 1/2" muffler clamp would be sufficient to connect the new tail pipe section to the OEM exhaust pipe where we cut it at the resonator?

 

[dmanns67]

I have a few additional questions. Did you replace your rear bumper cover with one that has an exhaust cut out? Our bumper cover does not have a cut out and the tail pipe that exited the resonator just turned down. So I would just purchase an exhaust tip that turns down instead of straight out like the ones in your pictures.
We do not have any access to welding equipment. The 2 1/2" muffler clamp would be sufficient to connect the new tail pipe section to the OEM exhaust pipe where we cut it at the resonator?

The bumper cover on my 07 TBLT is OE. If you dont want a straight pipe coming out of the rear, you can do a sweeping exhaust pipe that exits behind the rear tire, or just keep it simple clamp on a 90° turn down pipe. Exhaust clamp will be fine for whatever route you decide to proceed with.

 

[sirjr]

The bumper cover on my 07 TBLT is OE. If you dont want a straight pipe coming out of the rear, you can do a sweeping exhaust pipe that exits behind the rear tire, or just keep it simple clamp on a 90° turn down pipe. Exhaust clamp will be fine for whatever route you decide to proceed with.

I went to my local NAPA store and purchased a 24" exhaust pipe section (flared on one end as you previously stated) and a exhaust tip that points down just like the OEM tail pipe section that came out of the resonator. Looks like we are good to go when he arrives in Florida. Thanks for all your help, I really appreciate it.

 

[sirjr]

I went to my local NAPA store and purchased a 24" exhaust pipe section (flared on one end as you previously stated) and a exhaust tip that points down just like the OEM tail pipe section that came out of the resonator. Looks like we are good to go when he arrives in Florida. Thanks for all your help, I really appreciate it.

The bumper cover on my 07 TBLT is OE. If you dont want a straight pipe coming out of the rear, you can do a sweeping exhaust pipe that exits behind the rear tire, or just keep it simple clamp on a 90° turn down pipe. Exhaust clamp will be fine for whatever route you decide to proceed with.

Our pipe going into the resonator was 2-1/2" OD. I purchased a exhaust pipe reducer/coupler 2-3/4" ID to 2-1/2" OD. The 2-3/4" end clamped to the cut off end and then we clamped a turned down (2-1/2" ID) exhaust tip to the other side of the reducer/coupler. Worked and functioned well.
Thanks again for the pictures and advice.

 

[dmanns67]

Our pipe going into the resonator was 2-1/2" OD. I purchased a exhaust pipe reducer/coupler 2-3/4" ID to 2-1/2" OD. The 2-3/4" end clamped to the cut off end and then we clamped a turned down (2-1/2" ID) exhaust tip to the other side of the reducer/coupler. Worked and functioned well.
Thanks again for the pictures and advice.

Glad everything worked out for you. Did you happen to take any ?