Removing the resonator -Pros, Cons & Advise

[FrankCastle]

I know this thread spans over some time, but I wanted to put in my $.02, for the next person who searches.  I had a Magnaflow muffler #12229 (single in, single out, 14") put on, and originally left the resonator on.  It sounded good, for the $100 I spent, but I was curious about how much better it might sound without the resonator, and would that add drone at highway speeds?  Well, I recently took the plunge and had the resonator cut off (but I kept it, just in case) and a stainless steel tip put in its place.  I am beyond thrilled with the low growl that I get in town, coupled with the fact that at highway speeds there is no noticeable drone.  Radio off, on the cell phone is the best test for me.  I even put it to the test with the windows all open, in town, with my wife in the truck trying to talk to me.  Not only were we able to talk, but she LOVED the sound of the truck. 

I couldn't be happier with the Magnaflow.  I couldn't be happier without the resonator.  All for a grand total of $200.

[Frank07]

OK...finally removed the resonator.  Sounds awesome.  Just enough growl with the FM 50.

[avalonandl]

I believe Travelingman had this done to one of his AV's in TN.  I don't recall there being a problem and I thought it did give it a "close to flowmaster" sound.

On the flip side of that, a few weeks ago I had new tires put on and asked the shop to price me a flowmaster catback system ($700).  I made the comment of just cutting off the resonator.  They said it would mess up the 02 sensors and make the check engine light remain on.

I'm doubting this but yet it stopped me from breaking out the sawzall   

That is crap, resonators will have NO effect on O2 sensors- they mean the catalytic converter.


Avalon

[muffman]

Good call Avalon on the O2 Sensor, you are absolutely correct.  I just removed the whole system on my 2010 LTZ yesterday, installed the single in, dual out Magnaflow 5 x 8 x 24 with two 2 1/4 inch tailpipes.  The AV has a nice smooth sound now, absolutely no resonation or droan, and seems to have a little better throttle response.  I may try the 18-inch next week to see what the difference is.  I'm baffled (no pun intended)  by the use of the resonator on the stock system, I really don't see the need.  I noticed on the 2010 the addition of a third catalytic converter compared to my 03.

I certainly wouldn't hesitate to cut off the stock resonator.

Muff

[Frank07]

I cut my resonator out in June.  No issues whatsoever.

[avalonandl]

Muffman- The resonators were primarily installed to handle the DOD  (displacement on demand) resonance  and overall noise reduction. When the V8 goes to V4 there can be low Hz resonance that is annoying- remember this is at highway speeds only. The Pontiac G8 has an enonomous amount of mufflers and resonators to handle this on the 6.0 V8- way more than necesary.

Avalon

[muffman]

Avalon,

I'm fully aware why the "resonator" (not resonators) were added to the AV.  However, in my testing, I find this to be overkill.  This resonance is easily eliminated by implementing two smaller diameter tailpipes, rather than one larger tailpipe, and the use of the proper performance muffler.

DOD or not, the 6.0L motor has always had much worse resonation than the 5.3L.

Muff

[black_magic]

Avalon,

I'm fully aware why the "resonator" (not resonators) were added to the AV.  However, in my testing, I find this to be overkill.  This resonance is easily eliminated by implementing two smaller diameter tailpipes, rather than one larger tailpipe, and the use of the proper performance muffler.
DOD or not, the 6.0L motor has always had much worse resonation than the 5.3L.

Muff

So, what you are saying is two exhaust tips will be quieter INSIDE than a single 3"?  Good stuff!  I was actually under the impression that the dual tips would actually be louder.  Learn something new everyday.  Does the muffler need to be a dual out muffler or can somebody who already has a single-out muffler add a "Y" to their system to help with the drone?

[JLUTTY3]

I have an 07 Avalanche with a 5.3. I drive 12, 14, or 17 hours at a time 8x a year, and take it on sales calls. My truck is a weekend warrior/ grocery getter most other times.

"Everybody" says the stock, quiet muffler can is keeping me off 2 more mpg on those long highway trips. 

I am about to install a clean tube to the air box and an aftermarket element.

I am thinking of putting on a 22" magnaflow for mileage and a slightly deeper tone AND keeping the resonator tip to reduce noise fatigue during the long highway trips. I love the growl. I hate the interior resonance.

My question is, what is the design of the resonator? Is it a pass-through perforated tube with wadding around it, or a baffled chamber?

This would answer my question about flow. I would like to keep it if it's just a pass through. if it's not, I might end up going with turbo- style muffler and no tip.

[FrankCastle]

My exhaust guy (owned an '07 Av himself) said the resonator, whether on, or off, would have no measurable effect on mileage or performance, to speak of. He said it would only give a little more sound. I commute daily in my '07 5.3 and maintaining 80mph with my 14" Magnaflow, I have no resonance in the cab. My $.02

[JLUTTY3]

My exhaust guy (owned an '07 Av himself) said the resonator, whether on, or off, would have no measurable effect on mileage or performance, to speak of. He said it would only give a little more sound. I commute daily in my '07 5.3 and maintaining 80mph with my 14" Magnaflow, I have no resonance in the cab. My $.02

Did your exhaust note change? Is there a video of what yours sounds like right now on line?

Thanks for the reply!

[FrankCastle]

It got a little louder, maybe deeper. I had left it on for a while, but just wanted more growl. I was very ploeased with the final product. I don't have a video up of it. I didn't want to use a cell phone to do it and done have a decent video camera for that.