MagnaFlow exhaust drone

[Ijg4503]

Hello fellow ZR2 owners....... Looking for your advice. My situation: The previous owner of my ZR2 installed a MagnaFlow muffler and removed the flapper. The truck has a VERY annoying drone at mid to highway speeds and it is bad enough, that a lot of times Siri cannot understand what I say when I use the hands free talk to text. Any recommendations to help eliminate the drone (the stock resonators are still there)? I will not invest in an entirely new exhaust system on this truck.... especially with the 6.2L issues, transmission chatter, and recent various recalls. Some ideas/options: 1) Find another aftermarket muffler that will not create the drone, any suggestions would be much appreciated! 2) Find someone that is selling just the OE muffler & flapper assembly. 3) Purchase the right side exhuast pipe assembly that includes the OE muffler. Per my local dealership, the muffler and collar only GM Part # is 85537498.

Any help/advice would be appreciated!

Jason

 

[AXE]

That's not the Magnaflow system that is designed for the ZR2 6.2L motor. It is a generic muffler that can be welded into any exhaust system. The Magnaflow system has a separate resonator parallel with the muffler in addition the stock resonaters. I have a detailed thread on that system I bought from Hottexhaust.com for $600. It'll slpice right in if you remove that can you already have

I think others have posted about the Borla touring muffler that will replace that one. It's less aggressive sound.

 

[TexOffroader]

Another thing that worked for me was to install a 3rd resonator after the cat just before the muffler. I had terrible drone in the cab from my Borla Atak (despite Borla advertising my muffler as no drone, LOL) and just couldn’t tolerate it any longer. I also have the flapper eliminated. I think the stock resonators are too close to the tips to make much of a difference in the cab. Cost me under $200 parts and labor. I did loose a little rumble during cold starts and lead foot driving but I am much happier in the cab.

 

[MAXIMUS]

Another thing that worked for me was to install a 3rd resonator after the cat just before the muffler. I had terrible drone in the cab from my Borla Atak (despite Borla advertising my muffler as no drone, LOL) and just couldn’t tolerate it any longer. I also have the flapper eliminated. I think the stock resonators are too close to the tips to make much of a difference in the cab. Cost me under $200 parts and labor. I did loose a little rumble during cold starts and lead foot driving but I am much happier in the cab.

I’ve got this same setup too. What resonator did you get to eliminate the drone?

 

[TexOffroader]

I’ve got this same setup too. What resonator did you get to eliminate the drone?

Just posted a similar response on another thread. Local muffler shop had a used GM resonator that came off another vehicle. It does not have to be the same resonator that GM installed on the ZR2. Find a local muffler shop around you and they can advise assuming they’ve dealt with drone before. My guy was confident before starting the work and he was dead on.

 

[MAXIMUS]

Just posted a similar response on another thread. Local muffler shop had a used GM resonator that came off another vehicle. It does not have to be the same resonator that GM installed on the ZR2. Find a local muffler shop around you and they can advise assuming they’ve dealt with drone before. My guy was confident before starting the work and he was dead on.

Roger that. Thanks for the advice.