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.