Hello fellow G owners,

I drive a '13 G37x sedan and recently removed the OEM mufflers as the first step in my process of building a custom exhaust. I had the exhaustshop cut off the stock piping up until the OEM resonators and welded on a larger 2.5” steel pipe that leads out to the exhaust tips.

The problem right now is that I’ve lost the low deep tone that I heard when it was just the muffler delete with no upsize in piping. The drone is so loud at 1500-3000rpm that it mutes the aggressive tones of the VQ. Not to mention the slight drone cruising at 75-80mph. My understanding is that the OEM resonators are designed for the smaller stock piping, and the upsize in piping has distorted the flow of air/pressure, causing the drone I am hearing. My goal is to eliminate as much drone as possible, while retaining a low deep tone in the exhaust.

My next step is to replace the OEM resonators with a pair of Vibrant ultra quiet resonators. However, as I read more and more about different custom exhaust set ups, I am beginning to wonder if I should perhaps replace the OEM resonators with chambered mufflers instead, or even keeping the OEM resonators all together, and just welding a pair of mufflers to the 2.5” piping. Will either of these alternatives provide me with the deep growl that I am looking for while removing the drone I am experiencing?

Would love to hear any input from exhaustenthusiasts or anybody that has gone a similar route with their G37.

Thank you!