Since installing the sport accessory muffler and letting it break in, it's hard to ignore the rasp around 3k rpm when accelerating quickly. The muffler sounds great when I'm driving normally. I had zero rasp with the stock IPL muffler and RHFC, but I could only hear the intake when driving fast. I'm contemplating options... Rest of the exhaust is stock IPL. Would there be any improvement if I swapped stock resonators with, say Vibrant 18"? Stock coupe size is 12". I still have the stock muffler in case I get old and get sick of the noise. Not sure how ridiculous it'd be to add a second set of short resonators either.

Edit: Oh yeah, I also get drone at 80 mph on the highway with the new muffler.

 

The Vibrant Ultra Quiet Resonators are definitely a nice piece for improving exhaust tone. It does help get rid of some of the rasp as well. I haven't tried any of their other products so I can't comment on those.

What kind of piping do you have between the HFC's and the sport axlebacks?

 

Stock IPL. I'm just wondering if they're that much different than stock.