My current axle back mufflers are Borla Ataks. The rest of the exhaust is stock. I am getting some drone with these in 5th gear between 55-60 mph. Curious to know if the FR500s do the same? Also, do these sound similar than the Borlas? They seem to be slightly larger. I'd honestly like to quiet it down a tad but think going to the Bullitt muffler may be too quiet. Trying to listen to exhaust videos on my crappy laptop isn't working too well. Thanks for any help!!