Thanks Jake, nice job.
I have always been confused about the “resonator” nomenclature used in forums. I understand the difference in function to a resonator (eliminates certain frequencies) and a muffler (reduces frequencies across the spectrum). What everyone calls a resonator behind the downpipe does not do anything about unwanted frequencies (drone) and when bypassed the system gets louder. So it functions as a muffler, Volkswagen calls it a muffler in their documentation, yet everyone calls it a resonator. I don’t get it, but who am I to buck the forum masses.
Unfortunate to hear that the Vibrant Performance Ultra Quiet is not up to the task. The resonator (which actually is a resonator) on the stock downpipe works well and is 10” in length, same as the Vibrant UQ, and similar diameter; therefore, with similar internal volume I am surprised to hear that it doesn’t work well.
So much of this depends on your design goals. Yes, most folks want to get rid of the sound that makes your head feel like it will explode when you are at 3.3K going up a 7% grade. In my case, I am trying to get rid of drone and keep it as quiet as stock as secondary goal. So if you remove the first muffler (resonator) to put in an actual resonator you get rid of drone, but then the system is louder. If you use the 18” longer resonator there is not enough room to put in between downpipe (cutting downpipe near bracket) and muffler (resonator). So no drone, but louder system.
I hope the Vibrant UQ works well enough as I have limited space to work with for what I am trying to accomplish; that and I have one waiting to install. First place I went to install did not believe there was enough room to install before muffler (resonator). If you use the 4.5” of pipe going into the muffler (resonator) and cut downpipe at the bracket I think it can work. Some of this depends on downpipe as mine (Eurojet/Revo) is offset from center at bracket. I will be looking for another installer as I haven’t given up yet. If that doesn’t work, I intend to remove muffler (resonator) and install resonator and a Flowmaster DBX muffler. Unfortunately, if I use the larger 18” resonator I won’t be able to use the additional muffler. Compromises sometimes have to be made depending on what you are trying to accomplish.