[Dave80GTSi]

Easy, now, take a deep breath …

About a month ago bought and installed a set of the Circuit Werks "resonator" mid pipes. Pictures below.

I don't think that the "resonator" portion of these pipes does all that much, as you can see that it is a straight-thru design. So there is very little flow restriction offered by the "resonators". Which also means that there's not a whole lot of acoustical benefit to be offered by them, either.

Without doing a back-to-back A vs. B comparison between these pipes and their straight version, there's no way to note if there is a genuine acoustical difference between them. I simply selected this option as I wanted to try to see if I could take a bit of an edge off of the resulting unrestricted sound.

If you are using an OEM muffler, my vote would be to use the straight pipe design as these stock mufflers seem to have more than enough restriction for two cars. But if you are going to an aftermarket muffler (as I did), then I would vote for using the "resonators". Can't hurt.

DM