Its from last year when I first got them installed. They are 18" resonated. I purchased this version because I live in a bit of a classy country club and the wife was not about me screaming everywhere I went. It gives me plenty of noise when I rev it up so im happy. I did however just order from Tony and FI some Resonated Test Pipes so it should increase the sound somewhat but Im happy overall. I get great compliments on my sound nonstop!

I was a little nervous about non res being too loud. Now that I have it, I am extremely happy I went that route. Certain rpm's there is some drone but it doesn't bother me. I think I even wouldn't mind the exhaust being a little louder. I'm on stock cats btw. YouTube videos definitely don't do the exhaust justice. Sounds much better in person. I sent friends before and after videos taken with my gopro and they say it sounds the same. Then when they hear it in person it blows there minds.

late in on this thread, but I think part of the decision making is auto vs manual..

I went auto.. and for that reason.. Im glad I went 18" res. when I rev it.. its exactly what I wanted.

its is drone -ish abit..at 1900-2200 rpms though.

It all depends on what your looking for. Couple of questions that will help me give you better advice. How old are you? Is your car auto or 6mt? Do you do a lot of highway driving? Is drone a concern?

Edit: Just saw you have a Nismo so scratch the auto/6mt question!

TerribleONE thanks for your reply. I've made my mind couple weeks ago to go with 12'' with NRHFC.:tup:Should be fun

How will non-res test pipes affect the sound of 18" resonated cat backs?