Originally Posted by semtex

I would suggest looking in the intake/exhaust section of the forum.

Originally Posted by dalparadise

If you are still under 1000-1500 miles, I'd suggest waiting a bit. I've heard the note deepens a bit by then. After that, it seems like Stillen is the most popular for Zs in general. Most high volume posters here seem to like FI or Berk, though.