Originally Posted by axmea?

Yes, this is the combination that I have. Glad I got the HFC. I figured, he's already going to work on it anyway, why not throw that in. I get the thumbs up at stop lights and when simply driving by at cruising speed.

Tone - Low tone growl at lower rpms, sexy burbling sound between 3k to 4k, roars when you floor it. Best way to describe it -- exotic or excitingly unique. Love this exhaust.

Volume - it is loud when you gun it, loud when down shift at midrange, loud when your at 60-70 mph at 2.5 to 3k rpm at 6 gear, down shift to 5th and she sings with an excitingly unique roar. Shift to 4th and your ears asks for more. It is loud when your next to bus, loud when your next to semi, and loud next to a Porsche. It is loud when you're under a bridge, even louder in a tunnel, which by the way is fun times when you down shift. It is loud when Synchro Rev Match kicks in on the downshift. FI + SRM + Tunnel =

This said, what do think would it be like in the cabin? Take a wild guess. Tony suggested 18's for a <30 % change for in cabin volume.