All done and I'm happy with it!
For me, the car was already naturally loud. I recorded sessions over a 30 min ride to work through the Austin TX hill country where you have to downshift to get up some of the hills without lugging the engine and recorded the results. I also recorded results during spirited driving. My hopes was this might help me rationalize what I hear and think to real numbers.
My initial thought was, yes it's louder but not much. Drone wasn't much worse at all. Not deafening or annoyingly loud by any stretch. The exhaust had a clearer "note". Having something to compare to now, I would describe the previous sound as somewhat "held back" or slightly muted. I could hear more of the "thump" of the cylinders might be another way to describe it.
Enough about my opinion though... lol. Here are some numbers from my iPhone app.
With 18" res and stock cats: 85 avg db, max 94.
With 18" res and stock cats during spirited driving: 85 avg, max 97.
With 18" res and FI HFC: 90 avg, 98 max.
With 18" res and FI HFC during spirited driving: 90 avg, 101 max.
No tune yet but I'll post my results when I get them in case someone is interested.
If you think the sound is perfect with stock cats, you might not like the extra volume or tone you get with the HFC. I wish I had a video or sound recording so you could hear the difference in just the tone...
