$14 invested......ok,another $40 for a TrueFlow filter. Took about an hour.
I'll be doing accurate testing with the deckplate over the next several tankfuls as my driving habits change very little.
Right now with the bigger tires @35psi I'm getting and a little heavy on the gas I'm getting right about 17mpg.
You do get a bit of a growl but nothing like the "roar" from removing the fender mounted silencer on my friend's '00 Integra Type R.
It's really only noticeable under WOT and so far I seem to have a little more midrange but not really faster and 7whp isn't going to be noticeable.