I am running the Greve pipe and see the same db's as Troy on a full throttle 16.5x12W. If I go to the 16x13 and get it around 8100 I get the noise down to 91 dB's.

It does have a little bark to it, but its got soo much power that you dont really care if you back it off a couple hundred rpm

Like Troy said if you want some screamin' vertical the 16x12 will make you very happy I had that on my Evolis (9.4 lbs) and the power was just plain stupid :stupid: but fun