it doesn't do it at idle or free rev. and the gsr comp is 10.1:1 which these arias pistons are too. ok, so its not a knock, its a punch of ticks and pings at randon intervals under low rpm load. like i said, i'm not all "educated on these piston terms, since i never heard knock before since if you knock a rotary, you blow it. does anyone wanna make 50 bucks and come out to reset the timing?