so after rereading this thread yet again, i have noticed others describing a fluttering. is this the surge folks are talking about? i am only hearing it during shifts or letting up on the throttle. it is not happening while under boost.
also, what is the consensus on the drilled vent hole? i used a 1/16" (.0625) jobbers drill, and glued a piece of felt like material over it... though others are saying they used a 3mm (.118") and other are saying they used the drill that came with their 1/4-20 tap, which is probably a #7 drill (.201") that is a huge variance in sizes! would using a difference size vent hole essentially "tune" this mod to work differently?