[HiFlow5 0]

I have a MAC TB and it only whistles when I moderately accelerate at about 1500 to 2500 rpms. Never had a problem at idle. I have heard that some aftermarket TB's do whistle. I'm not too sure about that whole drilling a hole in the butterfly of the TB. I t just seems like it would cause more idle problems. Plus if an aftermarket TB were meant to have a hole drilled in it, it would have been done so by the manufacture.