So heres my story...
ive been reading up on HT about velocity stack design and even made my own at work which didnt come out so bad i dont think for making it out of a scrap piece pulled from the junk bin ( not completely done though). So in the meantime im flippin thru the new Turbo Mag and i noticed the stacks attached to the turbos on this RB powered 240sx have holes in the radiused part of the stack. And im like wtf would those be for?
So my question to u guys is what are those are for? wouldnt that disrupt the air and defeat the pupose of a stack?

Other than being curious i ask becuase MY stack is made out of a scrap piece and has holes in almost the same location in a bolt circle pattern. And if there is no negative affects i wont waste time filling them in.

 

Pics?

 

I'm fairly certain the stacks you are seeing are actually part of the compressor housing, not an attached stack. Those holes will be part of the anti compressor surge setup. It should allow more air out past the wheel during surge (holes go through to wheel I believe).

Of course... that is if I'm guessing correctly what you saw... and if I've understood those housing modifications correctly

 

^^^ ahhh i understand now. Thanks i appreciate the response, this thread is done.