I've seen two types of airfoils, the one that clips to the TB and the other that has a screw and a piece you place inside the TB. I have the one with the screw, and I'm wondering if that is stopping my PCV vacuum.

 

get the screw in for the TB, better yet save your money and buy my brand new in the box Holley 58mm billet Throttle Body , pm me if you're interested. The one that clips in is a PIA to get right if it's what I think your talking about.

 

Bah!!! The clip one isnt that bad. But in all honesty the Airfoil is a waste.

They say it gains on the dyno, but that could have been cooler dyno room, or changed oil or an act of god.

Save your money.

 

well i've already had it (the screw and nut type), but I think its blocking my pcv because I've got no vacuum. Anyone run into a similar situation?

 

I have the same kind of airfoil and noticed the rubber gasket under the TB cover being sucked down. I took a file and cut a couple of grooves into the top part of the airfoil allowing air into the chamber.