When it comes down to making power in your B58 powered vehicle the pcv system is taking the beating of the century. BMW integrated the pcv system with the valve cover(internally) using small holes in the intake runner to operate the diaphragm thats built into the valve cover. Well this is where its brittle and needs to be addressed. This PCV modification kit does just that. It isnt necessarily a PCV delete kit because it retains the PVC function at idle and no boost cruising. Once youre in boost the VS PCV Upgrade kit's built in check valve kicks in and keeps boost from entering the valve cover aka crank case system. This eliminates any possible boost leak going into the valve cover and retains OE functionality when you need it. this is a MUST have for anyone with upgraded turbo or ST kit.

This is different than the VS - Headport plugging kit since that kit permanently deletes pcv completely. great cheap alternative if you dont care about the pcv but the VS PCV upgrade kit is better since it uses vacuum to help seal the rings at idle.

These get pressed into the valve cover as shown in the picture.