My reason for bringing this up is the turbo seals and engine seals within the motor will have to deal with the pressure and from what I read pressure in the crankcase can cause oil to pass through turbo seals, blow out engine seals, lose of power due pressure in the crankcase causing rings to not seal as well. etc. Now I have my PCV vales deleted to stop the oil in the plenum which means I'm relying on the top of the valve covers for ventilation and when I saw the size of them I thought seriously, I've never seen vents this small. Now you might be thinking well don't delete the PCV vales on the side of the valve covers. Problem is the allow oil mist because of their location and plus in hard cornering oil will "slosh" over the baffles and the motor smokes like a 2 cycle. So for that reason I purchased and installed the PCV delete. Then as I mentioned above I happened to se these restrictors and thought I have to see if anyone else has modified them to allow for beetter breathing.