Originally Posted by
Karlos G
Boost has nothing to do with your breather system unless you have no piston rings..... which in this case it does sound like Sean!
135psi is shite, even 150psi isnt great maybe on a 80k engine you'd expect to see that sort of reading.
I would say your pressurising the bottom end because of ring/bore wear and forcing oil out your breather system.
Boost does have a direct effect on the quantity of blow by that occurs. If we had no blow by then we wouldn't need a breather system at all and if boost pressures had no effect on the breather, there would be no reason to fit an uprated breather oil seperator and catch tank. Been there and done all this research before, 10 years ago.