i would like to put a breather on the valve cover and close off the hose to help keep blowby under boost out of my turbo and so on, but basically if i vent the crankcase with a breather under vaccum condtions the intake plenum is now pulling in un metered air that used to be metered by the maf, this would now be a vaccum leak and would mess up the tune, i dont see why nobody brought this up, please any help id appreiciate

 

everyone else doesn't seem to have a problem with it.

 

ive tuned cars and having a breather on one side only created a vaccum leak that thru the fuel trims off, i just want to know if it has the same affect on these cars

 

Never heard of such a thing - many Evos use it.

 

im looking for a definate answer, anyone?

 

I dont think it will effect your tune - unless your engine is nearly shot we are talking about a small amount of air

 

im curious, these car have long term and short term fuel trims like domestic cars?, when i tryed a breather on my ls6 motor the fuel trims would change 3 percent adding fuel cause it saw the breather as a vaccum leak, then i just did away with the pcv all together, do you see any problem with this motor having breathers on valvecover and no pcv system at all? i understand ring seal may be comprimised in vaccum condtions but id like to do away with the pcv if i can