I'm just now bringing this car back to life after many years of sitting in the garage, and the PCV system was setup in the stock configuration which is definitely wrong for boost. I'm running a P1SC (speed density/no MAF). Here's a diagram of what I've done. Is this routing insane? I definitely get more crankcase smoke/vapor from the breather under boost than I'd like. Years ago, my old Paxton setup had tubes for crankcase vapors to be fed back into the vacuum side of the supercharger, but I'd really rather not do that with my Procharger since oil would get all over the inside of the intercooler(not to mention general crud getting all over the impeller). It may be wildly unrelated but other variables I'm tracking are: making almost no boost (~3lbs) and lower than expected oil pressure(~30lbs).

catch can / check valves for PCV / boost


passenger side catch can

driver side PCV with additional inline check valve

 

Do you even need a catch can? Unless the rings are spanked, or you are running high boost pressure (30+ psi), we generally don't recommend them at all.

Under boost the PCV valve is forced closed and crankcase pressure is vented through the filtered valve cover..... so are you thinking you are going to have a bunch of oil from the passenger valve cover under boost?

30 psi oil pressure under what conditions? Hot idle? In that case it's fine.

GD

 

I at least needed a vent, and liked the idea of a catch can since it allowed me to move the blowby smoke/oil vapor a bit further away from the valve covers and headers. Oil pressure is actually worse than I said... more like 15psi all the time. Searches indicate this may indicate a sending unit failure. The engine has less than 5k miles on it since new, but that includes a long time sitting. I think the rings should be fine, but I've been wrong so many times before that I figured I'd disclose in case someone knew better. The main thing I wanted to know is if the check valves I added made sense in location and in gas direction. I'm not sure it makes any sense to keep the throttle body to catch can connection on at all for instance.

 

No reason I can think of to suck anything from the catch can into the throttle body. I would definitely delete that and put another filter on that port.

Check the oil pressure with a mechanical gauge.

GD

 

The rationale for the catch can-to-throttle body connection was that it would put vacuum on the breather more quickly, hopefully reducing smoke(which is substantial imo. dirties the windshield over time and just looks janky). Probably a paranoid choice on my part, and I do like the idea of two breathers on the catch can to possibly increase flow when under boost. I wouldn't be at all surprised if it were also the source of a giant boost leak(expecting ~7lbs, getting 3 - but it is _not_ tuned well yet) considering the hacky way I ziptied the check valve into the tube.

Can anyone elaborate as to why PCV connects to vacuum from two separate locations, ie the throttle body and the manifold? Is the throttle body vacuum connection outside of the throttle plates, thereby at less vacuum than the direct manifold connection in order to maintain a difference in pressure between the two valve covers, but overall to lower the delta between them vs atmosphere?

 

The pass valve cover line is indeed ported to the front of the t-body blades. It supplies filtered air to the crankcase that is removed by the pcv on driver side.

 

I delete all that and run breathers only unless its spitting oil then run to catch cans