Catch Can Routing Turbo/Procharger (Tired of BS)

[Bigfat74]

Any help with a catch can routing????? Used to have two breathers on car with the manifoild plugged behind TB. Now I have line from turbo to diverside valve cover, and passenger side valve cover to inlet of can and outlet to maniflod that i uncapped. Now car ides high, cap manifold car idles correct. I'm lost people tell me car needs tuned, other people tell me it doesn't. I'm tired of the finger pointing.

CAN ANYONE HELP OUT??????

THANKS

 

[z06psi]

Valve covers should always go to a constant vacuum source. Constant vacuum is always in the intake tract before the blower/turbo. Do not hook them up after the boost source as you introduce boost into the crankcase. That's bad.

 

[Voltwings]

I like to rig up kind of a "dual purpose" catch can system, because i agree ^ The crankcase should be under vacuum during daily driving.

Hook a line from the intake manifold to a sealed catch can with a check valve that will close when the IM becomes pressurized.

Hook another line from the sealed can to the passenger valve cover with a T in it.

Off the T'd line, installed a check valve that will close when the system is under vacuum.

This set up will pull a vacuum through the sealed can and operate exactly like stock when in vacuum, but will switch check valves and vent the CC as soon as the system becomes pressurized. Now, the driver's side is the tricky part. Some people will just route the driver's side to the vented can with no check valves. Note, if you do that, it is very important you still have the PCV valve installed in the passenger side, because it will act as a flow limiter for the un-metered air coming in the driver's side valve cover. Yes, i said un-metered air. You still want fresh air coming in the crankcase for the PCV to actually function, but if you hooked the driver's side up to the air intake, then the intake would be pulling in un-metered air through the system when WOT, which is worse. Typically its just a matter of a very minor MAF cal to compensate for this set up. The alternative is to just cap the driver's side and let the passenger side vent the pressure.


Option two is two sealed cans, one between the passenger VC and IM like stock, and one between the Driver's side and intake with another series of check valves where the passenger side can functions for DD, and the driver's side pulls a vacuum on the crankcase at WOT. There are a lot of different options when setting up a catch can set up, it just depends on elaborate you want to get.