Changing 4 port blow off valve
 

I am looking to upgrade the piping preturbo on my Move. Plan is to install water injection before the turbo to help keep the pipes and air cooler. The system is speed density, so unmetered air is not a problem. The problem is the hoses. There is one hose from the valve cover to the BOV, one hose from post turbo to the BOV, one hose from preturbo to the BOV, and one hose for vacuum/boost signal. I am a little confused as to what hoses I can or can't keep. I want to delete the pre-turbo connection just to make the preturbo pipe easier to make, but don't know if the valve cover hose is needed or not. Any comments? This is a JDM only car, so the name won't really help. I can take pics if they are wanted or needed.

That is a bizarre one. boosting the base pan for? or is it the other way, base pan setting off bov?

Could it just be a somewhat convenient way of routing manifold vacuum to the valve cover? I know a bunch of older cars do that in order to vent the crankcase vapors into the intake.

it's got a PCV valve from VC to IM, but also has the VC to BOV. I disconnected the preturbo to BOV hose, and had no driving problem, just loud sneezes. Gonna try to find a cap that size and cap off the preturbo line to keep dirty air out. Really noticed the sucking sound with the hose unconnected.

Anyone have any comments on ABS, PVC, or metal for preturbo piping?