unless you already have a stash of parts handy probably work out cheaper to buy something like this
with the pressure sensor included
ive no idea what sort of pressure in crankcase were looking at ? maybe a couple of psi at low loads and then maybe double figures psi for those of us running high boost pressures depending on engine condition and ring sealing etc.
but with the breather working we wouldn't see this amount of pressure ?
also vac at the turbo inlet pipe would be nice to know or is it the same pressure at different places in the breather line ?
I may run parallel tests to you I have some breather hose, so I can knock up a t and test at my catch tank and temporarily run to a gauge.
o.k run a couple of tests with a gauge t'd into the level pipe of the catch tank so pressure vac at the catch tank only for now.
psi gauge didn't move if at all
pa gauge showed 190pa pressure at idle, if reved went off gauge
switched to a kpa gauge and at idle buzzing around .2kpa and gauge goes to 1.0kpa so ok for now
as soon as car is loaded up or accelerating pressure dropped straight away to 0
so switched in and out so now reading negative / vac
now under slight load constant acceleration or cruising with 0 boost showing catch tank now showing approx. -0.2 to-0.4kpa depending on revs and gear etc.
if slotted into high gear at low speed ie off throttle cruising dropped to zero(probably + .2kpa or 200pa as shown above)
now on boost depending on load and gear again I was seeing a steady rise of vac with boost upto off the gauge at 1.0kpa which although hard to watch and drive was somewhere around 10-15 psi boost = negative 1.0kpa of vac at catch tank.
ill have a dig around to see if I can find a higher gauge to catch vac at highest boost.
but for now should give something to base your equiptment on
looking at converting 0.2kpa = 0.03psi
1.0kpa= 0.145psi = approx. 4 inches water
so forget a psi gauge.
so if you have no gauges a simple manometer of clear tube into a bottle of water connected to your test points may be good enough and expect it to pull up the tube more than 4 inches .
these figures will change depending on turbo size, 4 cyl vs 5 , maf and airbox restrictions etc.