15-20 psi on stock internals is pushing your luck, seriously. your gonna hammer the rod bearings, stretch the rod bolts and put some seroius stress on those spindley rods... not to mention push the head gasket out of line and lift due to the inadequate clamping abiltiy of the stock Head fasteners. For this, you need a sleeved block w/ a closed deck, a metal head gasket w/ the block and deck honed to an almost mirror smooth finish and ARP 220,000 psi studs, torqued down to their specs using the Moly Lube. thats a bare minimum... youd also need a forged steel crank and big ol steel rods, shot peened, balanced, weight matched, and stress releived. then you also need ARP rod bolts, nothing less than 190,000 PSI wave-loc's. youre pistons, should be Forged aluminum w/ Ceramic coating on the skirts and crown (the coating is the icing on the cake). and Total Seal Gapless rings are decent... unless you want to just go the tried-and-true file-to-fit rings, then that would be a set of Plasma-moly coated rings from TRW, if they even have a set for your car.
anyhow, a T3-T4 60 trim would suit you just fine. you should see what it can do on 0.5 bar before you try cranking the boost... a new acquaintance of mine, has a Civic, and just blew up his 5th motor cuz he accidentally ran 22 psi on his T3 w/ stock internals, on a SOHC 1.6... you could see the hole in the back of the block, the rod, and the crank... it was a sick sight.
yea, the BOV only makes noise when you shift, and the WG only makes noise when you hit your preset boost levels; untill then, the WG should stay closed. if you recirculate the WG dump, it will be virtually unnotiicable... if its dumpped, man o man... its wicked loud.
I forgot to address this before: Cast manifolds have superior heat sinking and thermal stress properties, especially when compared to tubular manifolds. the Tubulars are pretty and can be custom made for each applicatin, but unless they are properly braced and made of high quality stainless steel (at least 3xx series=EXPENSIVE) or Inconel (proprietary alloy of Stainless/nickel and other metals=SUPER EXPENSIVE). plus, the welds like to crack. ive seen it happen on several nice looking stainless tubular manifolds, that cost an arm and a leg.. i prefer cast just for durability and peace of mind. not to mention, it keeps the thermal energy within the exhaust which puts more energy onto the turbo and makes it easier to boost. Tubular manifolds are thin and give off more heat than cast. think of it like putting a Big fat block-headed Lab outside in the snow, and a Chihuahua; which dog will lose heat faster?
