Boost gauge is reasonably easy to install - tap into one of the vac lines on the manifold and T off a line to the gauge. Just dont mistake one of the larger coolant lines as a vac line.
Dual stage Boost controller is pointless - They work by fooling the ECU into thinking things are normal when the controller is making changes. The subaru system is different, and you'll end up with check engine lights etc.
Raising the boost is also pointless - the turbos on these are very small - and as such are running very close to their efficency limits - increasing the temperature of the inlet charge is a great way to introduce knock to a system that has a hard enough time dealing with it anyways.
I take it by the 'add a bov' you want to change the standard one for a vent to atmosphere one? This is easy to do, but you'll have to do some research on what aftermarket models will fit on the standard position.
As per Jimbos comment - read the TT thread before touching these cars mechanically. They are finicky and dont like being fiddled with. Plus, the later model TT models were renowned for doing big end bearings stock, let alone fiddled with.
Now, without knowing the specifics of your car, all I can say re overboosting it is that the stock Gen 3's boost settings are within about 5psi of boost cut (well, effectively fuel cut in the early models). so any gains you put through are going to make negligable difference to your 'seat of the pants' power gauge. Plus, all it takes is a freezing cold night and its extremely likely you'll hit it by even upping it by a few pound.
Have a read of the above mentioned thread and see what you want to do then. Sorry for the bad news, but certianly do some research before fiddling fellas.
Its not a simple thing to just throw a boost controller on it and up the boost. Talking major upgrades before you can get decent power increases.
The dead spot you're talking about is commonly referred to as the 'Valley of death', and you are half right - its where the valves in the system start opening on the secondary side to get it spooling up. As a result there is a substantial drop in power as the primary can't keep up with the exhaust outlay of trying to spool the secondary. When the VOD is over, both turbos are working fully. It can be modified, but you are better off reading the TT thread before you change anything.
Cheers,
Ben
MY00 Red RX, a nice daily that was sold off once the B4 became reliable...
MY02 Blue B4, aka 'The Project' - v8 JDM STi engine package and assorted other 'goodies' - Sold, then bought back for parts. Stripped and crushed.
MY03 Blue RX, the newer old daily, pretty well more B4 than RX now... In the process of being converted to the track toy... Watch this space!
MY02 Silver Wagon, H6 conversion, full blue/black leather and almost full black interior to go with it.
MY03 White/Silver H6 Outback, donor car for silver waghoon.
MY97 Silver RX, acquired to become track car, but plans changed. To be stripped and scrapped in time.
