I've been running the following spec for a couple of years with the only planned additions being an equal length header plus sports catalyst and yet another remap:

2.5" exhaust and removal of the up/down pipe cats.
Remap,
Samco hoses,

I've no idea what the power output is but it has been running with the standard fuel pump since new, so would I see any benefit in changing to a new Walbor pump?

It's a MY02 Wagon.

 

Best thing is to ask whoever's gonna map it.. some say yes, some say no...... if you might go further with it, then i'd stick a pump on for safety's sake....

 

no need unless you are going to change the turbo

 

The problem with the factory pumps isn't in "normal" use but when they get very hot they suffer from degradation and in extreme cases can't supply necessary fuel where an uprated pump can still work in it's range.
JIM

 

i think you can't outmax the standard fuelpump with 380cc injectors.
For safety i would get an walbro. I see them all of the time on ebay for around $90,--

 

...or a factory fuel pump from a 2.5lt STI that is 145lt/h instead of the 130lt/h (at 300KPa) all pre MY05 WRX/STI use.
Cheaper and factory quality, if that counts!
JIM