I have been out of the nissan world for some time now, and have forgotten many things related.

I have a friend who built up a NX2000 with a rebuilt U12. He plans to run no more than 10lbs of boost. He invites me over for first start up. Car starts and sounds great. I check afr and they are a t 12.5 at operating temp.
I asked "what management are you running?" He says "Factory ECU, PLX Wideband and 550cc Bosch injectors"

Now I ask the forum.

Can factory ECU run a U12 without a stand alone or piggy back system without the use of a fpr or rrfpr?

I know 550cc injectors are too large for this ecu, So I need to know what size injectors can this ecu handle? Also he switched the injector plugs to bosch style connectors and need to know what bosch injectors to use. low impedence or high impedence?

Stock ECU with 550cc will run VERY rich. He needs a JWT or Calum ECU.

What about throwing smaller injectors in, say some 370cc but by bosch?

A stock ECU is programmed for 259c injectors, and nothing else.

Thats what I was looking for.

I work on bmws and a lot of them can accommodate for larger injectors to a certain point. For an example a E36 325is have 19lbs and can adjust up to 30lbs no problem.

I was just curious if a b13 ecu can do the same.