RB25DET runs very lean

[DrifterProdigy85]

So ive been having this problem with the car losing power when going WOT. Today i installed my wideband and took it for a drive. With stock 43psi fuel pressure, the car was running 16.0 @ cruising and 13.0 @ WOT. A good guess would be there was some detonation and the ECU was pulling timing. Went back to the house and increased fuel pressure to 50psi. Richened everthing up and AFR went to 14.5 @ cruising and 11.5 @ WOT. Its raining so i havnt gotten any solid pulls with the car but it spins like crazy through all rpms now. My big question is, my setup is all stock with a Walbro 255 pump and Nismo FPR, why is it running that lean on stock fuel pressure?

[DrifterProdigy85]

Gotta correct myself. Its a nice day out and got to run the car WOT to redline and here is what i found. At 43psi of fuel pressure the car starts lean around 13.0 and after 5500rpm it richens itself down to around 11.0-11.2. Im suprised at how the stock ecu is setup. I just took the fuel pressure and dropped it down to 39psi and it runs pretty lean crusing around but WOT is around 11.5-11.7 after 5500rpm and doesnt hesitate anymore. Im pretty sure that next thing im doing is going Power FC for some good tuneability for this thing. A good idea for anybody with a rb25 is a wideband. It makes it so easy to sort out any problems with the engine.