Ok, a wideband O2 sensor indicated that I'm running very lean (about 13.4 @ WOT) at ~6500 rpm. This was with my fuel pressure at 58psi and my VAFC cranked up to +18 (any higher made no difference -- maxed out). It looks to me as though the stock system just isn't enough anymore. How should I appropriately upgrade my fuel system? I plan to get the Skunk2 ecu which runs rich, but I am still wondering if I'm over taxing my fuel pump and injectors.

My mods:
- Skunk2 cams w/ gears at +3(in), -2(ex)
- Skunk2 IM
- DC JDM header w/ Carsound cat and Tanabe exhaust modified to complete 60mm ID
- ITR AEM CAI
- VAFC
- B&M FPR

Note my timing is at 18 degrees and my engine has always been on the strong side relative to other B18Cs.

 

ttt

 

13.5 isnt really lean. Past 14.7 is lean.

13-13.5 is about where an NA car should be.

My suggestion is to do a pull on the dyno and shut the motor off immediately
after hitting redline. Then check the plugs. That will give you a better estimation.