Update:
I had my car dyno this past Monday and all the changes to the wiring harness at the fuel pump paid off. The LS3 350Z is making 441WHP with 415 wheel torque at a steady 60psi of fuel pressure. I installed a 40 Amp relay that's to be activated by the signal coming from the PCM when the car is on. Power is sent through a 12AWG wire directly from the battery. At the pump, I replaced the OEM controller with well nuts and using a 14AWG harness to link it to the Walbro connection to the pump. So no more issues with fuel delivery. What we found out during the dyno runs is that the Mass Air Sensor is getting too hot because of its proximity to the radiator and fans. Looking at relocating it but, other than that, the changes were a success. Here's some pictures.

Relay with power coming from battery, ground wires, and signal wire from PCM

Well nuts and connection to fuel pump in tank

Fuse

441WHP 415 FT/LBS torque

620LSZ

 

Looks good Julio and congrats!

If I could offer a tidbit of advice. I ran my relay with connecting clips like you and it seemed like I was always short-circuiting the wire one something! Luckily only blowing fuses. I subsequently went with relay holder and I did a bang-out job wrapping my connections. I also found this held the relay tighter than just clip-connections.

 

I'll look into it. Thanks for the tip!

 

Hi, everyone. I wanted to give an update on my car in regards to the fuel pump assembly changes that I did late in the 2019 year to provide enough power to the fuel pump. It looks like the well nuts have failed. Corroded by the gasoline as shown in the picture bellow. A couple of good things: The fasteners didn't come lose thanks to the lock washers, and I found out about this before it could have done some real damage. Now, I'm looking for an alternative. I've been thinking of the Holley Sniper Diecast 340LPH in-tank retrofit fuel module returnless system that they offer as a way to upgrade the limitations of the OEM fuel basket in the 350Z. I don't care about the fuel pump offered with the kit

since mine is a 450LPH pump but, the modular assembly design seems promising to upgrade to a better and safer way to provide power to the fuel pump without drilling holes on the plastic fuel pump basket like I did. I have brain stormed some ways to mend the holes on my OEM basket and use rubber grommets to pass only the wires through the plastic plate at the top but, it feels risky and I don't want my car to catch on fire. I wanted to get your opinions on the modular kit offered by Holley and what you think of it. I've already brainstormed an aluminum adapter plate to seal the OEM hole on the fuel tank, and just cut a 3.25" hole on the adapter plate to fit the Holley modular pump assembly. I'm going to keep researching but this seems like my best option. I know there is a dual pump aluminum basket offered for 350Zs but, I haven't made up my mind about that one yet. Thanks for your input.

 

autosportsengineering.com has a fuel assembly that's for our car and has extra slot for 2nd fuel pump in future if go that route.

 

Thanks for the tip. I actually ordered that one from autosport engineering over a week ago. Just got it in yesterday. I'll update how it turns out once all the other parts I need artive.