I have some question about the fuel system on the 5.5 gen maxima.
Base fuel pressure is 52 psi on the 5.5 gen max and the fuel pressure regulator is in the tank. The system is returnless. I am upgrading the fuel system to run boost and the first step was getting a walbro 255lph fuel pump. I am going to keep the fuel system returnless but will i need to put in an additional fpr in-line or will the stock one be fine? And what else should i consider if there is anything? So far i got the fuel pump and bigger injectors and utec is on the way. thanks

 

The way the stock FPR regulates the fuel it does drop excess fuel back into the tank. Its just my opinion and its worked great for me, is to convert to return style and mount an aftermarket Adjustable FPR under the hood. If done right you shouldn't have a problem with fuel when you go boost.

 

Firstly check out the my350z forums for some good info on your fuel setup.

As far as I remember, you need to remove the stock FPR and replace the stock pump with the walbro, then install an aftermarket FPR and run the return line out of the FPR back into the tank if you want to keep your fuel system as stock as possible. There is supposed to be an easy spot to tap the tank for your return line, I am pretty sure I found a good thread about it on my350z.

Otherwise, you can tap the damper on the other side of your fuel rail and run a return line from there with the FPR installed on that line and have a return system.

If you want to spend a ton of money on it, there are several companies that make full return systems that are quite easy to install for the 350z that should fit ours fine.

 

As of now I would like to keep the fuel system returnless. I was just wondering if i could get away with just replacing the stock fuel pump ( which i did ) with the walbro and putting bigger injectors in and leave the rest of the fuel system the way it is.

 

Yea it will work the rest would come with tuning.

 

I've been told the stock FPR won't work with the walbro to get stock fuel pressure by other members of this forum, have you tested this for sure?

 

it will work but in makes no sense to keep the stock fpr, yes i tried for about a week before my aeromotive came in.

 

What is the disadvantage of keeping the stock fpr and the the advantage of going with an aftermarket unit if the fuel system is left as a returnless one?
Also what model of the aeromotive did you purchase?

 

the disadvantange is no matter what fuel pump you use your fuel pressure will always be set at 52psi. you want a 1:1 AFPR for every pound of boost your fuel pressure raise 1 psi. The model I have is the aeromorive A1000-6 13109 with -6an fittings