Thread: Walbro 255 upgrade

Why do you want to run 4bar?

I run a walboro 255 and z32 fuel filter and the car runs fine. Idk what my fuel pressure is, I'm sure its higher but the car runs fine anyway. Its actually a little reassuring knowing that I'm a tad rich. I don't worry about running lean.

I'm pretty sure I read on here that it can help with gas mileage some. With the mileage I'm getting, I'll try anything! That, and so my injectors aren't maxing out as fast. (Don't know if they are or not, but why push it if you don't have to?)

But, if the fuel pump is going to raise the fuel pressure that much then I suppose I may as well throw the Aeromotive in and actually dial it in to a steady 4bar anyway.

My fuel pressure stayed relativley the same when I installed the Z32 filter today. It actually looks like it dropped by .5-1 psi.



I hear ya on that , I meant why 4 bar over 3 bar? 4 bar puts more pressure on the fuel pump.

It was an inline FPR after the stock one. It was adjustable, but I never messed with it. I set it at 4 bar exactly without vacuum years ago and just never worried about it. Car was a stockish setup, but what I meant is I didn't have a nismo style FPR on it.

My current car uses the nismo AFPR.

I do find it odd though, that I have run the stock FPR and the nismo AFPR and both had nearly identical a/f ratios under boost. hmmmmmm.

I wonder if putting my stock fpr on would cause me to run rich...

^^^ You could always adjust your tune to it if you have a Real Time or a Basic or Nistune. Then no need to worry about crappy Nismo FPR. Hmm this actually gives me an idea....

That is what I figured would happen. I thought the post above sounded a bit off when he said the pressure rose...



True point, I didn't really look at it from that perspective. However, if I put it in there and it makes a noticeable difference to my fuel pressure, then what's another few more PSI gonna hurt at that point to reach a solid 4bar?



This is what I'll be doing once I get the fittings for the Aeromotive.

Yup it went against logic, the bigger the tube the less pressure it will have. Bigger fuel filter means more space for fuel to use up, thus lower fuel pressure.



True true, I guess I'll see how badly it raises the fuel pressure when I get around to installing the the 255lph. The condition of my current fuel filter was horrible, I think I might do a complete fuel system flush...

pretty grim what comes out of the old filters .... bleugh

sludge pretty much came out of mine when I first changed it after importing

kinda crazy to think most new cars don't even come with fuel filters anymore. They just run the strainer/pre-filter for the pump.