walbro 255 fuel pump

[95gstproject]

If I upgrade to a walbro 255 fuel pump will I need to get the apexi afc yet I still have stock injectors?

 

[G50trim92]

No, you don't need one, but you could gain a little hp with it.
Check out Ryan Dao's car on the sight in my sig. I don't know if his mods page is updated but he used a s-afc with simular mods as you to get to 13.0 # 103. He also has a 14b.
I'll see if I can get him to comment on this for you.

 

[brokeawd]

Something you might want to check into with getting the 255 HP is gettin an adjustable fuel pressure regulator from www.spoolinup.com my 255HP was overflowing my stock regulator and not making the fuel curve linear. Your supposed to raise 1lb of fuel pressure per 1 lb of boost, My fuel pressure at idle was at like 51, its supposed to be 38 with the vacuum hose off.

Ive heard some cars are OK and some other arent. Just a suggestion

 

[95gstproject]

I have the b&m adjustable fuel pressure and it set a 40 should go to 38?

Thanks a lot

 

[BatmanGSX]

If you have a Command Flow you cannot lower the base fuel pressure.

The only thing you need to worry about is the pressure being at stock levels (or close to it) and making sure it rises 1:1 with boost. If your pressure does that it doesn't matter what pump you have, you will still get the same volume of fuel at the same IPW.

The only reason to ever get a new pump is if the one you have can't flow enough volume. This is easily shown if your pressure drops off. If you are running 40psi base pressure and 20psi of boost your fuel pressure should be 60psi once the turbo is spooled up. If it starts dropping you need a new pump. Once you do a need a pump you may as well go as big as possible, provided you are also willing to get an AFPR. Additional volume just goes back to the tank, no richness will occur.

Monitoring fuel pressure is good.