General 1G Base fuel pressure for 550s?

[New2tuning]

I am trying to figure out the base pressure I need to set my AFPR at for 550s and a 2G maf in a 1G running a 14b. From what I found I think it should be 52 psi without the vac line hooked up, just want to confirm this. Thanks

 

[andymoraitis]

Base fuel pressure on the 1st Gens is 37-39psi. 2nd Gens use a base fuel pressure of 43psi. Both are adjusted with the vacuum line removed. Unless your mod list is incorrect, there's no need to play with fuel pressure at this point if you have a stock fuel pump. By the way, you don't use fuel pressure as a means to correct for injectors when going larger. Bumping fuel pressure is generally done when smaller injectors are maxed on their duty cycles (IDC) and you want to squeeze more volume to them. For 550's, you'll need some form of fuel control (EPROM ECU, AFC, DSM Link, etc) to control them properly.

Hope that helps,

Andy

 

[New2tuning]

Yeah my mod list is not updated. I have a Walbro 255 in now. My SAFC will be here in a couple days I was just told that I needed to adjust my fuel pressure higher before tuning with the SAFC.

 

[ECLIPSE4x4]

Like was said above, set it for the stock FP. No need to up the FP unlike like Andy said, if you injectors are maxed out.

 

[New2tuning]

Ok I think I got it. I need an AFPR because the 255 will pretty much flood my injectors so I use the AFPR to bottle neck the fuel pressure back down to stock setting?

 

[oldman]

Ok I think I got it. I need an AFPR because the 255 will pretty much flood my injectors so I use the AFPR to bottle neck the fuel pressure back down to stock setting?

You're not really flooding the injectors, higher pressure means higher flow rate, most of the flow rate rating you see are flow tested at 43 psi. You also don't want to bottle neck the afpr, you want to open up the bottle neck resulting in lower pressure.

 

[ECLIPSE4x4]

You will need and AFPR because you will over run the sotck FPR. You will not be able to return fuel fast anough.