AFPR, do I really need one?

[GSTwkd]

I've searched and read many posts and I'm still not sure if I really need an AFPR. My mods on my 95 gst are; hrc super16g, hrc smic, greddy i/c piping w/ bov, injen intake, 2.5" turbo-back exh. w/ hiflo cat, ported exh. mani, walbro 255lph fp, 550's, and safc with no internal or head work. It's my understanding that our stock fuel pressure has a base setting of 42psi and while you accelerate it should raise 1psi to every 1# of boost(20#s of boost = 62psi of fuel pressure?). At what point does the stock fpr stop working effectively? Thought I heard around 55psi. Right now I have my safc set at -32 across the board just to get my o2's around .94-96 and my egt's at 850-870c. Even with those settings I'm still running rich. I don't have any idle problems or driveability problems. So do I need one? If it will help with tuning and put less stress on my car then I'll get it. Also, after I install it will I have to re-set my safc setting. Thanks for any info as I'm still learning as much as I can about tuning.

I was waiting for Spoolin to come out with their 2g AFPR for the past 10 months but I'll just get a 1g fuel rail and get the 1g AFPR if I decide to get one.

 

[rdrkt]

every post I have ever read about the fprs has said that if you have a walbro 255 in a 2g you will NEED it. I am sure you are experiencing driveability problems with out really knowing it. I think it would be a wise purchase.

 

[kilurv8]

I got my 1G AFPR and 1G rail put on this weekend and I test drove the car afterwards and noticed a HUGE DIFFERENCE. I run a supra pump, so I am running even more over a walboro but the car idled much much better after startup, didn't want to die or anything. I need to pull the power from my ECU to reset the fuel mapping and what not so it can relearn things with this fuel pump, but it did make a huge difference. It does kinda suck though because I have to reprogram all of my tuning with the new fuel pressure but hey, at least it will be right this time.

 

[GSTwkd]

rdrkt-"every post I have ever read about the fprs has said that if you have a walbro 255 in a 2g you will NEED it."
pretty much same here on that quote, but was that with the HP255 or just the standard 255? I believe I have the stantard 255.

kilurv8-what was your base fp set at? Also, was I correct about the pressure raising with the boost? thanks again.

 

[kilurv8]

I dont know what my base was at before the adjustable FPR because I did not have a guage on there. It has been noted that a supra pump will push the base fuel pressure to 60psi. I have an upgraded line, so my pressure was lower but I had more volume so I was really rich. Just to let you know, I was at Charged Air Systems on sunday and we test fit the prototype regulator on my car for a 2G. It cleared everything just fine so they are supposed to be produced starting today but no promises. I had to get the regulator on my car becuase I have a lot of tuning to do prior to the SO.

 

[L2RTSiAWD]

I also have a 1G spoolinup on a 1G rail and my car has never performed and idled better. Yes I had to retune the whole AFC but that's half the fun.


Later,

 

[larryd]

fun huh, you call that fun

 

[L2RTSiAWD]

Originally posted by larryd
fun huh, you call that fun

Yes after I get it right

Later,