550s and Lex AFM....w/o AFPR???

[2543arvin]

Well, like the title says....Im running a Lex AFM with the RC 550s and I currently do not have the AFPR. I was wondering if it was still safe to turn up the boost. I was thinking of running around 15 psi. Will that amount of boost run the fuel rail dry with stock fuel pressure? I know that 15 psi isnt recommended on a rebuilt ct26 but if it blows then it blows....Ill upgrade! But I dont want to run my car lean especially after I just got the motor built. Anyone have any ideas or input?

Thanks

 

[mkIIIman089]

Without a wideband nothing is safe.

 

[2543arvin]

Without a wideband nothing is safe.

Yes, I would agree. Im just curious if any other members have done this and maybe had a wideband to know.

 

[Mr. Y]

I was running 550 + Lex without AFPR last year on T3/T4 bolt-on. It was pig rich under boost (10.8:1 iirc) and I have fuel cut around 20psi.

PS: but I dont think rising boost w/o WBO2 is good idea... too many things can lead to disaster.

 

[rumptis]

Well, like the title says....Im running a Lex AFM with the RC 550s and I currently do not have the AFPR. I was wondering if it was still safe to turn up the boost. I was thinking of running around 15 psi. Will that amount of boost run the fuel rail dry with stock fuel pressure? I know that 15 psi isnt recommended on a rebuilt ct26 but if it blows then it blows....Ill upgrade! But I dont want to run my car lean especially after I just got the motor built. Anyone have any ideas or input?

Thanks

If you have the money for a turbo upgrade, then get a wideband so you don't have to rebuild your engine.

 

[TurboWarrior]

I have the lex and 550s running at 16psi. I had it on a dyno and it was running rich.

My j-tube is bypassed and i have a walbro fuel pump. I suggest you do these things before trying.

 

[MKIIINA]

ran an sp61gt with a lex and 550s only for over a year without the afpr or pump @ 18-20 psi without issue. hella rich (i have a dyno graph around here somewhere.. was under 10.0:1)

i now have the setup you see in the sig

 

[MKTURBO3]

could you run lexafm and 550s without turning up boost no afpr no walbro 255 safe ?

 

[jetjock]

^ Sure, why not?

 

[TurboWarrior]

Doing those upgrades just raises fuel cut. If you aren't turning up the boost there is no point.

 

[CarlosPTR210]

I'm running a Lex AFM + Walbro 12V mod + RC 550cc + FPR with vaccum at 29psi + T4 A/R .70 = 10.0 A/F, I need to adjust the Apexi II :naughty:

 

[huntin5L]

Im on the same path with the 550s, lexus, walbro, fpr, and eliminating the jtube. Where on the site can i find information regarding these upgrades? Ive searched everywhere and i would of thought somebody would of done a writeup, maybe i just can't find it.

 

[supradoc]

so if ur running the 550's with the lex afm and get it tuned...it's ok to run without the AFPR?

 

[dok33]

The AFPR is mainly to lower your base fuel pressure for the bigger injectors so you don't run super rich. Without dropping the pressure you'll run pretty rich and it may not idle very well. Do you have a SAFC or other tuning device (didn't see any mention above)?

 

[TurboWarrior]

Im on the same path with the 550s, lexus, walbro, fpr, and eliminating the jtube. Where on the site can i find information regarding these upgrades? Ive searched everywhere and i would of thought somebody would of done a writeup, maybe i just can't find it.

There are a few ways you can do it. One way is to take the J-tube off and use a steel plate shaped the same to block it off with a new gasket, just leave the j-tube there disconnected, or drill out the restrictive part of the j-tube and keep using it.

After that all you need to do is just run the return line directly from the fpr outlet to the main return line instead. Of just keep using the stock lines if you decide to drill it out.

 

[2543arvin]

Thanks for the input guys. From what I understand the AFPR is used to keep the car from running rich from the 550 injectors. Ive got my car running 14psi right now, and Im content. Here soon, I will be getting a piggyback of some sort, so I can monitor and tune accordingly.

 

[supradoc]

The AFPR is mainly to lower your base fuel pressure for the bigger injectors so you don't run super rich. Without dropping the pressure you'll run pretty rich and it may not idle very well. Do you have a SAFC or other tuning device (didn't see any mention above)?

I've got an safc neo to tune it...so i'm hoping that'll be enough.

 

[TurboWarrior]

It will be enough. But the rough idle will be there with the fuel pressure stock. I find it annoying.