rc 550cc injectors

[strbo32098]

I just installed 550cc injectors along with the lex afm but I am still running stock fuel pump and stock fuel pressure regulator. I have a SAFCII and an adjustable screw on the lex afm. I just want to know how much you think I should be boosting? I have 3 inch down pipe along with 3 inch cat back and test test pipe and k&n filter.

 

[MDCmotorsports]

Untill you get some fuel to that setup, I wouldn't go over 14-15psi.

 

[chandley]

definitely wouldnt go over 15, probably safer to go with 12. However, even at stock boost, you run the risk of running your fuel rails dry with a stock fuel pump. just my .02

 

[MDCmotorsports]

^Yes'sireeeee.

Also if you are on stock HG and stock headbolts I wouldn't go over 10psi.

 

[tonysupra]

is it safe to just upgrade the fuel pump and not the fpr? would that cause any problems at all?

 

[Clifton]

is it safe to just upgrade the fuel pump and not the fpr? would that cause any problems at all?

You don't need a AFPR. You have the safc to control fuel. I would look into getting a wideband along with that fuel pump.

 

[87CandyBlueT]

You don't need a AFPR. You have the safc to control fuel. I would look into getting a wideband along with that fuel pump.

Nice 240z 7m Power!!!!


Also agreed with the wideband setup along with fuel pump. Also if you haven't recently changed the HG or performed a compression check i would insist on doing a compression check before running any higher boost than 7-8ish

 

[Kyle87T]

You don't need a AFPR. You have the safc to control fuel. I would look into getting a wideband along with that fuel pump.

Does the SAFC regulate fuel pressure? Even so, there are tons of restrictions in the stock lines.

 

[C.44]

Hmm i'm wondering, would it be safe to just put in the lexafm/rc550 combo with a bigger turbo(SP61GT) and have it @15psi ? If notis adding a Walbro 255 going to change that ?

 

[shaeff]

^ there's no way a stock fuel pump will supply enough flow for the SP61.

You don't need a AFPR. You have the safc to control fuel. I would look into getting a wideband along with that fuel pump.

eh, i like my AFPR. today on the dyno, i lowered the fuel pressure roughly 8psi in total, and from my first run of 275rwhp, i went up for the second run, then for the last, i got a best of 289rwhp/ 295ft lbs torque.

they were monitoring my AFR's, and i wouldn't have lowered the fuel pressure without doing so, but it IS a useful tool, in my opinion.

(that's a gain of 14rwhp just from messing with fuel pressure)

don't get me wrong, the SAFC/maftpro, etc.. devices are MUCH better for tuning, but having adjustability over the fuel pressure isn't a BAD thing.

-shaeff

 

[87CandyBlueT]

^ there's no way a stock fuel pump will supply enough flow for the SP61.



eh, i like my AFPR. today on the dyno, i lowered the fuel pressure roughly 8psi in total, and from my first run of 275rwhp, i went up for the second run, then for the last, i got a best of 289rwhp/ 295ft lbs torque.

they were monitoring my AFR's, and i wouldn't have lowered the fuel pressure without doing so, but it IS a useful tool, in my opinion.

(that's a gain of 14rwhp just from messing with fuel pressure)

don't get me wrong, the SAFC/maftpro, etc.. devices are MUCH better for tuning, but having adjustability over the fuel pressure isn't a BAD thing.

-shaeff

Which AFPR do you have? Did it come with a kit for the 7m? I have been considering getting one with my other fuel system upgrades.

 

[shaeff]

i've got an aeromotive AFPR. it was a steal of a deal kit. i assembled it all though. it didn't come ready to bolt on. i had to put all the fittings together and whatnot.

-shaeff

 

[strbo32098]

you said that you can adjust fuel on the safcII. What category is under? I am guessing it will be under settings and than the choices it gives me are low throttle, hi throttle and etc.

 

[C.44]

Would upping the fuelpump to a walbro 255(?) help solve that issue or would i need other stuff to run safe as a DD too ?

 

[thevork]

CandyBlue,

Someone at ebay is selling complete aeromotive kits.
The kits comes with everything from the gauge to lines and fittings.

I bought it a few months back and use it on my 550cc/lex afm combination.

Also, from what I have been experiencing, I think the best way to do your fuel setup correctly is setting it with the afpr. that way you can set your idle to be somewhere around a/f 15.

At that point you will be running richer at WOT (wich is good actually), and you can then use the safc to finetune it at high throttle.

Just my opinion and 2 eurocents

 

[87CandyBlueT]

CandyBlue,

Someone at ebay is selling complete aeromotive kits.
The kits comes with everything from the gauge to lines and fittings.

I bought it a few months back and use it on my 550cc/lex afm combination.

Also, from what I have been experiencing, I think the best way to do your fuel setup correctly is setting it with the afpr. that way you can set your idle to be somewhere around a/f 15.

At that point you will be running richer at WOT (wich is good actually), and you can then use the safc to finetune it at high throttle.

Just my opinion and 2 eurocents

Thanks a lot, I do not have a SAFC-II but it's on my shopping list. Thanks for the info. I'm getting an aeromotive kit.

 

[Yblegal91t]

im going to be selling the aeromotive kit w/guage etc very soon. just upgraded to maft-pro.

 

[C.44]

Would upping the fuelpump to a walbro 255(?) help solve that issue or would i need other stuff to run safe as a DD too ?

Any opinions in this matter ?

 

[thevork]

To be really safe you should always replace your 16 year old fuel pump by a new one when you are asking more from it than the factory specs.

Actually,
The 550cc/lex upgrade should always be done in combination with a new (upgraded) fuel pump and an AFPR and/or other fuel management system.

 

[Disced]

You all seem to be under the impression the stock pump can't flow?

Just to put my .02 cents in.

I run RC550's/Lex for approx. 1 1/2 years with no problems, not even problems @ idle with between 16-18 psi on the stock fuel pump and stock afpr.

When I dynoed @ 278HP and 337 TQ @ 16 lbs my A/F ratio was less than 10:1

You tell me if the stock pump can handle it?