hxtasy

IF I went temporarliy FMU set up, should i get larger injectors too? eventually I will get a VAFC or like.

also with the VAFC setup, I dont have to use the fmu then, correct? I have heard of people using an FMU and a controller, and some with just the VAFC. I dont understand this I thought the controller controlled fuel through the injectors, then why do you still need the FMU???

thanks.

primeredbeast

fmu doesn't need injectors if you are running real low boost remember injectors are a band aid setup imo

hondaeg8

i ran a 12:1 fmu with stock injectors and then 310cc injectors on my stock ls motor pushing 10psi... no problems

hxtasy

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hondaeg8 &raquo;</TD></TR><TR><TD CLASS="quote">i ran a 12:1 fmu with stock injectors and then 310cc injectors on my stock ls motor pushing 10psi... no problems</TD></TR></TABLE>

so when i have the money for a VAFC, does the FMU go, or can i still use it? what will it do if i keep it? thanks.

BoostR41

you can still use the FMU but you will need more boost to compinsate. I ran 450cc injectors, afc, 255lph pump, missing link, and FMU for 2.5 years with no issues.

if you have a stock b series vtec motor I would get the inline pro head gasket. on my stock block with that head gasket I ran 17psi on C16 and 14psi daily with the above set up.

b16ahybrid

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostR41 &raquo;</TD></TR><TR><TD CLASS="quote">you can still use the FMU but you will need more boost to compinsate. .</TD></TR></TABLE>

That makes no sense to me. Could you please elaborate on your reasoning.


To answer your question, if your running small injectors (310cc or so) you can still run a fmu and afc. My old fuel set-up consisted of the following.
4:1 fmu, 310cc injectors and a sfc to fine tune the a/f ratio.
If you want to run the hack then you don't need a fmu. There are several different variations to this kind of set-up, try searching through the archives and your bound to find a few different variations.

BoostR41

ok what you do is you get a cartech FMU so it is adjustable like a FPR. using the FMU you can dial back injectors on the AFC but I kept it so I didn't mess too much with the afc because of the timing issues you can have with it. my ratio on the FMU was right around 10:1. with it at 10:1 you are maxing the pump out so you get to a set presure. after that boost leans the mixture because you are gettin more air and the same amount of fuel. My af ratio never went leaner than 11.2:1 on that set up.

it is crude and hondata is the way to go but if you use it right it works very well.

b16ahybrid

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostR41 &raquo;</TD></TR><TR><TD CLASS="quote">ok what you do is you get a cartech FMU so it is adjustable like a FPR. using the FMU you can dial back injectors on the AFC but I kept it so I didn't mess too much with the afc because of the timing issues you can have with it. my ratio on the FMU was right around 10:1. with it at 10:1 you are maxing the pump out so you get to a set presure. after that boost leans the mixture because you are gettin more air and the same amount of fuel. My af ratio never went leaner than 11.2:1 on that set up.

it is crude and hondata is the way to go but if you use it right it works very well.</TD></TR></TABLE>

Maybe it's the way you word things or maybe it's something else, but your posts are very confusing.
Use a fmu to "dial back injectors on the afc" ??? Your talking about two totally different items here.
I think I understand what your trying to say, but it comes out and mixed together into one thought.
Are you trying to say that you run a fmu with a 10:1 ratio, then use the afc to lean the afr out if you need to?
Either way you are correct about it being a crude way of tuning.
I thought you were trying to say that you up to boost until your top-end is close to ideal a/f ratio. So for instance if your running 310cc injectors 12:1 fmu and 8psi your obviously going to be running pig rich. So instead of changing the fmu ratio you raise the boost to say 12psi so the top-end isn't so rich.

K.I.S.S stick to it and it makes life easier.

SOHC_MShue

My friend had a similar setup running a fmu,255lph fuel pump, 440cc injectors, and an afc. To tell you the truth it ran like ****. We had the afc set to -50% across the board and it was still insanely rich at part throttle boost and before full boost hit. Its probably because he had to high of a ratio fmu though. Once we switched to uberdata and ditched all that crap the car ran great