440cc vs 550cc injectors

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i see grasshopper.

im sooo close to having all the shizz for my turbo setup but ive been stuck for a while now on the FMU or fuel press regulator. whats the damn difference between the 2? are all fuel pressure regulators 1:1 unless they say otherwise? is this one 1:1? and will it work with my setup with my inline FP? my head's literally been spinning for the last week about this :spin: helpkthxbye

PS-why do some people use a 12:1 FMU? im guessing thats if you dont use an inline FP?? fuck IT.. just shoot me now
 
FPR sets the BASE rail pressure.... usually in the low 40's psi. it is 1:1, as is the one you linked. that one is adjustable- meaning you can set base pressure say, 50 psi.

and FMU, RAISES in ADDITION to the FPR 12 psi of fuel pressure for each psi of boost it sees through its vacuum line (in a 12:1 fmu).

so if you are running 6 psi off a 12:1 fmu and the stock fpr-

you have 42 psi in the rail at idle/out of boost.
a 1 psi you have 54
at 2 psi you have 66
.
.
.

the key thing to remember, is that PRESSURE is NOT VOLUME. and that's why fmu's are only good up to say, 6-8 psi on a medium t3/t04e turbo, and 10 on a smaller t25

the fuel pump is mutually exclusive.
basically, if your rail is calling for 100+ psi, your stock pump simply can't deleiver it fast enough- and thats where the inline booster comes into play.
it raises PRESSURE once again, and again, is only good to a certain point.
the INTANK pumps, actually FLOW MORE VOLUME (litres per hour).

to sum up- here's what you need, one of the following:
  • 12:1 fmu, missing link/map bypass check valves, stock injectors (310s are know to work, but push it a little bit... so, stock 240cc-310cc is the range), inline pump booster
  • no fmu, no missing link, vafc, intank pump (preferred- but an inline MAY get you by), and 440 injectors in "hack" formation
  • no fmu, no missing link, no vafc, hondata/uberdata/aem/etc, larger injectors sized to application, intank pump
with either of those setups, the stock FPR is fine. I am running the stock one.
But, if you need a HAIR more fuel, a FPR can aid in giving you a slightly higher base pressure, and thus, overall more fuel throughout the rpm band.
but again, remember, PRESSURE IS NOT VOLUME.

so to sum up the differences-
FPR sets the base rail pressure.
FMU ADDS to the base rail pressure in ratio (12:1) for each pound of boost it sees.

to take that a step further, running high rail pressure, caused by the fmu, requires fuel to actually BE THERE in the first place. cuz you can't feed the motor what hasn't been brought up from the tank, through the filter, and into the rail- and that's where your inline booster and intank pumps come into play.

clear now?
 
Originally posted by pissedoffsol@Mar 29 2004, 02:10 PM
hondata is NOT that expensive. I would not recommend anyone to tune their car themselves if they don't know what they are doing.
I am paying someone else to tune mine, and a lot of you think i know a lot about turbos and tuning. fact is, i don't. At least not enough to the point where i feel confident in my knowledge of EFI. and i'm not willing to let my lack of knowledge blow up $10k in parts.


:werd: I mean absolutly NO disrespect here and am not trying to be mean or say that im better than you in any way, but if you have to ask these questions, I wouldn't attempt tunning a car, go chill around a dyno for awhile and watch someone blow up their car, the 200 bucks in tunning is NOTHING when i comes to the possible alternatives, its kinda like open heart surgery, sure you could try it yourself and save alot of $$, but wouldn't you feel better just leaving it up to the guys who know what their doing?
 
clear now?

crystal :D thx B

Originally posted by Bl6CRX@Apr 3 2004, 12:02 AM
I mean absolutly NO disrespect here

none implied :D

but if you have to ask these questions, I wouldn't attempt tunning a car
i guess that makes me look stupid cause i didnt know the diff between the 2 :p i know what a fpr is but became confused when someone tried to tell me to use an adjustable fpr and set it to 12:1, then i hear use a 12:1 FMU so thats why i was like WTF is the diff? it all comes down to who you ask, thats why i knew if i came here and talked to Brian, the clouds would part and the sun would once again shine :D if i cant figure out how to tune it myself with an IQ of 135 then i guess i still wasnt smart enough to know better :( i realise its a dangerous time-comsuming process but fuel maps and that stuff interests me..

thank you to all posts :)
 
tuning is a science and a skill. even the smartest people can't tune cars.

what makes a tuner is experirience- and thus, 1002323 blow motors. do't try it out on your brand new setup.
 
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