VEMS and Ford light green injectors roughly at idle

[A80Avant]

im sorry, but i dont think this is right.
req_fuel is the calculation of injectors @ their specification, NOT the fpr used.At least that is what VEMS and efiexpress have on their websites.

besides as i have been told, injectors 440cc @ 3bar are not calculated with a simple equation to find their flow @ 4bar or 3.8bar because it is not analogous.

So 6.49*(2226/5/440)=6.5 OR 4.9 (if you want 75%).

thats what i use at least and got the 6 instead.

of course, i could be wrong which is why im getting DC over 100% on the log viewer, but hey,that is what i was told.
if the fpr bar needs to come into play, then we need the excact equation, or a flow meter to see what it flows at the fpr bars to put it in the equation

[Jamo]

im sorry, but i dont think this is right.
req_fuel is the calculation of injectors @ their specification, NOT the fpr used.At least that is what VEMS and efiexpress have on their websites.

besides as i have been told, injectors 440cc @ 3bar are not calculated with a simple equation to find their flow @ 4bar or 3.8bar because it is not analogous.

So 6.49*(2226/5/440)=6.5 OR 4.9 (if you want 75%).

thats what i use at least and got the 6 instead.

of course, i could be wrong which is why im getting DC over 100% on the log viewer, but hey,that is what i was told.
if the fpr bar needs to come into play, then we need the excact equation, or a flow meter to see what it flows at the fpr bars to put it in the equation

Really, well we'll see when you get to the higher firmwares which really heavily on the req_fuel for starting.

The flow was calculated using the RC calculator who make injectors, I think they know a thing or two http://www.rceng.com/technical.aspx

The req_fuel is the injector open time to make stoich if your injectors are rated at 3 bar but your fuel pressure is 4 bar you injectors have to open for less time as they will flow more for that give point in time, so yes you must adjust the req_fuel to suit.

[A80Avant]

if that is the case, why isnt it mentioned anywhere in VEMS or elsewhere about the fpr used?

dont worry as to how i will do on higher firmwares. And believe me, req_fuel is not the only thing you need to have nice running. Billman has been running 630cc injectors as well as others with no issues, + with wrong ramp up times as well. I have no problems with idle, or any other map bin on that matter as well. Good for you, you found what your RC injectors flow.Although you are changing them now. If it was that simple to get everything perfect with req_fuel, everybody would have perfect results.

it does sound more logical to put the flow rate at its fpr, i agree, but if the equation is set in the hardware with the advertised spec of the injectors,i believe it is something that VEMS hardware figures out on its own to make the proper mixtures. As i said, it is not as simple to say 440@3bar = 508@4bar because it is not.

[GazzaG60]

there are benifits to a high or low req_fuel.

the ve table is where we compensate and to and extent accel enrichment.

i calculated wrong on mine. i used the rating at 3bar. it runs fine. mine req is like 4.8 and i think it should be down near the 3 mark.

i dont get too hung up on req fuel. linkecu for instance uses numbers 1-5 IIRC in early versions so not much variation. lots of time mapping brings in inline.

[Jamo]

It is mentioned on the wiki by Marcel

s2central or sjmautotechnik talks about differences between AAN and 3B. (TODO: find the link).

* fuel pressure
o AAN FP=4bar
o 3B FP=3.5bar

That means sqrt(4/3.5) = 1.07, so 3B injectors flow 7 percent less, therefore require req_fuel of 7% more. (also roughly 7% more cranking pulsewidth).

[A80Avant]

so it is all not too mathematical then. Im with Gary on this one. Req_fuel is not hugely important,unless it is so wrong that you end up not having numbers to put in the bins >255 or something.

on the 630cc injectors i plan to use the correct ramp up for the siemens and get the req_fuel values as convinient as possible as i plan to redo the VE table from scratch, rather than just my existing one.

[GazzaG60]

i just popped the 630's in exchanging them for the standards. set req_fuel and it run sweet. im not **** on the ramp-up for sure. if its works no need to fix.

my view is this.

req_fuel is important as the constant applied to the injectors. the formula applied to get the fuel out uses ve and req_fuel. therefore changes to ve will compensate for the wrong req_fuel.

on other ecu's there is a target figure for say middle of the map. on LINK systems thats 60. im not aware of a figure on vems.

[A80Avant]

the ramp up on the dekas is 280. i have mine set by mark on 192.I will have it changed anyway in the process of the new mapping. Maybe it will fix the over 100% DC as well

[GazzaG60]

doubt it. either its calculated or actual.

if actual then the injector is full duty and will explian the dip to super rich. i had this at 4k on the standard injectors at 1.2 bar or so. it would dive to 10:1.
if calculated a lower reQ-fuel will change this. if like me you set the injectors at 3 bar then the 100% is not so accurate.

[Jamo]

Depends on the injectors Gazza, mine work better with 0 ramp up and the injector open time value as supplied by RC

[GazzaG60]

not doubting they will work better with the correct settings just doubt it will make a difference to DC.

like i say mine work well with the same settings i had before. from aby to dekka

[Rocco]

talking about injectors and diferent powers....

how many HP power more or less can be used with the 7A 4´2bar FPR + RS2 fuel pump relayed to 14volts and original RS2 injectors (360cc/3bar true?)


thanks masters

[GazzaG60]

around 400hp id expect.

id just fit an 044 and some dekka 630cc to avoid going over 80% DC

[A80Avant]

i know that the easy way to do it is to just keep the VE map and dial the req until i get my 1.00 lambda on the same VE value on idle, but hey.I like a challenge! Besides, bigger turbo will need new mapping anyway, so i may as well do it right.

if the DC changes or not, not really bothered since i can still hit 0.70 lamda and not have any enleanment. Im sure something is not read right, otherwise if my injectors where reaching their limit, then i should be going lean,which im not.

[GazzaG60]

its nice to redo things somtimes.

i am 12x12 and just written for the bigger scope. will get it insoon.

i see massive differences in power between 0.7 ans 0.77 or so.