I was just curious, How do you know when you are pushing the limits of your fuel pump?
I know i am using alot more fuel than stock, but so far i have never experienced a lean condition or anything, and am hoping to avoid that... So how do you know when you need what mods before you go lean?
I am slowly bumping the boost up, and trying to make the needed mods as i go.... (hopefully do the mods before they are "needed")
I am curently at 12psi, on stock fuel pump and GM SC injectors... These are holding up fine so far, but i am about to push her over the 2 bar line, and just fear i will quickly be pushing these fuel components too far. I have a set of 440cc RC injectors i can drop in. I have just been trying to get my VE's in range before i go swapping injectors. Does anyone know what a good starting point is for 440cc injector constant? I have seen a few different people running different constants and all seem to be quite happy. So just looking for some insight before i dive in.
What is the reason that so few people run "inline" fuel pumps? is it just noise? or are they unreliable? or what?
Is the blazer pump a perfect replacement? i thought i read that the blazer pump has some of the same issues as the 255 with the 1/4 tank starvation....
I just hoped there was an "ideal" solution to add more fuel flow.
Your running 12psi on ld9 or lsj sc injectors??? Either way, they are way to small for that amount and more. Whats your IDC using those? Your probably pushing those injectors way too far
And look into the racetronix pump. People seem to love it.
Yeah I do not see how the GM 310cc injectors are not over 100% IDC at 12 psi.
FU Tuning
what pulley set up do you have?
My LSJ injectors held up to a over drive crank pulley, and a 2.6 charger pulley.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
i have a 2.7" pulley on the SC, and just put my half bar spring in the Wastegate this AM.
just took a lil drive this am and was able to peak to around 15psi... AFR's still in the normal range. no lean spots that i could see.
I am a lil surprized myself... which is exactly why i made this post. I figured i would have maxed the SC injectors a long time ago.
I have the LD9, and the LD9 GMPP SC kit (mp45) and those are the injectors i am running... which i am pretty sure are only 310 or 320cc.
310..
you need to log it with HPT to get a real feel for it.
what kinda CFM is that turbo pushing?
310's should have maxed out some time ago. log it, see what intake air temps\KR is at.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
yeah your injectors are deff maxed out, i had to put in LSJ injectors when i upgraded the pulley to 2.6" and meth injection.
You do not seem to understand that the injectors being maxed out does not reaslly mean it will go lean. It means the IDC (injector Duty cycle) is 90% +. When you get to 100% IDC your injectors stay open all the time to try and keep up. Your 310cc injectors are past 100%.
FU Tuning
i have logs...
but my IDC is an "unsupported parameter"
i watch my AF and temps all the time...
just dont see anything jumping out at me saying im in need of more fuel.
to monitor injectors, log duty cycle. If its over 80% its time to get larger ones.
to monitor the fuel pump, log fuel pressure on the rail. If it fluctuates on wide open throttle (usually dropping with higher RPM) you're pump is too small.
go with the racetronix intank replacement. Best fuel pump for the Jbody IMO at the moment.
Yea I also maxed my 310's with a 2.6 charger pulley, and spraying nitrous on top of that was much worse lol. I can guarantee yours are being pushed way farther than they should be.
Id pick up atleast some 550cc's or larger. For your goals Id just get much larger low impedence injectors and use a reistor box.
I am trying to log injector duty cycle... but it keeps coming up as unsupported parameter once i connect my car.
tell me more about this resistor box.... I hear that low impedence injectors are alot cheaper, i just didnt think i could run them. I was hoping to sell my 440's and get something bigger before i "needed them"
cuz i figured 440 wasnt quite enough for where i would like to be in the end.
So please tell me how to config HPT to get the info i need.... and how to get the injectors i need at a good price.
let me know what i need to get IDC to work in hpt.... and how do i log fuel pressure? i didnt think our cars had a fuel pressure sensor. let alone the ability to log it.
what injectors do you all recommend... i want to keep good drivability... but also would like to handle my need for power... I would like to push this thing to mid 20 psi.
duty cycle is a non-supported parameter.
You have to set it up as a calculated parameter to get it to read. It is a calculation between injector pulse width and RPM. you need to log both of those in order to get a calculated duty cycle. you can set it up in the parameters of the scanner.
Once you do, look at your duty cycle, and see what kind of #'s it has. I am guessing you will be over 100%. And as PJ stated, you need to monitor fuel pressure under WOT to see if your pump is to small, and also agree with the racetronix replacement.
injector size is all based on HP, not boost pressure. If you know what HP you are making now, you should be able to scale off that with the added boost to get a rough idea where you will be at on your final boost plan. Then you can calculate the correct size of injectors.
as far as a resistor box is concerned, you just need to wire in a specific resistor in line with each injector. most low impedance injectors read 2-5 ohms, most high impedance are 11-15 ohm. you you would need to put a resistor inline to mimic the difference.
Anyone want to buy my RC 440's or split a set of 8 big guys with me?
I found a bunch of good big injectors... but they all seem to come in 8's i only need four.. so anyone want to split some with me?
maybe some 60lb or 83lb "seimens deka performance injectors"
How much do you want for the 440's? Might need them for the dd. Do they plug in to the stock harness?(00-02)
jmarks82 wrote:How much do you want for the 440's? Might need them for the dd. Do they plug in to the stock harness?(00-02)
RCE high impedence, Bosch style connector. 00-02 is a Multec 2 connector.
jmarks82 wrote:How much do you want for the 440's? Might need them for the dd. Do they plug in to the stock harness?(00-02)
If you used the harness that came with that motor, it has the older style connectors on them.....
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
John Higgins wrote:Let us know what your IDC is.
as soon as i get back to my car, i will gladly let ya know... right now i am about 800 miles away from it..
ok as far as recording injector duty cycle....
would [PID.6202]*[PID.12] / 1200 work?
6202 is inj 1 pulse width....
12 is rpm
i just replaced the sensors used by hpt with the PID's our cars use...
I cant see if it works yet.... but it sounds right to me?
anyone?
Are you guys serious?
The stock LSJ injectors work with that low of pulleys for you?
Jeeze, we have to go with 60#'ers for stuff that low, along with heat exchanger and meth injection etc etc.
Lucky lol .
.
Lols.
daythecountrydied21 ok wrote:Are you guys serious?
The stock LSJ injectors work with that low of pulleys for you?
Jeeze, we have to go with 60#'ers for stuff that low, along with heat exchanger and meth injection etc etc.
Lucky lol . .
you are running an m62....
K. Vega..Mr. M62 L61 himself. wrote:daythecountrydied21 ok wrote:Are you guys serious?
The stock LSJ injectors work with that low of pulleys for you?
Jeeze, we have to go with 60#'ers for stuff that low, along with heat exchanger and meth injection etc etc.
Lucky lol . .
you are running an m62....
uh...ok? i know that?
I'm saying, our 32#'ers or w/e they are stock are already maxed out stock.
42#'ers are okay if you're looking for not much more power than a stage 2 tune.
60#'ers are what you need if you're looking to make bigger power, coupled with a smaller pulley 2.7 or 2.8, any lower won't be much more beneficial...
I just saw people posting that 32#'ers would be sufficient and thought that mybe for some odd reason you guys could run on them........
Lols.
Stock m45 pulley is a 2.8", stock m62 is what like 3.3 or something?? So say a 2.6 pulley on a m62 would be much smaller than stock, whereas an m45 would only be 2 sizes smaller. The m62 is also a much larger sc, even with stock pulley they see more boost than most pullied m45's.
icemike89 wrote:Stock m45 pulley is a 2.8", stock m62 is what like 3.3 or something?? So say a 2.6 pulley on a m62 would be much smaller than stock, whereas an m45 would only be 2 sizes smaller. The m62 is also a much larger sc, even with stock pulley they see more boost than most pullied m45's.
Oh duh
.
Didn't realize that the OP was a Z.
My bad, i thought everyone was talking m62.
Would explain all the smaller pulleys with lower # fuel injectors lol.
Lols.
