Translate GM/Ford/Chrysler injector Characteristics to Link G4X

[240makeyouhorny]

So I was afraid of this, but I bought some “cheap” injectors and the data they supplied I’m unsure if I can even use. I bought Snake Eater Performance GB SEP/ Bosch 1000cc injectors. Don’t ask my why I didn’t just spend the extra money and just get ID1050 or FIC since they’re reputable and proven, I’m not the brightest sometimes. I’m running them on a 1JZ VVTI with JZX100 PNP. The info they sent is dead times at 58psi fuel pressure, then a bunch of GM data which has some short pulse info, and then Ford and Chrysler info. I was planning on running 43psi(3bar) fuel pressure since my fuel system may not be able to handle the extra base pressure (for now) but they didn’t include info for 3bar. I’m honestly not sure what to input into my Link to even have the data somewhat correct, like min effective PW, deadtimes, and short pulse adder. I mean even what to input for injector flow @ rated pressure I’m unsure of with this data. I was planning on running modeled fuel so this is definitely becoming an issue. Also it could be my lack of knowledge and experience being completely confused by this, but I’d rather someone correct me than me damage my engine. Haha. 
 

I’ll include the flow data and spreadsheet “plug and play” data they sent me so maybe someone can help me translate it, or tell me I’m dumb and should just go buy good injectors.

Thank you guys! 

 GB1000_SEP21 Data.xlsx

[Adamw]

Flowrate - The LS7 ecu flow table uses differential fuel pressure Vs flow in g/s.  So from this table we can see @304kpa differential we have a quoted flowrate of 15.308g/s. To convert to cc/min we multiply by 60 then divide by the density of gasoline (say 0.745g/cc).  304kpa Flow rate for link = 1233cc/min.

 

Short PW adder you can enter directly from here.  It doesnt say what pressure that was derived at but I guess they use the default returnless 400kpa.  

 

For deadtimes use the LS7 table.  You can either just use the 304kpa column or if you have a fuel pressure sensor you could set it up 3D and use say one column each side as well.

[240makeyouhorny]

Thank you! You’re a life saver. I was looking at that info and thought I could possibly use it, but I just wasn’t completely sure if it worked that way. Especially the converting g/s to cc/min, I wasn’t sure how to do that. Thank you! 

[240makeyouhorny]

@Adamw I see that the Ford data has .1009 for minimum pulse width, and I believe the Chrysler does as well. I assume this would be minimum effective pulse width, but does that value seem low to you? I know from other threads I’ve read, I’ve seen that usually values are closer to like 0.8-1.2. 

[Adamw]

It is effective and that is about right.  Generally around 0.2ms is common

 

[240makeyouhorny]

@Adamw Sorry for bugging you again! So I got it up and running and was just playing around trying to get it to idle decent for now. I do not have an idle stepper installed anymore, but I got it to idle somewhat smooth at around 1000rpm. The only thing is the VE numbers in my fuel table to get 1.0 Lambda were around 85. Does this seem too high to you? I attached my tune file for my setup and hopefully a log of it running (unsure if I set the logging up right) if you’re not too busy if you wouldn’t mind taking a look and seeing if things look correct to you. Thank you! 

1jzvvti SEP Injectors.pclx PC Datalog - 2021-12-19 5_05_54 pm.llgx

[Adamw]

Yeah 85% VE at idle is not correct, it suggests there is less fuel being injected than what the ecu is calculating should be.  It could potentially just be poor control at the short idle pulse widths, or it could be poor data.  You could try tuning a bit further to see if the VE numbers become more realistic at higher loads which would indicate it is deadtime or short PW error.  If VE remains excessively high at higher loads then that would indicate the flowrate is less than quoted.