Can anyone decode this Greek? (Injector Data)

[samh_08]

I am working on the black magic injector tables in my tune. I started out with stock 26.6lb/hr truck injectors (05 Chevy 6.0L.) After Heads/Cam/Headers I figured it would be wise to get some bigger injectors.

I bought the new shorty LS2 injectors which are flowmatched at 42lb/hr @ 4 bar (58psi). At first I copied as many tables I could from a LS2 tune to my tune. I dont like to assume that both PCMs run the same way especially when there is two different LS2 tunes (at least injector data.)

Long story short, I called John from FIC (Fuel Injector Connection) and got all the raw data I could from the injectors I bought from him. He faxed over what he had, and I found out that most of it was written in Greek.

Attached to this post is what he sent me via fax. I want to get the proper data from that data and somehow put it in my tune. I am running a GenIII PCM. If I looked at it long enough Im sure I could figure it out, but I'll ask here first .

Let me know your thoughts,
Sam

[Aloicious]

I am working on the black magic injector tables in my tune. I started out with stock 26.6lb/hr truck injectors (05 Chevy 6.0L.) After Heads/Cam/Headers I figured it would be wise to get some bigger injectors.

I bought the new shorty LS2 injectors which are flowmatched at 42lb/hr @ 4 bar (58psi). At first I copied as many tables I could from a LS2 tune to my tune. I dont like to assume that both PCMs run the same way especially when there is two different LS2 tunes (at least injector data.)

Long story short, I called John from FIC (Fuel Injector Connection) and got all the raw data I could from the injectors I bought from him. He faxed over what he had, and I found out that most of it was written in Greek.

Attached to this post is what he sent me via fax. I want to get the proper data from that data and somehow put it in my tune. I am running a GenIII PCM. If I looked at it long enough Im sure I could figure it out, but I'll ask here first .

Let me know your thoughts,
Sam

That, my friend, is a stock Ford injector datasheet. in fact, it looks like this exact one: http://www.fordracingparts.com/parts...-9593-mu32.pdf
taken from here:
http://www.fordracingparts.com/parts...KeyField=10512

the problem with that, is the way Ford calculates the offsets and small pulse tables is quite a bit different than what GM does. IIRC, Ford combines the small pusle table and the injector offsets into a sort of 'total offset' type of table, so using the exact data from that chart in GM tunes will NOT give the accurate and correct results. and unfortunately you're no closer to the correct info than you were before. not even the IFR data is directly applicable because Ford tests their injectors at 39.15psi of fuel pressure, so conversions there are necissary as well to be more correct for your specific setup. in fact even the MINPW data (minimum pulse width) on that sheet is in relation to a fuel system PSI of 39.15, so I don't know what effect a standard 4 bar (58 psi) GM fuel system would have on alot of these variables.

unfortunately, the correct data is pretty hard to come by in most cases. there is only 1 company that I have seen which can actually test for these variables, but the testing is pretty expensive. it's Paul with YAW power. he has some good reading on his site about injector dynamics if you look it up.

Other than that, you could either get some stock GM injectors and copy the injector data from a tune which uses those injectors in a stock application.

I've heard good things about Jon and FIC's work, and I am not trying to contradict that. however I have a problem with this stock Ford info being given out for GM applications without explaination or how to extrapolate useful data, you're not the first person I've seen that FIC has sent the ford tables to for a non-compatable GM application.

[5.7ute]

I agree. I spent a few minutes converting the data over to our units & I dont believe there is enough info to extrapolate to our tables. None of the offsets are linear, as has been shown in the past. So the only data we can use is at the 60lb delta pressure on those sheets. I will keep playing with this data though & see if I can come up with anything.

[samh_08]

Just what I wanted to hear...

How can they be Ford if they are used on LS2's? I thought I finally was going to get a break. If anyone at all can help me, please do! Take it as a challenge .

Thank you for the info so far, hopefully we can get something figured out.

Sam

[Aloicious]

Just what I wanted to hear...

How can they be Ford if they are used on LS2's? I thought I finally was going to get a break. If anyone at all can help me, please do! Take it as a challenge .

Thank you for the info so far, hopefully we can get something figured out.

Sam

well....he's either sending you the ford injectors and giving you the ford data for them, OR he's sending you the LS2 injectors, and just giving you the ford data from 'simmilar' injectors, (though the data isn't simmilar, and likely the injectors are somewhat different as well).

if you can verify that they actually ARE genuine LS2 injectors, I would take the data from an LS2 tune if you can.

to Jon's defense, he most likely isn't able to test the dymanic data like offsets, so he's just trying to provide simmilar info that he can find. and maybe he's not aware of the GM/Ford tuning differences. BUT, its just very misleading to the customer to give them incompatable ford data for an obvious GM application, and not inform them of that.

I'm working on designing a dynamic flow bech to test these odd injector dynamics, partially for fun (I find injectors fascinating), and partially for some of my engineering classes. once I get it finished I'd love to test some various injectors to help y'all out, but that is quite a ways away as I'm still designing the circuitry for it.

[samh_08]

Here is the response I received back from him. Most of our conversation was on the phone, but I PM'ed him tonight to get more answers.

Proceed ..

hi the injector is the same as ford uses. Also Bmw, rover etc. ford is the only OE that published injector data. All ev14's like ls2 are made by bosch, Yours are factory ls2, using the same coil and injector body in the fords. there is no such thing as a ford injector. Since you cant load a ls2 tune in your computer, this data is the closest you will get. Unless you can get a tune from a guy on efi live that has put one in. voltage offset, latency, deadtime is all the same thing. Did you fire up the engine yet? You might want to get to a dyno and do a live tune over a mathematical. Alot of guys start with the stock tune and change just the IFR vs voltage table, then fine tune the ve.. what did you do so far and whose tuning it?
jon

[joecar]

You should be ok with the LS2 tables...

Post the two LS2 files you're looking at.

[samh_08]

You got it Joe! I could also look up what exact year and model GM used this injector..Anyone have that kind of resource available to them? Seems like a better way of tracking down my true numbers.

Tune file 1 = 05 Corvette LS2 6.0L
Tune file 2 = 06 GTO LS2 6.0L
Tune file 3 = My current hacked tune

Notice that the LS2 has different injector tables than me. This makes me wonder if Im only getting half the picture...

[Aloicious]

Here is the response I received back from him. Most of our conversation was on the phone, but I PM'ed him tonight to get more answers.

Proceed ..

he's correct, its not a 'ford' injector, its made by bosch, but it is made to ford's specs, and there are differences between different EV14's even within different manufactuing runs you will get variances in injector charactoristics, but these are typically small enough not to worry about, but go look at a bunch of different tunes using the same injectors, you'll see different small pulse adders, different voltage offsets, etc.

thats not the complaint I have with what he's told you though. the issue I have with his info is that the ford PCM tables ARE NOT THE SAME as GM's so just putting the ford data (from his fax) in WILL NOT be correct, he says that the faxed data is the most correct for the injectors, he is probably correct, in a ford tune, not a GM one. they calculate and use these tables differently. Greg Banish (eficalibrator here on the forums) is a good guy to talk to about the differences between the the ford and GM tables, he used to be a ford OEM calibrator. its nice that Jon is going to the trouble to at least provide some info, I just wish he'd tell people, that the info he's giving is from the ford OEM tables and may not work in other applications. you're the second person I've talked to who's tried using this info in a GM tune and didn't know that the ford and GM tables aren't directly compatable with each other.

just do like Joe mentioned and pull the data from a simmilar LS2 tune. you should be good. I'm at work so I can't check out your tunes here.

[scdyne]

I had the same general questions last month and here is what Greg Replied to me in a PM.

Be careful directly comparing the Ford calibration summary to units that would be plugged into a GM ECU. Not only are the working pressures different, but the point in time represented by the Ford offset and GM offset are different. In order to solve for the GM offset and short pulse adjust I had to first interpolate to 58psi using Ford units then back-solve to GM units from the raw mass vs time curves at the reference voltage.

...all that said, the minimum pulsewidth is really just the shortest controllable opening and closing event at whatever pressure you're using. This is either found by testing a few thousand injectors and statistically analyzing the behavior or by just taking a SWAG based on empirical behavior on a real engine or three. The numbers in the DVD's disc are based on the latter experience and should allow for a clean idle at stoichiometry on most engines.

I did math out everything including the minimum pulse width (my specific question to greg) in the last few weeks and once I get the GM EFI Tuning DVD, I'll know weather I was correct or not. I can hope, but I know working in Instrumentation Testing for a living that chances are I'll be wrong.