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Thread: Siemens 80# injectors, modded turbo Cruze... help calibrating?

  1. #1
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    Siemens 80# injectors, modded turbo Cruze... help calibrating?

    Hello. I bought some but I think I went too big. I have a LOT of airflow. Pretty much whatever you can get besides a bigger turbo, I have it installed. I bout them from zzp, and when I installed them, they were just SO rich, I couldn't get the car to idle. I have tried a lot of things, but I either cannot find something specific (or even close, mostly gen III stuff for muscle cars) or conflicting stuff. Yes, I have searched, I have read... a lot. I just want to hear some opinions from youse.

    These are the ones I bought:

    https://zzperformance.com/products/s...80-injectors-5

    But yeah. Any advice on where I would start, short of returning them and getting 60# injectors? I have had to turn down my tune because it wants to go, but I have not room, fuelwise at the injectors, and I know the fuel pump can flow enough for what I want. At least for now.

    Thanks

  2. #2
    I have massive injectors on my chevy spark. I added a cruze turbo and run e85. I think my injectors are like 80#. I can upload my file when I get home and you could use or reference my injector data for a base tune. Did you alread enter the injector vs flow rate data that came with the injectors?

  3. #3
    Just looked at the link, I'm 90% sure I have those exact injectors

  4. #4
    Senior Tuner cobaltssoverbooster's Avatar
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    i would try some e38 injector data from FIC and see how it comes out. at the worst if the tables are the same then you can always get a set from them and now you have the correct data to match a calibrated set.
    http://fuelinjectorclinic.com/hptuners0850
    2000 Ford Mustang - Top Sportsman

  5. #5
    11.1 tune 1.hpt Here is my tune. I think I only adjusted the flow rate vs pressure and minimum injector pulse

  6. #6
    Senior Tuner cobaltssoverbooster's Avatar
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    do you have a return regulator with boost reference or oem setup?
    2000 Ford Mustang - Top Sportsman

  7. #7
    Good point cobalt. For clarification, mine is oem.

  8. #8
    Senior Tuner cobaltssoverbooster's Avatar
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    here try stuff from this file.
    in the oem condition your high kpa delta pressure where you exceed the 127 lb/hr flow rate isnt really a huge deal because thats where decel is. if you run defco active then you shouldn't be way off the end of that table spraying fuel.
    each tab tells you the table it fits.
    these aren't for SD80's but it has a chance to get you close and possibly in a workable range.
    Attached Files Attached Files
    Last edited by cobaltssoverbooster; 11-12-2019 at 07:30 PM.
    2000 Ford Mustang - Top Sportsman

  9. #9
    sweet. Thanks for sharing Cobalt. Like OP, I did a lot of research and my file is just the result of what I was able to put together. It works but I'm excited to try this out. Thanks again!

  10. #10
    Senior Tuner cobaltssoverbooster's Avatar
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    so check this out.... in the past i have done some injector studying and found a old thread that has long since died but it works very well for tuning purposes where stuff happens to be unknown.

    i tend to monitor the fuel system under cruise situations. i tune everything for as close to steady state as possible and when i cant i make damn sure anything under deceleration is removed by using slope filters on rpm and/or tps.

    where the old dead thread comes into play:
    older stand-alone systems were crude and test benches were expensive and rare at the time. So how do you calibrate without getting crazy? its not a standalone like a MS3 so you cant command an injector at a predetermined pulse period, so how do i get dynamic flow data?

    1) set the injector offsets to a multiplier factor of 1.0. in the case of the E78 its not a multiplier; instead its an adder table so to make it equivalent to a factor of 1.0 multiple you just set the whole table to 0.
    2) put the suggested flow rates into the ecu flow rate box.
    3) record standard maf calibration data because this is how you tune the fastest in this test method
    4) record trim or afr error against the manifold flow rate table axis. in the E78 the axis is KPa delta so the math here is fuel rail kpa - manifold kpa. as the vacuum increases the delta gets larger, and vice-a-versa for boost(Boost+/delta-). For this histogram add a filter that removes data when injector pulse is bellow active short pulse adder ms value. The threshold works fine and is usually around 3-4 ms.
    5) tune your maf sensor data in until the error is low and consistent. from this log record the average error data on the fuel flow rate histogram from a ~30 min or longer drive.
    6) add 10% to the maf table so it runs rich. and record the same ~30 minute or longer drive the best you can.
    7) analyze- you need to find the difference between the 10%+ test and the tuned in base test. (base error - 10%+ error = error difference). What you are looking for is a a result that nets fairly close to 10% difference because that is how much you manually forced into the situation.

    7A) if your delta is smaller than 10% then the injectors are calibrated too large. the split between the target and delta is your correction %. i usually halve this value to reduce the effects of a single calibration change. when making the change to correct in this case, you should be multiplying by a value under 1.0.
    Example: If my delta is 8.2% and my target is 10%, then i have 10-6.2=3.8%change factor. reduced change factor is 3.8/2=1.9%. to figure out multiply value for editor take 1-0.019=.981. Multiply the IFR value in question by .981 to make this change.

    7B) if your delta is higher than 10% then the injectors are calibrated too small. do the same thing as 7A) but in reverse.
    Example: If my delta is 14.8% and my target is still 10%, then i have 14.8-10=4.8% change factor. reduced change factor is 4.8/2=2.4%. to figure out multiply value for editor take 1+0.024=1.024. Multiply the IFR value in question by 1.024 to make this change.

    when the ecu over-fuels for a given correction that means it was told the injectors were too small. Why small? well if it thinks that it has 23lb/hr and it really has 40 lb/hr, i need to almost double a given pulse in order to duplicate the result of a 40 lb/hr given the 23 lb/hr. if i used this doubled pulse that the 23 lb/hr requires, the 40 lb/hr now runs in a doubled states and over-fuels the condition. when your close to the correct flow rate this over-fuel condition becomes a manageable percent and can be accounted for using this calibration method.

    Well how do i adjust the offset data?
    thats pretty easy to do as well. i suggest starting by driving around as normal with a tuned in maf. all we want to do here is record the trim/afr error in a histogram matching the voltage offset table and in a similar histogram record the average injector ms. once you have an error percent you can correlate that to a ms <--> duty cycle. use this equation (rpm X inj ms /1200 = inj duty %) once you know the percent its operating at and the error in %, you can use this formula (inj duty % + error% = new inj duty %) back-solve the first equation using the new inj duty % to find a new ms. the difference between the old and new ms is now your new offset value.

    when you need to test the lower voltage cells you can disconnect the alternator output wire and drive around. try not to let this go bellow 11.4 volts for extended time or you can cause permanent damage to the battery. I have modified harnesses before to include a varying resistor so i can change just the injector voltage and monitor it through a volt gauge remotely but i dont suggest modifying harnesses at a whim when you can just source a correct injector set. if the offset test yields a considerable amount of cells that report a negative ms offset then you need to go back to the IFR table and increase the IFR values by a little bit so that they land in an under-fueled state. now all the offset calculations should go positive and allow voltage offset to be calibrated. (this is because the E78 does not allow (-) negative ms offset values.

    I have gotten grief for this method in the past but it calibrates the injectors exactly to the ecu parameters external to the fuel system. This means all those other systems dont usually have to be revisited and the fuel control becomes really smooth. This process is an iterative process since you have to redo the test process after every change, so if you dont have time to spare trying it then you can just disregard this post.
    Last edited by cobaltssoverbooster; 11-12-2019 at 10:07 PM.
    2000 Ford Mustang - Top Sportsman

  11. #11
    Wow, awesome information! Thanks for sharing the method. I think I'm going to give it a shot

  12. #12
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    Oh sweet! My bad for not checking. I didn't think anyone would respond! I am so glad you guys came through with the info. I will give it a shot sometime this weekend maybe. I am in the process of redoing my VVE from stock. I couldn't even get the car to idle properly, but I doubt I had the injectors set up right in the first place (I haven't touched anything like that as far as tuning since like 2005 and that was using Crome on an old chipped Honda. lol).

    Thanks so much for all of the info!