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Thread: injector swap question

  1. #1
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    Default injector swap question

    Hi there i have a set of 60lb vdo siemens injectors withe the following specs


    •Coil Resistance: 12.5 Ohms / High Impedance / High-Z (No ECM driver modifications required)
    •Static Flow Rate @ 43.5PSI ( 300kPa ) w/Gas: 60 lb/hr = 630 cc/min = 453 g/min
    •Static Flow Rate @ 87PSI ( 600kPa ) w/Gas: 85.7 lb/hr = 900 cc/min = 648 g/min
    •Gain: 0.11ms/mg
    •Offset: 0.055ms
    •Turn on time @ 14VDC: 1.14ms
    •Turn off time: 0.85ms @ 600KPa

    what do i need to do to change the injector specs to suit for an ls1b ecu?
    The only thing i can see so far that correlates to the parameter chart is the turn off time so i have changed that from 0.7969 to 0.85 but am unsure what to do from here, any help would be great cheers.
    Last edited by vcls1; March 18th, 2012 at 02:03 AM. Reason: forgot some info

  2. #2
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    these are for a ls1b ecu by the way and at the moment will be used on a ls1 with a cam and head package, im aware that they are fairly large for a N/A engine however i am considering running e85 at some stage and am in the process of gathering parts for a rear mount turbo setup which i will be installing once i have some experience with efi live as i have ony just started with the program earlier this year.
    As for now i am wanting just to set them up for the N/A application.

  3. #3
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    my bad i was looking at the wrong tune file the one i was looking at was for an e40 not an ls1 b the ls1b paramaters dont even show a turn off time in the parameters only small pulse threshold.

  4. #4
    Joe (Moderator) joecar's Avatar
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    Use this spreadsheet to calculate your IFR table (B4001): http://www.marcintology.com/tuning/injectors.xls

    [ insputs: measured rail pressure should be 58 psi; rated pressure = 43.5 psi; rated flow rate = 60 lb/hr = 7.56 g/s ]

    Is your FPR un-referenced...?

  5. #5
    Joe (Moderator) joecar's Avatar
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    For E85, set B3601 Stoich AFR to 9.76;

    then check:
    - trims at part throttle;
    - sufficiently rich at WOT;
    - injector duty cycle stays less then 80% or 85% at WOT as you sweep up to your max RPM (use the INJxDC pids that depend on the IBPWx pids)..

  6. #6
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    hi Joe cheers for the reply my fpr is a rising rate vacuum referenced type, being a referenced type the rail pressure should be fairly constant throughout the rev range right?
    Last edited by vcls1; March 19th, 2012 at 02:58 AM. Reason: more to add

  7. #7
    Joe (Moderator) joecar's Avatar
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    If the FPR is manifold/vacuum referenced then the rail pressure rises with MAP...

    this means that the pressure difference across any one injector is constant (MAP above the injector cancels out MAP below the injector)...

    this means that your IFR table will be flat (same flowrate value in all cells, i.e. the 0 kPa MANVAC flowrate).

  8. #8
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    gotcha sweet as cheers

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