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Thread: How to tune 60lb injectors - 56k = ZZzzzzz...

  1. #21
    Advanced Tuner SJSchafer's Avatar
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    Quote Originally Posted by Rodimus_Prime
    why not just set the short pulse limit to like .25? whats the point in putting it at 1 then doing all this other stuff
    The short pulse limit just tells the ECM when to look at the adder table. Setting it to .25 wouldn't help. It would be counter productive.
    '07 Cobalt SS/SC
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  2. #22
    1. Any input on the relationship between offset tables and fuel rail pressure?

    2. Not just the 60's but is there ANY data readily available out there for offsets on other injectors?
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  3. #23
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    Quote Originally Posted by BennyHHR
    1. Any input on the relationship between offset tables and fuel rail pressure?

    2. Not just the 60's but is there ANY data readily available out there for offsets on other injectors?
    Absolutely. The offset table that I provided is for a rail pressure of 58spi. If your rail pressure is more you convert psi to kPa and adjust your table accordingly. Remember that increase in vac raises the pressure differential increase in boost lowers pressure differential. You may have to extrapolate the trend to fill in the spots at either end of the table, but that is not really hard.

    I have offsets for the stage 2 injectors as well.
    '07 Cobalt SS/SC
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    How to tune for return fuel system <--click

  4. #24
    Thanks for the response and all the other info you've provided here!

    My problem is that I'm trying to get the offset tables right for some Ford Bosch injectors. I have some offset data, but that's for Ford's 39.15 psi. My rail is 58 psi. Hence the question about pressures vs. offsets. I've already taken the limited Ford/Bosch data and extrapolated the tables, am getting close, but still is not all right. I have a feeling that the pressure effect is skewing the numbers and, if I can corrolate the two, things should start falling into place.

    BTW, this is replacing the 24# with 41.5# in a LE% / E67. I want to get the fueling dialed in before doing a SC install. Since I have to fab a custom intake, I know air (MAF cal) will have to be dealt with, too. But, having the fuel right will make the rest much easier.
    ____________________________________

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  5. #25
    Advanced Tuner SJSchafer's Avatar
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    Quote Originally Posted by BennyHHR
    Thanks for the response and all the other info you've provided here!

    My problem is that I'm trying to get the offset tables right for some Ford Bosch injectors. I have some offset data, but that's for Ford's 39.15 psi. My rail is 58 psi. Hence the question about pressures vs. offsets. I've already taken the limited Ford/Bosch data and extrapolated the tables, am getting close, but still is not all right. I have a feeling that the pressure effect is skewing the numbers and, if I can corrolate the two, things should start falling into place.

    BTW, this is replacing the 24# with 41.5# in a LE% / E67. I want to get the fueling dialed in before doing a SC install. Since I have to fab a custom intake, I know air (MAF cal) will have to be dealt with, too. But, having the fuel right will make the rest much easier.
    Indeed it would. I do not have the offset data for those injectors, sorry. If the offsets at that psi have a scale, you can get close:

    58-39.5=18.5, so you will be running these injectors at 18.5 psi more that the offset ratings that you have. 18.5 psi=127.55kPa. Plot the numbers to trend what they do as they increase in vacuum. 127kPa vac will be your base. Make sense?
    '07 Cobalt SS/SC
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    How to tune for return fuel system <--click

  6. #26
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    Now, remember your excel spreadsheet? Add a new worksheet. Go to your adder table, highlight it and copy with labels. Paste to your new worksheet. Next, enter a formula to add the 2 together. Should look like this:



    could i have the rest of that table by chance?

  7. #27
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    Quote Originally Posted by italstalnprd86
    Now, remember your excel spreadsheet? Add a new worksheet. Go to your adder table, highlight it and copy with labels. Paste to your new worksheet. Next, enter a formula to add the 2 together. Should look like this:



    could i have the rest of that table by chance?
    Here you go:
    '07 Cobalt SS/SC
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    I has a couple.

    Questions about 60s? <-- click!
    How to tune for return fuel system <--click

  8. #28
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    thanks man, much appreciated

  9. #29
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    help.....

    the car is having some serious idle issues, and when you give it gas it dies..... id post the logs and tune, but i cannot figure out how to get them in the post.....can i email them to someone to look at for me?

  10. #30
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    Quote Originally Posted by italstalnprd86
    the car is having some serious idle issues, and when you give it gas it dies..... id post the logs and tune, but i cannot figure out how to get them in the post.....can i email them to someone to look at for me?
    reply to this post, go to the bottom where it says manage attachments and upload them.
    '07 Cobalt SS/SC
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    Questions about 60s? <-- click!
    How to tune for return fuel system <--click

  11. #31
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    jesus i just don't know where you get all the time do this stuff. Good info here......really good info. THANKS!

  12. #32
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    Quote Originally Posted by CHARGDSS
    jesus i just don't know where you get all the time do this stuff. Good info here......really good info. THANKS!
    easy, I don't sleep.
    '07 Cobalt SS/SC
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    I has a couple.

    Questions about 60s? <-- click!
    How to tune for return fuel system <--click

  13. #33
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    logs and tune

    here they are

    I have been playing with these for 3 days now, terrible idle, i think its a timing issue, as when i force the car into open loop it runs pretty strong, but as soon as it is closed loop it goes to crap....

    i do not have wideband yet, but am working on it, i basically compiled this tune using a few how toos, and a base stage 2 tune, I am running 60 lbs injectors, fujita intake, 2.8 pully, header, catless dp, cryo2, dual pass, cobra heat exchanger, gmpp exhaust, and range colder plugs. I also have meth injection, but it is not hooked up, as the car also dies when that sprays, i think the psi is set to high on the pump, it is the snow performance stage 2 kit

  14. #34
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    why is your stoich Afr so low..I belive it should be around 14.69971...Any input pros???? I think 14.000 is a bit low and on surges you may drop to the 13's which i belive is a bit rich for idle..but it's just a taught

  15. #35
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    Your offsets are too high and as 04redline04 said your stoich needs to be 14.7. try that for starters. I posted the tune here. DL it and steal the offset tables. Use my adder to start with as well.
    '07 Cobalt SS/SC
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  16. #36
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    tried that stuff today, still wont idle unless i force it into open loop, any other suggestions?

  17. #37
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    Quote Originally Posted by italstalnprd86
    tried that stuff today, still wont idle unless i force it into open loop, any other suggestions?
    Post the updated tune and a log of OL and if you can, a CL log. Something is not right here. Also, are your injectors flow matched? If so, what was the average static flow rate?

    Edit - I just looked at one of your previous logs. What kind of car do you have???? We only have 1 bank of trims.
    Last edited by SJSchafer; 05-15-2008 at 04:54 PM.
    '07 Cobalt SS/SC
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    I has a couple.

    Questions about 60s? <-- click!
    How to tune for return fuel system <--click

  18. #38
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    um its an 05 cobalt ss sc, however i have not set up the log stuff in hpt.....

  19. #39
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    Quote Originally Posted by italstalnprd86
    um its an 05 cobalt ss sc, however i have not set up the log stuff in hpt.....
    Okay... Ummm... How are you collecting data to tune your tables? Step 1 for HPTuners is to learn the scanner. It does TONS of stuff. If you don't have the right info, you can never get anywhere.
    '07 Cobalt SS/SC
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    I has a couple.

    Questions about 60s? <-- click!
    How to tune for return fuel system <--click

  20. #40
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    i ran the scanner, got some logs, and sent them to someone, they told me to find some tables, and adjust mine accordingly, thats what i did basically