Running a larger injector than necessary?

Discussion in 'Modifications & DIY how-to' started by Slowsoul, Aug 9, 2007.

  1. Slowsoul

    Slowsoul Member

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    I am still learning, so this might seem like a silly question but

    Is it a problem to run larger injectors than necessary for a given application?

    I am running the stock TD04 along with a TBE, up pipe, STi TMIC, and pro tuned AP. I would eventually like to upgrade to a VF series turbo, and I will be installing the OEM pinks...could I go ahead and install the pinks and get that step out of the way, along with the fuel pump, or will I run in to AFR problems? Would the pinks be too much injector for my current set up...is there such a thing, why, help?

    Elighten me.
     
    #1 Slowsoul, Aug 9, 2007
    Last edited: Aug 9, 2007
  2. FACE

    FACE Active Member

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    I would not think so if your installing OEM pinks...ask Ped or Alex...

    The only stupid question is the one you don't ask!!!

    Good luck
     
  3. Slowsoul

    Slowsoul Member

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    right...I guess it is just a learned response...too much nasioc. ;-)
     
  4. wrxin8or

    wrxin8or Mullitt
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    you will need a retune for new injectors...but if your stock injectors are no where near the limits of IDC's, then why waste the money on a retune when you are just going to get retuned when you get the new turbo in?
     
  5. Slowsoul

    Slowsoul Member

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    Yeah, that is a good point.

    I was just trying to get as much out of the way as I could before installing the turbo, but f I would have to get a retune to run the pinks with my current set up, and then have to get another tune when I installed the turbo, then it wouldn't be worth intalling them ahead of time at all.
     
    #5 Slowsoul, Aug 9, 2007
    Last edited: Aug 9, 2007
  6. Kokopelli

    Kokopelli Active Member

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    It is not a bad idea to go ahead and buy them now if you have a good oppurtunity, but you might as well wait to install them until you have the turbo and fuel pump
     
  7. miloman

    miloman Retired Admin

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    I have heard that running too big an injector is not a good idea because the spray pattern might not be too good if it is backed off too much :dunno:

    But something within the general vicinity would work as long as it has been tuned for.
     
  8. wrxin8or

    wrxin8or Mullitt
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    he speaks the truth...I just didnt want to see you have to get retuned twice...thats an expensive undertaking...
     
  9. Jake

    Jake Active Member

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    yeah i am running modded wrx injectors on a VF39. but scott put a base map/temporary reflash on there. your car WONT run right with larger injectors.
     
  10. Slowsoul

    Slowsoul Member

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    Thanks everyone.
     
  11. goixiz

    goixiz Active Member

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    ask your tuner or log your current setup
    if you are in the mid 80s to low 90s % FIDC then you are fine and dont need a retune

    you need retune for a new FI
    same thing as opening the tap
     
  12. crashtke

    crashtke Member
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    I do think you would probably be ok though if you wanted to use some method to tune it...Enginuity maybe?...I mean I am hitting 99% on my stock turbo with stock injectors at 17 psi...you are not adding that much it is only a 30% increase in flow. Personally I think that the stock injectors are a little weak compared to the efficiency range of the stock turbo...you can crank it up to 21 psi if you don't mind a short life span. Mine has seen 19 on a regular basis and started to get angry. If you are already stage 2 you will be pretty close to 93% now on stock injectors at 15.8 psi. Running the pinks at 63% should not be a huge deal.
     
    #12 crashtke, Aug 10, 2007
    Last edited: Aug 10, 2007
  13. goixiz

    goixiz Active Member

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    OP i believe is runnning AP and cant use OS tuning to change ROM
     
  14. Slowsoul

    Slowsoul Member

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    This is what I was thinking...and it is why I asked the question. My AP is tuned and my peak boost is set at 19psi, so my injectors are most likely maxed out, but I don't know. I am a MAC guy and I don't have a spare PC laptop to log with...I should pick up a cheap one. I really want to start learning more about tuning in general, I am sure that it would answer a lot of my questions if I just understood more about it all.

    At the end of the day, it really is not that big of a deal to me, I was mainly just curious...but it sounds like that it would be more of a headache to install the pinks ahead of the turbo than just waiting and doing them at the sametime.
     
    #14 Slowsoul, Aug 10, 2007
    Last edited: Aug 10, 2007
  15. crashtke

    crashtke Member
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    Here is an idea...if you are wanting to learn more about tuning, pick up a copy of ST, have your tuner switch the pro tune map to a ST file and for $195 you could have it all work just fine AND learn more about how your car works. I guess I have always liked learning more about it and you can still have your car pro-tuned with ST. I have not talked to a tuner yet that is unwilling to convert their files to ST format.
     
  16. Slowsoul

    Slowsoul Member

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    That is what I want to do. I didn't know that the files had to be converted, thank you for pointing that out. I first need to get my hands on a spare laptop, which shouldn't be too hard to come by.
     

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