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fuel injectors

Discussion in 'Forced Induction' started by SplitzO, Nov 21, 2006.

  1. SplitzO

    SplitzO Junior Member

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    Would RC 440cc injectors be good enough for a turbo lsvtec or crvtec? or should I go with something like 550. I am wanting to run pretty high boost. Like 18+
     
    Last edited: Nov 21, 2006
  2. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    go with 550 and if its to much just turn it down
     
  3. SplitzO

    SplitzO Junior Member

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    Alright sounds good thanks.
     
  4. pissedoffsol

    pissedoffsol RETIRED

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    440's support about 75hp per cyl.
    550's about 95 hp/cyl.

    psi means nothing.

    go against your power goal.
     
  5. turb2o_vtec

    turb2o_vtec New Member

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    I'll say at leat 750cc or higher.
     
  6. spoolin@idle

    spoolin@idle D Series FTL

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    baddabing. he speaks the truth. its all about the power numbers.

    Injectors and Fuel Supply

    click there, then scroll down and see the chart. and don't forget to add the 10% based on the duty cycle necessary for turbo setups.
     
  7. silver

    silver Senior Member

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    Or...

    Minimum Injector Size (READ NOTE ON BOTTOM) = [max airflow you want/expect (lbs/min)] / [AFR you want to run] x [454 g/lb] / [.76g/mL for pump gas] / [# of injector] / [max IDC you want to see]
    Or simplified:
    [max airflow you want/expect (lbs/min)] / [AFR you want to run] / [max IDC you want to see] x 149.34 (for 4 injectors)

    e.g. You want to flow 30 lbs/min and run a 10.5:1 AFR and want to keep your IDC below 80%.
    30 / 10.5 / 0.8 x 149.34 = 533 cc/min. Round up and you get 550 cc/min injectors.

    Taking note that 1 lb/min of airflow is roughly equivalent to 9-11 crank horsepower (so say 10), you can use this to estimate injector size based on your power goals.

    NOTE: The nature of these calculations are highly theoretical and thus you should apply a safety margin at all times when using these calculations. These calculations do not take into account every real world situation and there are about a billion things that could screw these numbers up. On the other hand, you get a good approximation of what you need. Always use a safety margin of 10-20% if you actually do use this (meaning divide your final answer by .90 or .80, meaning the above 533 cc/min would go to 592 cc/min or 666 (zomg!)cc/min depending on what you divided by).

    This also assumes that you run 43 psi base fuel pressure which is what almost every injector company gives out their ratings based on. E.g. RC 550cc injectors are meant to flow 550cc at 43 psi base. If your base fuel pressure is 33 then they will perform like 481cc injectors.
     
  8. TunerToys

    TunerToys Junior Member

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    Here are the basic number we use when suggesting injectors for our customers...

    Flow Rate vs. HP Level
    (Flow Rate for each injector,
    in a four cylinder setup.)

    310cc 200~220whp
    370cc 220~280whp
    440cc 280~330whp
    550cc 330whp~380whp
    660cc 380whp~425whp
    720cc 425whp~475whp
    880cc 475whp~525whp
    980cc 525whp~600whp
     
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