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ball bearing turbo,what size oil restrictor?

Discussion in 'Forced Induction' started by INJEN78, Feb 22, 2011.

  1. INJEN78

    INJEN78 HS LEGEND

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    my friend is going to be running a normal t3/t4 turbo and doesnt want to blow the seals..so ive been checking around and ive HEARD that we should run a .035 oil restrictor with a ball bearing turbo...now ive searched and can not find this size restrictor..all i can find is .065 which ive heard is best for journal bearing turbo's because they require much more oil pressure for longevity...so what im wondering is


    1.WHAT SIZE OIL RESTRICTOR DO WE USE ON t3/t4 BALL BEARING TURBO
    2.WHERE CAN I FIND OIL RESTRICTOR KITS
  2. Briansol

    Briansol Admins Admin

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    you don't need a restictor if you run the right (-3an) size feed line.
  3. TurboMirage

    TurboMirage Finally boostin'

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    was just about to say that :)

    and if you need them you can get them on ebay. you dont want more than 35psi pressure running through the turbo. 1/16th should be ok and if too small you can always drill it out to 1/8th.
  4. INJEN78

    INJEN78 HS LEGEND

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    well idk what 3/8 oil line converts to -an wise but i do know that its got an 1/8npt fitting on the end for running an 1/8npt fitting.
  5. Briansol

    Briansol Admins Admin

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  6. INJEN78

    INJEN78 HS LEGEND

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    fuck so i guess im running a -6an hose..im def gonna get a restrictor then.
  7. INJEN78

    INJEN78 HS LEGEND

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    so im going to look around for a .035 restrictor..the only thing is ebay does not offer one that size,
  8. INJEN78

    INJEN78 HS LEGEND

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    so is 1/8npt cross referanced to -4an??
  9. Briansol

    Briansol Admins Admin

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    just replace "an" with "/16" and you get your size, ie 4/16" or 1/4"
  10. INJEN78

    INJEN78 HS LEGEND

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    so wtf do i get for an -an fitting??
  11. INJEN78

    INJEN78 HS LEGEND

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    can anyone help?? im new to this -an and npt bullshit...i was just told by some company that 1/8npt converts to -2an?!?!?!
    but i just looked in speedway motors magazine where they have size charts and 1/8npt is showing to be -4an...
  12. Briansol

    Briansol Admins Admin

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    they will almost never match.

    NPT is a fitting based on inside diameter of item it (most of the time) screws in to
    AN is fitting as measured on outside diameter of the hose it (most of the time) clamps on to

    AN Fitting Thread Size Chart

    so,

    think of NPT as the fitting that goes IN the hose and AN as the fitting that clamps on the outside of the hose.

    AN's are almost always used on the hose itself, where as the npt fitting goes into he block, or other 'tapped' item

    thickness of the hose itself will vary, thus an -6an hose may require any number of different fitting ends, depending on the hose thickness.


    At the end of the day, you can't build a feed/return line yourself cheaper than you can just to buy one, so, just buy one.
    Fast-Turbo Complete Turbo Oil Line Kit
  13. INJEN78

    INJEN78 HS LEGEND

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    this is the feed line kit that my friend is getting-
    37' 'TURBO OIL FEED LINE KIT 240SX KA24DET CA18DET S13 - eBay (item 270638408654 end time Mar-20-11 12:26:44 PDT)
    ...the female end fits the 1/8npt silver fitting...
    but he needs to run an oil restrictor because the line is too big(-6an)
    this is the oil restrictor which says its 1/8npt or -4an
    Oil feed Inlet Fitting -4 Build-in restrictor GT28/30/3 - eBay (item 370485308278 end time Feb-23-11 20:16:31 PST)

    all i need is for the oil restrictor to thread into the female end of the feed line..
    which is why im trying to figure out if 1/8npt really is -4an or if its something else?
  14. Briansol

    Briansol Admins Admin

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    As I tried to point out above, they don't directly correlate.

    Take this image.
    [​IMG]


    the white inside is the hose 'flow' hole. an NPT fitting would screw INTO this area, if it were threaded.

    If the black is the thickness of the hose, yellow is the AN size needed.

    But if blue is the hose thickness, the brown is the AN size needed

    ignore the red line, i forgot to fill that in :X but was meant to be a 3rd example of the same thing if it was filled out to that line.


    maybe this will help too:
    AN vs. NPT | Aeromotive


    If the turbo is a real GT series, or clone, you can try this:
    GT Ball Bearing Restrictor

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  15. INJEN78

    INJEN78 HS LEGEND

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    alright i finally get it!!! lol
    so now my dilemma is i need a .035 restrictor to run with my feedline kit.
  16. Briansol

    Briansol Admins Admin

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    click the last link above!
  17. INJEN78

    INJEN78 HS LEGEND

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    i did..i can get that on ebay...thats what ive been asking about this entire time.
  18. INJEN78

    INJEN78 HS LEGEND

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    ok so heres what its come to..im trying to figure out if this
    GT Ball Bearing Restrictor
    will fit the female adaptor on my feed line..
    the feed line has female 1/8npt threads
    but that restrictor is for i believe -3an..
  19. INJEN78

    INJEN78 HS LEGEND

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  20. Briansol

    Briansol Admins Admin

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    You need to measure what you have to match it up.

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