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Thread: Depitch?

  1. #1
    Chrisx88's Avatar
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    Depitch?

    05 RXT

    All the usual upgraded mods. Running 15/21 prop. 50 water temp, 57 air temp. Hitting 8200. Tune set @ 8800.

    if 1mm bend = 100-130 RPMS, than i would need 3-4mm? Can you pitch a prop that far? Should i buy a 14/19 and go from there?

    Edit:

    05 RXT
    Intake
    Exhaust
    xcharger
    80lb injector
    racelab tune
    Dynojet CMD
    Intake grate


  2. #2

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    15/19...go from there

  3. #3
    Chrisx88's Avatar
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    I think i want to go down on leading edge too. My hole shot is ass.

  4. #4

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    What speeds are you seeing with that prop and rpm?
    Can I ask why your using 80lb injectors? I have about the same mods and Jesus suggested I use 60lb?

  5. #5
    Cosmicbrut's Avatar
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    In my experience the max you can take out or add to a prop is 2 degrees on the leading edge 2 degrees on the trailing edge. A lot of props come with a slightly different pitch than advertised as well.

  6. #6
    SplishSplash's Avatar
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    If your going to bend the prop, only take out a mm to start on the trailing edge. 3 mm is too much.

    Reason, your at 8200 rpm now, if you take out 1 mm that will get you to 8400 rpm, but more importantly you have gained a lot of supercharger speed and thus more boost. So more power and you will be suprised at the gains (you may see 8600 rpm with just the 1 mm)

    I was in the same boat, 8200 rpm, and was targeting 8600, so 2 mm sounded right but was way too much.

    As for the weak holeshot, with no RRFPR, your probably pig rich down low with such big injectors.

    You hit a "sweet spot" with the X charger when you get into the higher rpms (over 8300) and the power comes on.

    Do a little at a time.

  7. #7
    Chrisx88's Avatar
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    Quote Originally Posted by SplishSplash View Post
    If your going to bend the prop, only take out a mm to start on the trailing edge. 3 mm is too much.

    Reason, your at 8200 rpm now, if you take out 1 mm that will get you to 8400 rpm, but more importantly you have gained a lot of supercharger speed and thus more boost. So more power and you will be suprised at the gains (you may see 8600 rpm with just the 1 mm)

    I was in the same boat, 8200 rpm, and was targeting 8600, so 2 mm sounded right but was way too much.

    As for the weak holeshot, with no RRFPR, your probably pig rich down low with such big injectors.

    You hit a "sweet spot" with the X charger when you get into the higher rpms (over 8300) and the power comes on.

    Do a little at a time.
    Should i do 1mm start on leading and trailing?

    I do have rrfpr. My Afr is 12.5 at idle. Im still tweaking fuel map, so i will check and see if its adding too much accel fuel.

  8. #8
    Chrisx88's Avatar
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    Pulled impeller today, its a 15/20, dunno why i thought 15/21.

    I couldnt tell wtf the trailing edge was at, matched up with 20 and 19. But i bent a little and tested. Got to 8300/8350. Im going to remove and bend a little more.

    Im also delaying when stabbing throttle, too much fuel. Forgot to bring laptop to adjust accel pum​p on CMD.

  9. #9
    Chrisx88's Avatar
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    Pulled pump, tried pitching again. Best i got was 8350 rpm.

    Suggestions on another prop to buy and try? I want 8600-8700 rpm

  10. #10
    SplishSplash's Avatar
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    Are you using the boost refernce line on the RRFPR?

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