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Thread: trans brake to activate single stag nos and msd 8972 multi step retard?.

  1. #1
    dtcrawford Guest

    Default trans brake to activate single stag nos and msd 8972 multi step retard?.

    I'm looking for a wiring diagram. How to activate my single stage N.O.S system and a MSD 8972 multi step retard, when I release my trans brake. I would like both activations to happen when I release the trans brake, if thats possible?. As of now the multi step is on a toggle switch taking out 11* so total timing is 29* the car just stumbles when I release the trans brake.I'm not activating the NOS system yet. Thats not enough timing to leave with. Thankyou for Your Help its greatly appreciated.

  2. #2
    msdtech1955 Guest

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    Quote Originally Posted by dtcrawford View Post
    I'm looking for a wiring diagram. How to activate my single stage N.O.S system and a MSD 8972 multi step retard, when I release my trans brake. I would like both activations to happen when I release the trans brake, if thats possible?. As of now the multi step is on a toggle switch taking out 11* so total timing is 29* the car just stumbles when I release the trans brake.I'm not activating the NOS system yet. Thats not enough timing to leave with. Thankyou for Your Help its greatly appreciated.
    how much nitrous are you using ?

    web-nitrous-retard-twostep-.jpg

  3. #3
    dtcrawford Guest

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    275 HP shot for now, then possibly 325 no more than that. Its a Big Shot N.O.S plate system. Thankyou for your help.

  4. #4
    msdtech1955 Guest

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    normally, its 2 degrees retard for every 50hp ....

    the car just stumbles when I release the trans brake.I'm not activating the NOS system yet. Thats not enough timing to leave with. Thankyou for Your Help its greatly
    did we check to see if the fuel is "slushing" back thru the vent tubes and pouring disrectly into the motor ?

  5. #5
    dtcrawford Guest

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    no, I didnt check that if the fuel was "slushing" into the motor. The car never acted like that "stumbles" when just leaving on motor with trans brake.
    Thankyou for your help.

  6. #6
    msdtech1955 Guest

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    how is it wired ? can you post a drawing..?

    maybe the fuel solenoid came on?

  7. #7
    dtcrawford Guest

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    Taking a more thorough look at the wiring diagram you sent, i'll be wiring the timing computer to the nitrous solenoid per diagram, so all the timing is taken out when the nitrous switch is activated. I will be eliminating the toggle switch , which takes out all of the timing prior to N.O.S switch activation.
    Again thankyou very much for your help.

  8. #8
    dtcrawford Guest

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    I have the multi step retard wired to a toggle switch, the multi step is grounded until I turn on the switch, 12v volts is applied to the first stage and second stage for a total of 11* of retard.
    I have one more question. I'm using a dedicated fuel line with a Mallory 140 and reg. to feed the NOS fuel solenoid, with a Hobbs fuel safety switch set at 5.5 psi., before the NOS fuel solenoid. My question is, Has there been any known problems when using a Hobbs switch with the multi stage retard and a dedicated fuel line, since no fuel is flowing past the switch until pump is activated will this cause all the timing to retard when not using the NOS?. Thankyou very much for your Help.

  9. #9
    msdtech1955 Guest

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    I have the multi step retard wired to a toggle switch, the multi step is grounded until I turn on the switch, 12v volts is applied to the first stage and second stage for a total of 11* of retard

    so ,your putting 12 volts to the retard stages..

  10. #10
    dtcrawford Guest

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    Yes. when I turn the toggle switch it applies 12 volts, did it that way for peace of mind, so i know the timing is retarded when i hear the rpm drop.

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