Air Induction Hood - RPM Activated

Discussion in 'Project Progress' started by EricsZ28, Jul 23, 2012.

  1. EricsZ28

    EricsZ28 Veteran Member Lifetime Gold Member

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    EDIT: VIDEO Posted in 4th post...

    This is a VERY nice project for anyone with an air induction hood! I used an old MSD 8950 (from a board member) to control the flapper on my air induction hood. When the engine turns at the RPM indicated on the chip I've selected, the flapper opens.

    Previously, I thought these switches turned the power on and off. Not true. These switches provide a path to ground. This requires a new ground wire to be run to the hood solenoid - which usually just grounds to the hood. Here is the wiring diagram I used. Proceed with caution, don't hold me responsible, etc:

    [​IMG]
     
    Last edited: Jul 23, 2012
  2. EricsZ28

    EricsZ28 Veteran Member Lifetime Gold Member

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    To accomplish this, obviously, disconnect the battery, and run a new ground wire to the solenoid on the hood. Cut the existing ground wire and splice this new ground wire to the solenoids ground. Then, connect this ground wire to the yellow wire on the MSD 8950 switch (normally open ground). Then connect the MSD switche's power, ground, and tach signal wires. The tach signal typically comes from the negative coil wire. I added a shift light while I was doing this.

    Then, I ran a bypass on the switch wire at the accelerator pedal. I simply bypassed the switch with another wire to provide constant power. This bypass won't hurt anything when the switch activates at WOT.

    Like this:
    [​IMG]
     
  3. SupplySgt

    SupplySgt Veteran Member Lifetime Gold Member

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    I don't have one of these, however, this is a pretty interesting idea. I like the ingenuity of this. If I ever end up with one of these cars it would be an idea to use.
     
  4. EricsZ28

    EricsZ28 Veteran Member Lifetime Gold Member

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    And here it is (video, give it a few moments to load):
    [​IMG]
     
  5. SupplySgt

    SupplySgt Veteran Member Lifetime Gold Member

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    Ok after seeing the video, that is REALLY cool. I like it even more after seeing the video. If I had an 80 or 81 with that hood, I'd definitely do that mod.
     
  6. EricsZ28

    EricsZ28 Veteran Member Lifetime Gold Member

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    You'll notice I have a 3400 RPM chip in the switch right now. I panned out at one point so you could watch the tach and the hood.

    The hood on this car simply makes sense now when you drive it. As the RPM's increase, the demand for air increases, and hood opens. After driving it for a while yesterday, I'm quite pleased with the results :cool:

    Hopefully this gives somebody some ideas - and shows that it does work well :bowtie:
     
  7. EricsZ28

    EricsZ28 Veteran Member Lifetime Gold Member

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    Thanks bud. Yeah, this really gets the flap moving when you have a cam like mine which comes alive at 3k+ RPM's.
     
  8. mscamp02

    mscamp02 Veteran Member Lifetime Gold Member

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    subbed for much later
     
  9. CDesperado

    CDesperado Veteran Member Lifetime Gold Member

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    Thanks for posting this! This is identical to an idea we have been discussing on my car, but havent figured out how to do it yet. You just made my life a lot easier! LOL

    One other idea you may have considered and dropped... have you considered adding a timer delay switch that would control the amount of time the flapper is open? Or to be more specific, something that would allow the flapper to stay open a few extra seconds after the RPMs drop? For example, let's say your threshold is 3400 RPM. Once you hit that, the flap opens, but the delay switch would enable the flapper to stay open for a few extra seconds after the engine winds down past the RPM threshhold?

    I got this idea when I stumbled across a kit that adds a timed delay feature to the cabin lighting, where the lights stay on a few extra seconds after you close the door. I have no idea if something like that could be rigged up for the flapper though.
     
  10. EricsZ28

    EricsZ28 Veteran Member Lifetime Gold Member

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    I'm glad this was already helpful!

    Cool idea. I didn't think of that. It seems to me that this would be nice if you had the switch set to open at higher RPM's - where you shift, the RPM's drop, and the hood closes.

    I will admit that I kind of like the flapper opening and closing as I shift. For whatever reason, I really seem to notice it more now (obviously it opens up much more frequently now since you don't need to be at WOT).

    I was going to put in a 2800 or a 3200 RPM switch, but I was afraid it would be open more than it was closed. The 3400 set point seems to work real well. It doesn't open unless I'm hanging in gear a bit longer or unless I'm getting a bit lead-footed --- which is exactly when I want the flap to open.
     

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