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I have to pull 15" or more manifold vacuum for mud racing what to do

Discussion in 'The Garage' started by strokerace, Mar 2, 2004.

  1. strokerace

    strokerace Registered Member

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    I have to pull 15\" or more manifold vacuum for mud racing what to do

    I have to pull 15" or more manifold vacuum for CMA mud racing what to do I have a chevy 350 with a 4 speed what shoud I run for manifold carb and cam for the best combo Thanks /forums/images/graemlins/confused.gif /forums/images/graemlins/thinking.gif
    STROKERACE
     
  2. justinf

    justinf 1/2 ton status

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    Re: I have to pull 15\" or more manifold vacuum for mud racing what to do

    When I used to mud race, we also had to pull 15" vacuum at 800 rpm. Is your motor stock or is it built? If it's stock you should pull 15" just fine. I used to run a modified Q-jet on stock intake with a pretty wild Lunati cam. Typically if you talk to the cam manufacturer's and tell them what you need to pull for vacuum and what other mods you have done, they can recommend a cam that will pull the vacuum you need. Also, you can run a variable lifter that can be adjusted to pull more vacuum.
     
  3. strokerace

    strokerace Registered Member

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    Re: I have to pull 15\" or more manifold vacuum for mud racing what to do

    its all stock except intake wich is a perforer
     
  4. cybrfire

    cybrfire 1 ton status Vendor GMOTM Winner

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    Re: I have to pull 15\" or more manifold vacuum for mud racing what to do

    The performer intake shouldn't be enough to knock you out of the stock class which is what you are looking to get in, I assume. What does it pull for vaccum now?
     
  5. strokerace

    strokerace Registered Member

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    Re: I have to pull 15\" or more manifold vacuum for mud racing what to do

    I dont now but it has to be 15" @ 900rpm I am runing in street stock so I can have some mods /forums/images/graemlins/grin.gif
     
  6. justinf

    justinf 1/2 ton status

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    Re: I have to pull 15\" or more manifold vacuum for mud racing what to do

    I would have to say you should be able to pull 15" of vacuum pretty easily. If you are worried about it, you can get a vacuum gauge fairly cheap and see what you are pulling. If you adjust the throttle mixture screws on the carb, you can also boost vacuum. Just run them in a ways and slowly start turning them out until you reach a peak in the vacuum, then adjust the other, keep going back and forth until it's pulling the vacuum you want. I would then suggest driving it to make sure it's not running too rich or too lean.
     
  7. HarryH3

    HarryH3 1 ton status Author

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    Re: I have to pull 15\" or more manifold vacuum for mud racing what to do

    It depends on where you live. Up here a stock rig is doing good to pull 17 inches at idle. /forums/images/graemlins/shocked.gif My 383 has a pretty mild cam but only pulls around 12 inches at 7,000 feet above sea level.
     
  8. bluebomber

    bluebomber Newbie

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    Re: I have to pull 15\" or more manifold vacuum for mud racing what to do

    I race dirt track stock cars and many classes have vac rules. Just call any cam company tell them what you have and the rules and they will tell you what cam you need.
     
  9. strokerace

    strokerace Registered Member

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    Re: I have to pull 15\" or more manifold vacuum for mud racing what to do

    I live in a small town in Wisconsin bye Minneapolis Minnesota I wish they woud let us run a stroker in the class Im racing thay do in other classis but it woud be hard to compete with out a lot of $$$$$$
     

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