Dual TBI setup on Vortec 5.7?

Discussion in 'Engine Performance + Maintenance' started by Backtobasics, Sep 22, 2010.

  1. Backtobasics

    Backtobasics Newbie

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    I am thinking about a dual 4 bbl intake manifold with TBI to square bore adapters, and running dual TBI units.

    94 Suburban 1/2 2wd. I am replacing the blown 5.7 that came in the truck, with a standard 5.7 TBI for now.

    I am contemplating rebuilding the stock 5.7 and going to a 383, with performance cam, rebuilt and port the heads, etc.

    Research says that even a "Turbo City" rebuilt TBI runs 590 CFM compared to 520 CFM in stock configuration.

    I have not seen a "Vortec" pattern intake manifold in a dual carb configuration. I know "Professional Products" make adapters to allow a standard small block intake to be used on a Vortec application, so I could use an easily found dual quad intake manifold.

    What obstacles would I encounter trying to make the 2 throttle bodies work together?
     
  2. 1990GMCSIERRA

    1990GMCSIERRA I'm Awesome

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    find u a crossfire corvette they had the twin throttle body set up
     
  3. Backtobasics

    Backtobasics Newbie

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    I have heard that they are very problemmatic.
    I have seen several dual quad carb small block chevy intake manifold recently. Transadapt makes several adapters to go from 3 bolt TBI to square bore carb, and they even offer "front or back" positioning, to allow you to have the TBI up close to the front of the intake or more towards the back for spacing accomodations.
    Add a 2nd TBI from a salvage yard, and the main components are done, beyond linkage and fuel lines, which I can built with Aeroquip/Russell/Earls through work.

    My biggest question is injector firing, and sensor compatibility.
     
  4. 1990GMCSIERRA

    1990GMCSIERRA I'm Awesome

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    my dad always had trouble with it,thats why he sold it
    and ull need a computer tune afterwards or theres no way itl run right
    on a stock engine i really think ud be wasting ur time and money cuz ud prolly drownd it
    id just build u a motor
     
  5. DRAGGIN95

    DRAGGIN95 Warranty Killer! Staff Member

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    I always thought it would be fun to try out a dual tbi setup, but I am sure it would be more difficult to get dialed in.
     
  6. 1990GMCSIERRA

    1990GMCSIERRA I'm Awesome

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    dual carbs are hard enough to keep right
    and carbs are simple,
    o yea itd definatly be something eveyone one doesnt have
    plus itd be awful intimidating to somone if u pop the hood and uve got 2 throttle bodies sittin there
     
  7. MIHELA

    MIHELA Nooo! Noooooo

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    Dual carbs have to be set up individually. Dual TBI doesn't if you run it on a Megasquirt or some other programmable fuel injection. You would have to buy a dual carb Vortec manifold and 2 TBI adapters, and fab up a linkage and plumbing. I think it's totally do-able, and would give you better control over fuel than a single TBI.
     
  8. Crash

    Crash I'm Awesome

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    Nice $300 manifold
    Edelbrock 7526
    [​IMG]
     
  9. 1ugly88

    1ugly88 I'm Awesome

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  10. Problem2420

    Problem2420 I'm Awesome

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    thats sick!!
     

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