Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

throttle body question

Discussion in 'The Garage' started by wasted wages, Sep 2, 2004.

  1. wasted wages

    wasted wages 3/4 ton status

    Joined:
    Dec 3, 2003
    Posts:
    9,194
    Likes Received:
    2
    Location:
    Dallas Texas
    Now stay with me,,,,

    Has anyone out there ever tried to wire two throttle
    body's to a single computer? I am wanting to do away with my carbs and don't want to spend all the $$$$ for a Hilborn setup if anyone has tried and made this combo work.

    Seems to me, two throttle body's wired together would fire the injectors at the same time with the first one having all of the
    sensors and throttle position sensor wired to the computer and the second one basicly acting as a slave unit.

    (something programable,, such as holley projection)

    I need 1500 to 1750 CFM so I figured maybe two T/B's might work,,,,,

    Ideas??? Comments??? /forums/images/graemlins/thinking.gif /forums/images/graemlins/thinking.gif /forums/images/graemlins/thinking.gif /forums/images/graemlins/thinking.gif
     
  2. K5MONSTERCHEV

    K5MONSTERCHEV 1/2 ton status

    Joined:
    Jan 27, 2003
    Posts:
    3,254
    Likes Received:
    0
    Location:
    Castro Valley, CA
    CRAP. Too bad you didnt ask this last week. There has been a car at the local car shows, he has 4 throttle bodies wired to gether, he had a modified stock plentum. it looked TRICK! /forums/images/graemlins/peace.gif
    To answer your question, yes it will work, im just not exactly sure how.
     
  3. tx_sub

    tx_sub 1/2 ton status

    Joined:
    Mar 5, 2004
    Posts:
    548
    Likes Received:
    0
    Location:
    Denton, TEXAS
    some of the tbi camaros had a dual tbi crossfire setup. i don't know what computer they ran off of. you should look on ebay for the setup or a parts car with it and get the whole harness and computer. i think turbo city also has some parts for the setup too. i wonder how that would work on a built small block. but then it may just be easier to do the mpfi elelbrock system when its all said and done. good luck
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,980
    Likes Received:
    189
    Location:
    Roy WA
    I believe it's "Grumpy" over on thirdgen.org forums (usually in the ECM section as I recall) that had done some work with the crossfire injection setup. (thats the twin throttle bodies)

    They were universally despised before, but I think a lot of whatever problems they had, have been worked through. No idea on flow, etc., but I kinda doubt they were nearly enough to feed what you are asking.

    Honestly, if you ask me, using two of something that are tied together is much worse than using one, if you can get one to work for you. Just like dual or triple carbs, getting them setup right, and keeping them like that, is much more difficult than a single piece.

    Not sure how GM got them to work together, but with injection being so "picky" on air/fuel mix, you could make yourself a lot of headaches trying to keep them working exactly the same.

    Of course, I have no personal experience in this, so if people have figured out how to make Crossfire "work", then there is obviously a way to do it. Just have to figure out how much effort it is, and compare to how easily you can use another system that will feed what you ask.
     
  5. Thunder

    Thunder 3/4 ton status

    Joined:
    Jul 20, 2000
    Posts:
    8,946
    Likes Received:
    1
    Location:
    Northeast Nevada
    I dont think you can get 1500 CFM out of 2 stock TBs. might be lucky to get 1250 out of 2 454 TBs. Holley units are 670 CFM so they wont get you there either.
    As said above The old Crossfire dual TBI set up was used by GM for a few years (82-84 I think). But because of the limited processing power of the early computers it did not handle mods very well. They can be upgraded and made to work better by using a newer style 90s TBI computer and wireing as a Master slave set up. Even with upgrades Crossfire will only support maby around 450 HP.
    Even if you could get the kind of flow numbers you need out of a crossfire dual TBI type system. You would have to be pretty good at burning chips and have access to a dyno to make it run right. Might bee cool tho if you have plenty of money to burn.

    If you are serious about running a high performance TBI set up check out this:BG VFI system
    It supports some pretty good HP nunbers.
     
  6. k20

    k20 3/4 ton status

    Joined:
    Sep 9, 2001
    Posts:
    5,068
    Likes Received:
    0
    Location:
    Mineral Springs, NC
    the 454 tbi's are 670cfm, but there is a guy on 454ss.com (JimD is his username) who bores out the stock bb tb's to (his claim) of around 8-900 cfm.
     
  7. wasted wages

    wasted wages 3/4 ton status

    Joined:
    Dec 3, 2003
    Posts:
    9,194
    Likes Received:
    2
    Location:
    Dallas Texas
  8. Thunder

    Thunder 3/4 ton status

    Joined:
    Jul 20, 2000
    Posts:
    8,946
    Likes Received:
    1
    Location:
    Northeast Nevada
    Are you going to run a Blower? Those hillborn FIs are for a 671 blower.
    If you are running a blower. TBI wont work very well for you unless ran with very low boost. Fuel delivery is controlled by a MAP sensor. Map sensors sense the vacume in the manifold. They dont work well when used with forced induction espically under high boost and will really screw up fuel delivery. The ECM can be programed to ignore the MAP and other sensors but you will have to spend some dyno=$$$$ time to get the fuel curve programed right.

    You prolly could build a TBI system if you know what you are doing with a flash programer for a lot less than what a Hillborne costs. But I dont know if it would run well enough to win races. The parts aren't all that expensive. The dyno would run you 600 or so. The problem may be finding someone who can program TBI chips if you dont know how. Not many people work with them anymore. /forums/images/graemlins/dunno.gif
     
  9. wasted wages

    wasted wages 3/4 ton status

    Joined:
    Dec 3, 2003
    Posts:
    9,194
    Likes Received:
    2
    Location:
    Dallas Texas

Share This Page