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Modifying TBI for better fuel mileage?

Discussion in 'The Garage' started by joey90, Jan 17, 2004.

  1. joey90

    joey90 Registered Member

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    I've heard about people doing this and I was just wondering what's involved. I have a 350.
     
  2. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Tune your rig up and put a new O2 sensor. Inflate your tires. Drive like you have an egg under your foot.
     
  3. Thunder

    Thunder 3/4 ton status

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    Go here: cfm-tech.com

    Get the Air flow enhancer and the 1/2" TB spacer. With good exhaust you can pick up up to 2 mpg and a nice little increase in power. There are other mods you can do to the TB but those I mentioned will increase the MPG the most..
    I am running both plus a lot of other mods. They both are a good cheap bolt on power adder for under $100.
     
  4. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    [ QUOTE ]
    There are other mods you can do to the TB but those I mentioned will increase the MPG the most..


    [/ QUOTE ]Like what? I just bought another K5 that is an 87' and I wouldn't mind trying to increase fuel economy and power.
     
  5. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I can't see how a throttle body spacer is going to INCREASE economy. Generally anything that increases plenum volume is going to incresase fuel consumption. Not to mention what it does to your throttle cable and T/V cable if you have one. Those spacers get a big thumbs down from me.
     
  6. SUBFAN

    SUBFAN 1/2 ton status

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    So improving the engines efficiency by increasing torque output will not help? Having to use less throttle to get the same job done is a waist of time?

    Show me a post on here that has not been happy with their TB spacer? Readjusting the TV cable is a piece of cake.

    Mods to increase the engines efficiency, the breathing and driving style can and will increase mpg.

    A better flowing intake/exhaust system will improve the mpg's if properly sized.
     
  7. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    I have to agree with 84 chevy k10 on part of his response, using the TB spacer raises the TB about one inch or so and by doing so this changes the angularity of the operating range of the TV cable which now does not allow the TV cable to move through its proper arch which means it isn't going to work correctly and will burn up your transmission. However, if you make a new bracket or modify the existing one so that the TV cable will retain the original arch then it will increase performance and also slightly MPG.
     
  8. Thunder

    Thunder 3/4 ton status

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    [ QUOTE ]
    Like what? I just bought another K5 that is an 87' and I wouldn't mind trying to increase fuel economy and power.

    [/ QUOTE ]
    Heres a list of my mods on my stock 89 350 engine.

    K&N filter
    Air flow Enhancer and 1/2" TB spacer These were the first mods I did to it. Gave more power and better milage. Needed a minor readjustment of TV cable. Just had to let it out a few clicks.

    Injector spacer
    Flow matched injectors
    Adjustable fuel pressure regulator set to 14. psi. Put these mods on all at the same time. Because they require dissasembly of the TBI unit. Gave more power and made my truck run very smooth. Crisper acceleration,Lot More power on the top end. I can easly peg my spedo.

    Electronically Adjustable MAP sensor- Didn't really do much. helps a little around town with gas MPG but in the economy setting you dont have any power. Becaust it leans out the fuel curve. Just an electric gadget you prolly dont need.

    All the stuff above is available from CFM-Tech orhttp://www.turbocity.com


    Also have headers/flowmaster with no cat.

    In the ign dpt
    Dist module and coil from: http://www.performancedistributors.com
    And a stage 1 chip from http://www.fastchip.com

    All this stuff combined to give me a very good stout running 350. I get 18 mpg on the interstate. 12 -14 around town. On 33" MT tires with 3.73 GR. I dont drive all that easy. I like to hear my truck roar now and then.
    I use 89 0ctaine fuel. My truck runs like crap on regular gas.
    Hope this helps.
     
  9. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    Thanks for the suggestions. /forums/images/graemlins/smile.gif
     
  10. MA87K5

    MA87K5 1/2 ton status

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    I have an 87 with TBI and the TV cable moves with no bind what so ever. You are right about the angle though. As long as the cable casing isn't broken or the cable frayed, the cable shouldn't bind.
     

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