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Thread: IS TBI back?

  1. #16
    Super Moderator dave w's Avatar
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    Quote Originally Posted by daveosx View Post
    Yes I know the ECM is real slow but I was thinking of just picking up the ground signal off the TBI injectors.
    Rather than try and communicate with the ECM.
    More a electromechanical than a computer style power adder.
    Years ago I used a GM 3Bar map sensor to control boost enrichment on a turbo BMW with Ljetronic just added fuel with injectors in parallel with the stock ones.
    When boost came up the second set of injectors turned on used a VCO and an AND gate to control proportional fuel.
    Just AND the injector pulse with the VCO output for secondary injector control.
    Ok, you have SKILS, most members don't.

    For members who would like additional information on an "AND Gate" http://www.electronics-tutorials.ws/logic/logic_2.html along with information a Voltage Controlled Oscillator (VCO) http://www.falstad.com/circuit/e-vco.html

    What I find interesting is most of the early Supercharged Buick V6 applications used a resistor bypass system on the fuel pump when in boost, allowing full battery voltage when the supercharger bypass valve closed.

    dave w

  2. #17
    Fuel Injected!
    Join Date
    Oct 2012
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    Boynton Beach Florida
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    61
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    Quote Originally Posted by dave w View Post

    What I find interesting is most of the early Supercharged Buick V6 applications used a resistor bypass system on the fuel pump when in boost, allowing full battery voltage when the supercharger bypass valve closed.

    dave w
    Yep
    When you do this the fuel volume is lowered on the supply side.
    It will work, you slow the pump by running it below 9 volts it will sputter the fuel into the filter accumulate then flow to the regulator through and back to the return.
    When running full speed 13.8-14.4 volts the pump will flow more than the regulator can handle over pressurizing the fuel rail providing boost enrichment.

    When running gasoline these pumps would fail badly at the first signs of condensation leaving you stuck with no start.
    Gasohol can absorb up to 20% water and still act like bad fuel but run.
    In the case of the Buick T-Types with this set up most where long dead before the switch to current Gasohol.
    There was a lot of those Supercharged V6 3800 with the M90 charger in the junk yards early manifold popping at the junk yard for good donors was a weakly visit.
    M90 and M63 work well for 2.6 to 3.2 L four bangers nut we found that unless the car was hit the charger would be damaged from backfires.
    A couple of thinks happen on lean on GM cars first EST kicks in retarding timing second the fuel toys to go full on.
    This combo will detonate under the charger if the fuel supply is the cause of the lean condition. POP POP BANG SCREACH

    Early turbo charging was more seat of the pants than tech.
    3.jpg
    Most set up were blow throw carb hats the really brave or foolish use suction side carb flanges.
    Fire happened all the time.

    Hows this for a BiFuel home brew.
    DSC03724.jpg

    Hot RODS with turbos usually started with big KKK 26 or Garret 04 size compressors and diesel turbines.
    Oiling was always problematic.
    And yes you can use a belt driven GM power steering pump on the OUTPUT side of the oil lines to scavenge the oil from a diesel turbine cartridge. Smokeless.
    They spin up really slow and on a SBC 350 didn't make much boost till you got up to 3800 RPM then the HEI was limited to about 5800 RPM.
    You could get more RPM using an old points style distributor with pertronics ignitor (points eliminator) or I used a toyota CD coil with a crazy stiff NAPA echlin brass points kit.
    The problem was not enough dwell time on the coil and weak spark at higher RPM.
    If you could find an old flat head magneto setup you had gold.
    Last edited by daveosx; 01-01-2018 at 01:39 PM.
    Avatar is my motor 800 RPM 184ft Lbs Torque 18 inches x 18 inches x 9 inches thick external combustion engine.

    98 WS-6 full tube chassis rally car Aluminum Block LS2 (soon to be LSX 376)(in Storage)
    95 Suburban 6 inch drop, Pioneer DVD in Dash 5.7 TBI, 220cc 2.02x1.60 64cc heads, Stainless longtube headers 2.5 crossover 3 inch exhaust, LT-4 roller cam.
    2002 Seville STS

  3. #18
    Fuel Injected!
    Join Date
    Oct 2012
    Location
    Boynton Beach Florida
    Age
    61
    Posts
    83
    Posted a primer with schematics for the fuel adder I mentioned in my posts

    http://www.gearhead-efi.com/Fuel-Inj...sion-for-BOOST
    Avatar is my motor 800 RPM 184ft Lbs Torque 18 inches x 18 inches x 9 inches thick external combustion engine.

    98 WS-6 full tube chassis rally car Aluminum Block LS2 (soon to be LSX 376)(in Storage)
    95 Suburban 6 inch drop, Pioneer DVD in Dash 5.7 TBI, 220cc 2.02x1.60 64cc heads, Stainless longtube headers 2.5 crossover 3 inch exhaust, LT-4 roller cam.
    2002 Seville STS

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