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Gas Prices driving Carb-TBI conversion

Discussion in 'The Garage' started by rcamacho, Apr 18, 2006.

  1. rcamacho

    rcamacho 1/2 ton status

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    I'm getting 8 MPG on my carb'd BBC. With the price of gas I'm half considering a TBI conversion but am a bit shocked by conversion costs.

    Assuming 8 MPG - 10 MPG, cost of gas is ~3.25 and say $1500 for the conversion it would take ~4000 miles to pay off?

    Anyone else on the board converting to EFI due to gas prices?
     
  2. 1979jimmy350

    1979jimmy350 1/2 ton status

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    1500 seems a little high for a TBI conversion, i only ended up spending 600-700 on my TPI conversion which tend to cost more than TBI
     
  3. moturbopar

    moturbopar 1/2 ton status

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    I think it depends on the carb you are using now. I have had good luck with Q-jets and tbi for ok fuel economy. I personally havnt seen a huge difference between the two (q-jet/tbi). I have had the opposite experience with edelbrocks and holleys, usually averaging a 1.5 mpg drop when I bolted them on. The only time I have ever picked up fuel economy on a holley was on a built 383 bb chrysler, The carb was built by brasswell and was almost $800!!! But it used anullar discharge boosters, had adjustable air bleeds and ton of other mods. I tried a bunch of different carb setups on the engine, The worst was a 750 holley dp which avereaged 7mpg, a q-jet(yes a q-jet on a mopar) and it averaged 9.5 ,and then the brasswell modded 750 dp, it went upto 12mpg. I thought about trying tbi on it but too much $$$$.

    is an overdrive trans a consideration also??
     
  4. rcamacho

    rcamacho 1/2 ton status

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    I'm running an NV4500 so OD is already in. It's the holley 3310-1 mpg which is killing me despite jetting the primaries down to #69. I'm going to throw an AFR guage on it to fine tune the primary main jets a bit more and get into the idle/intermediate circuits.
     
  5. 1985_K5_Silverado

    1985_K5_Silverado 1/2 ton status

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    How many miles do you drive it in a year?
     

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