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87 oct with chip?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 90K5, Apr 14, 2001.

  1. 90K5

    90K5 1/2 ton status

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    I have a Hypertech Thermomaster chip on my K5, but I have to use premium with it. Do i really need to? I'm too poor to pay $1.80 for premium. I still have the old chip if i can only use premium with it, but I'll also have to change my thermostat back. Thanks

    90K5

    See my truck at <A target="_blank" HREF=http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502>http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502</A>
     
  2. Derf00

    Derf00 1/2 ton status

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    I recently installed the same chip in my '90 Jimmy. The guy I purchased it from said to test it out with regular fuel and without the t'stat. It works great, and I do not experience any detonation.

    Derf00
    http://www.derf00.coloradok5.com
    "Four wheel drive allows you to get stuck in a more inaccessible place."
     
  3. 90K5

    90K5 1/2 ton status

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    Did you notice any performance gains from the chip alone?

    90K5

    See my truck at <A target="_blank" HREF=http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502>http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502</A>
     
  4. 90K5

    90K5 1/2 ton status

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    I put about 20 gallons of 87 in today, so we'll see............

    90K5

    See my truck at <A target="_blank" HREF=http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502>http://albums.photopoint.com/j/Albumindex?u=1329584&a=9886502</A>
     
  5. HarryH3

    HarryH3 1 ton status Author

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    The engine should run fine on 87 octane, but you'll lose some of the advantages of having that chip. It comes with a pretty agressive timing curve programmed into it, which is why they recommend premium fuel. But the computer will retard the timing when the knock sensor "hears" the engine pinging to prevent engine damage. So even with the agressive timing of that chip, the computer should back the timing off to compensate for the lower octane fuel.

    <font color=black>HarryH3 - '75 K5</font color=black>
    <A target="_blank" HREF=http://ThunderTruck.ColoradoK5.com>http://ThunderTruck.ColoradoK5.com</A>
    It's a great day to be alive...
     
  6. sarazk5

    sarazk5 1/2 ton status

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    Be glad your premium is only 1.80 per gallon. Our 87 octane is up to 2.00 per gallon
     

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