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Thread: Going for overall efficiency

  1. #1
    Potential Tuner
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    Going for overall efficiency

    I have an L86/8l90e combo thats going in a project I'm using for lite commercial use. I already know I'm doing the AFM delete/tune, and will be non smog. 4.88 gears/33" tires. I will need low end torque over HP. Would deleting the vvt and going regular cam be worth it? In conjunction with headers? Most people focus is bigger power numbers but hopefully someone can chime in. Adjusting the axle ratio for lower rpm is not out of the question. Gross combined weight about 20k when loaded, half that empty. Thanks

  2. #2
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    Don't think you'll make more low end torque with a cam swap. I would zero out VVT retard under 2800 RPM. That will increase dynamic compression (cylinder pressure) and give you a bit more low speed, part-throttle torque. That's a lot of weight to move! But 4.88 rear with 4.56 first in the trans should get it done. I wouldn't go any higher (numerically lower) though. Don't fear the gear! @ 70 MPH with a 4.88 R&P and 33s you'll only be turning ~2300 RPM.

    Load mostly dictates fuel economy not RPM.

  3. #3
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    Thanks for the tip 👍

  4. #4
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    On 89 octane, do you think 8 mpg loaded,12 unloaded might be possible at 60-65 (pending aerodynamics)?

  5. #5
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    I'd be making a wild guess!! 20k is a lot of weight! Your estimate is probably close.

    These engines never cease to amaze me with how efficient they are at part throttle! In my 4x4 L86 Silverado I can easily nail down 21-22 mpg on a road trip. AFM disabled of course.