RPM Concern

Discussion in '6.7L PowerStroke Engine & Drivetrain' started by mjkruid, Jan 19, 2020.

  1. DaveBen

    DaveBen SDD Senior Member

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    QUOTE "At a lower RPM, your turbo is going to spin faster also." END QUOTE

    This is NOT true. Higher rpms generally mean your turbo spins FASTER.
     
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  2. kenter55

    kenter55 SDD Junior Member

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    Didn’t say that
    You’re going to downshift to drive any way right/ not be in overdrive, so gear to gear, the taller gears are going to “lug” the engine more making the turbo spin faster and likely wear out sooner. Thats all.
    That and leave well enough alone.
     
  3. bcvickers

    bcvickers SDD Junior Member

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    Can you elaborate on this statement more? I'm not understanding how lower RPM = higher turbo RPM. It is my understanding that they're directly proportional, not inversely proportional but please correct me if I'm wrong, I'm always open to learning.
     
  4. kenter55

    kenter55 SDD Junior Member

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    That is correct. When you change the gears, as you stated, you will be putting a greater load on the engine, just as if you shifted to a higher gear on a bicycle, it would make it harder to peddle. More load on the engine = more heat and expansion of exhaust gases, which in turn means more turbo RPM. Granted; this is if you drive it in the same transmission speed like 5th or direct (no Overdrive).
     
  5. kenter55

    kenter55 SDD Junior Member

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    Also, you will see a higher boost reading on your gauge, if you have one, which means more heat on your pistons
     
  6. kenter55

    kenter55 SDD Junior Member

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    PS in case it wasn’t clear, yes there is an inverse relationship between engine RPM’s and turbo ROM’s because of a gear change, all else remaining the same.
     
  7. kenter55

    kenter55 SDD Junior Member

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    Generally yes, but not when the change in RPM’s is because of increased load, as in higher gears. With the same load and transmission speed, of course
     

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