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ICE Compression when on battery only?

Discussion in 'Gen 2 Prius Technical Discussion' started by *Goldfinger*, Sep 22, 2014.

  1. *Goldfinger*

    *Goldfinger* Junior Member

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    If Prius has to constantly spin the ICE when over 42 mph, even when only running on battery power, it must waste a lot of energy overcoming ICE compression all the time. Or is there some kind of system to reduce compression in this situation – just curious :)
     
  2. bisco

    bisco cookie crumbler

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    i'll place my bet on valves open.
     
  3. *Goldfinger*

    *Goldfinger* Junior Member

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    Thats what I would have thought but as it's a chain driven cam I can't imagine how it is possible
     
  4. AzWxGuy

    AzWxGuy Weather Guy

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    I wager that the North American market Gen II ICE will run continuously above 41 mph with your foot on the gas. Coasting, different story. Still, I believe EV is not possible above 41 mph without ICE engaged, and that would not be EV. Interesting though, wonder if the variable valve timing, intelligent (VVTi) has an open valve position. Somebody must know.
     
  5. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Think of the cylinder as a spring, while it takes work to compress it, you get almost all that work back on the decompression. Altering the valve timing is possible.

    [​IMG]
     
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  6. *Goldfinger*

    *Goldfinger* Junior Member

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    Does the gen 2 Prius have VVT-I, mine is described as VV-I but I don't know what that stands for or means?
     
  7. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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  8. *Goldfinger*

    *Goldfinger* Junior Member

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  9. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    I suspect VV-i of being the buzzword in nations where VVT-i was already a trademark for some other company.
     
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  10. Data Daedalus

    Data Daedalus Senior Member

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    Amazing technology, Toyota's VVT-i.....seriously, if the "I hate Prii brigade" stopped for just one minute to investigate what really makes Prii tick, and makes them so unique and irresistible to us savvy owners.....they'd learn about one of the world's greatest motoring secrets.......and stop creating inane myths about it. :)
     
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  11. Mendel Leisk

    Mendel Leisk Senior Member

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    So is the Prius engine able to pretty much free-wheel with the engine running but no load? It feels very much like it's in Neutral, to me. My ScanGauge shows rpm (around 900) and zero fuel consumption, fwiw.
     
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