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NEW PHEV Install!

Discussion in 'Prius PHEV Plug-In Modifications' started by gasnippr, Dec 1, 2008.

  1. PeakOilGarage

    PeakOilGarage Nothing less than 99.9

    Joined:
    Oct 3, 2008
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    Vehicle:
    2009 Prius
    CARB is the agency in California that regulates air emmissions. They would only allow the Hymotion battery to be installed in California if the catalytic converter is warmed up every time the car starts. It is stupid really. If the car can go in pure EV mode for short trips, that is actually better for air quality.

    So Hymotion did a software update that meets the silly demands of CARB. The Hymotion batteries with this software version go through a 55 second warm-up phase no matter what. It is impossible to avoid it.

    That is one part of the software update. I believe there are other changes that deal with the 12 volt battery and the LED flashing.

    I like being able to go in pure EV mode from the start, so I am trying to avoid the software update if I can. I really have not had any flashing LED errors in about a month.
     
  2. donee

    donee New Member

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    III
    Hi PeakOil,

    SHM, or Super Highway Mode, is a method of cruising on the highway in a stock Prius where one gets about 70 mpg. On Cleanmpg.com, in the Prius section, you will see DAN 's writeup of it. He uses the IGN parameter to know when he is in it. It requires that the battery be 60 % SOC or greater. Shortly after this method was figured out, is when Wayne Gerdes took CBS up on their one-tank Chicago to NYC challenge, which he completed successfully. This is the technique Wayne used most of the trip on I80.

    As to a first order approximation Spark Advance (the IGN value in degrees) is tightly linked to engine RPM, I use engine RPM. I do not have a IGN indicator. My target in weather warmer than about 40 F, and on level road with no wind is to run the car at 53 mph, and 1280 RPM. One gets going a little faster than 53 mph, then brings the gas pedal back until 1280 rpm. The car will give a little push as it kinda drops into SHM mode. And the MPG's will jump up about 10 or so mpg to the low 70's. The next RPM quantum up is 1314 RPM, and the mileage will drop by 5 mpg if you let the car run at that RPM. Below 1280, (the next quantum down is 1248) the car will slow down below 53 mph. In warm weather, with 44/42 tires, the car will just hold 53 mph at 1280.
     
  3. PeakOilGarage

    PeakOilGarage Nothing less than 99.9

    Joined:
    Oct 3, 2008
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    Location:
    Pacific Northwest
    Vehicle:
    2009 Prius
    donee, very interesting info. Thanks for the explanation.