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What mods can you do to a prius?

Discussion in 'Gen 3 Prius Accessories and Modifications' started by RobsF-350, Nov 25, 2009.

  1. donee

    donee New Member

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    This was a change done between the original THS (Toyota Hybrid System) and the HSD (Hybrid Synergy Drive, originally called THS II) which was what the second Generation Prius is running (starting late 2003 deliveries).

    The inverter doubles the voltage (from 208 v minimum) for driving the motor (500 Volt motor) , and then uses a charge pump for regeneration. As the motor is twice the battery voltage, regneration is advantagous down to 7 mph.

    The 12 V battery is far too small to accept any regeneration energy, other than by way of a switching power supply (very similar to a Personal Computer power supply) that runs off the hybrid battery.
     
  2. higuys

    higuys New Member

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    Incorrect dogfriend the chips do not modify the emission control system. The good tuners write 100% emissions legal tunes.

    The federal law dogfriend mentions is regarding the catalytic converter.

    Quit with the gas vehicle talk about simply leaning out the mixture. Diesel tuning is an entirely different application. There is far more to tuning a diesel than increasing timing and leaning the mixture. At least for the good tuners anyway.

    Bank's hypertech, edge, and the junk you see in the magazines and ebay are not good tuners. They are bottom of the barrel
     
  3. dogfriend

    dogfriend Human - Animal Hybrid

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    They need to test and certify to be road legal.

    No, it applies to any component of the emission system. The fuel metering system is considered to be part of the emission system on a fuel injected vehicle.

    http://www.epa.gov/oms/consumer/warr95fs.txt

    I gave you lean burn as an example of what you might "tune" to get max FE. It applies to gas fueled or diesel, but increases NOx on either. Anything that increases combustion temp will increase NOx.
     
  4. GWB1

    GWB1 New Member

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    Higuys wanted me to inform yall that he has passed not only visual emmisions testing. But OBDII scans as well.:D
     
  5. dogfriend

    dogfriend Human - Animal Hybrid

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    Good for him. It still isn't legal to modify the emission control system.
     
  6. GWB1

    GWB1 New Member

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    Well we can thank global warming for emission systems, oh wait.....

    and why would it be "illegal" if still passes the emissions test?
    (looking for a non-liberal answer)
     
  7. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    I deleted some of the way off-topic posts. In case you were looking for them.
     
  8. dogfriend

    dogfriend Human - Animal Hybrid

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    Actually, you can thank CARB (Calif Air Resources Board) for emission systems. Ever visit LA in the middle of Summer? I recommend the San Fernando Valley for the best example.

    Anyway, it would be illegal if the modification is not certified by the EPA.

    Back to the original question asked:

    The answer: They have to test and certify that the vehicle meets emission standards. They also have to guarantee that the emission control system functions for a certain period of time. So, they cannot allow you to screw around with stuff like FI timing and mixture and ignition timing and still be able to certify and guarantee the emission system.

    I don't really care (that much) if you screw around with it, but I'm glad you live in another state. :)
     
  9. RobsF-350

    RobsF-350 Powerstroker!!

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    Wow, this thread blew up.....
     
  10. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Wether it is Emmisions or speed limits or music, it is hard to reason with folks who want to do what they want to do. They don't WANT to beleive that "You have just not been caught yet" is not the same as "It is legal".
     
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  11. RobsF-350

    RobsF-350 Powerstroker!!

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    I agree, and one mod i have on my truck isnt legal. but in my defense, i did what i wanted to do to prevent future breakdowns. i havent had any breakdowns or other powertrain issues since i did this modification. i know ya'll dont agree with that but it fixed a problem from the factory without the dealerships help.
     
  12. RobH

    RobH Senior Member

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  13. dogfriend

    dogfriend Human - Animal Hybrid

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    I'm not the emission police, I'm just answering the question that was asked. :madgrin:
     
  14. dogfriend

    dogfriend Human - Animal Hybrid

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  15. GWB1

    GWB1 New Member

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    No, our trucks have a dual purpose. If I were to tow with my 140hp tune, I would melt my engine, Period. They have to be designed to fulfill both needs. If our trucks were never meant to tow they would come from the factory with a different "tune". I have 5 tunes for my truck and ALL of them make me get better fuel economy and I guarantee all of them would pass emissions.
     
  16. F8L

    F8L Protecting Habitat & AG Lands

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    Guess you never studied the multitude of negative effects fossil fuel emmisions have on public health, agriculture, environment, economy, etc.?
     
  17. dogfriend

    dogfriend Human - Animal Hybrid

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    It doesn't really matter how many purposes you have for your truck with respect to whether "tuning" is legal or not. :)
     
  18. efusco

    efusco Moderator Emeritus
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    While that's true, I'm not really sure it's that relevant.
    We install EV mods on our Prius that probably are, technically, illegal b/c they were not tested as part of the emissions controls (Gen II). Several have installed Thermister hacks that spoof the emissions control to think it's operating at a higher temp, clearly this would not be legal and assuredly negatively impacts the emissions control systems even while it improves FE. So let's not get too picky about something being technically legal or not.
     
  19. dogfriend

    dogfriend Human - Animal Hybrid

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    I already stated that I'm not the emission police, but at the same time, I'm just stating the facts according to my understanding. I think that you are correct that the EV mod could be considered an illegal mod.