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220HP ... when?

Discussion in 'Gen 5 Prius Main Forum' started by PriusPrimetime, Aug 14, 2023.

  1. Numtini

    Numtini Member

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    Supposedly EV mode tops out at 84MPH and the ICE then turns on.
     
  2. KMO

    KMO Senior Member

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    The 144km/h indicated would be 137km/h (85mph) actual - it reads +5%.

    MG1 has a 10000rpm limit, and if you work through the maths of the drivetrain gear ratios, to avoid exceeding that the engine has to start spinning above 135km/h or 84mph.

    Because Gen 5 has a more powerful engine and MG2 than Gen 4, its final drive ratio is lower, so MG1 and MG2 run a bit slower at any given speed.

    Hence the Gen 5 can go faster in EV mode than the Gen 4 before hitting the MG1 10000rpm limit, and it can also go a bit faster overall before hitting the MG2 17000rpm limit, which is why the speed limiter is 177km/h rather than 162km/h.
     
  3. Preebee

    Preebee Senior Member

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    Thanks a lot my friend!! Looks like the performance numbers are identical on the Prime with the battery charged, or depleted. That's interesting.

    Now I've gotta convert everything over to MPH!
     
    vvillovv likes this.
  4. vvillovv

    vvillovv Senior Member

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    Got me wondering what the amp draw is in EV at those speeds and rate of acceleration.
    I've seen DrPrius go from green to yellow than red once at 100 amps and around 350 volts once in the Gen 4 Prime, accelerating up an incline onto the hwy / interstate from around 10 mph around a sharp curve on the entrance.
    I've still never figured out how long the Prime will stay in EV at it's upper sped limit before it runs out of juice from the pack. My wild guess is somewhere between 10 - 15 minutes.
     
  5. Trollbait

    Trollbait It's a D&D thing

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    The EV icon is really an engine off light.

    This is the basic theory of efficient hybrid operation. An engine has a peak efficiency point. A traditional car with an engine that spends most of its time at that point isn't driveable; it can't climb hills and pass, and today's econo cars accelerate like race cars in comparison. A hybrid uses such a low power engine, and combines it with an electric side to make it driveable.

    The hybrid tries to keep the engine at that efficient peak. If the current drive conditions need less output, the system will run the engine into the efficient peak and use the excess output to charge the battery. Needs more, and energy comes out of the battery to power the traction motor. If it isn't possible to run the engine near that efficient spot, and there is enough charge in the battery, the car shuts off the engine.

    Which is when that EV light comes on, but it doesn't mean EV isn't used when it is off. In Toyota's system, some motor is always spinning, and electricity flowing while the engine is on..

    SAE has a standard for measuring hybrid system power that results in a number comparable to what is reported for a straight ICE or EV car. Not sure how Toyota is measuring it, but if it is only for a short time, then it isn't really the peak power. It is like reporting a turbo engined car's peak power plus any overboost power as the peak.

    A power-split hybrid like the Prius has an engine and two motors, MG1 and MG2. These are all the same between the hybrid and Prime. The Prime just has a clutch to allow the two motors to work together in EV mode, thus the higher EV hp rating. Simplified, MG2 is the traction motor that moves the car, and MG1 is the generator providing the electricity.

    The battery is tiny in hybrid, so MG1, the less powerful motor, is the limit on how much power MG2 adds to the system. The Prime loses that limit with the bigger battery. The 220hp is already reflecting that increased battery input. It's likely possible to pull more out. Just like it's possible to do so with an engine, but that usually results in trading off reliability.
     
    Numtini likes this.
  6. Preebee

    Preebee Senior Member

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    Not a very good one lol. It's usually late to the party when the ICE has already been off for a little while.
     
  7. vvillovv

    vvillovv Senior Member

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    That is sometimes because the Prime wants to make sure the engine is going to stay off for -some?- set amount of time and not be called for duty within a few seconds after shutting off the engine, when allowing the Prime to do the switch on it own, automatically.
    The EV dash light is johnny on the spot when pushing the HV/EV button and the engine can switch off on command and go straight into EV mode.

     
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  8. black_jmyntrn

    black_jmyntrn Senior Member

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    the M20a-FXS in the new Prius puts out 150hp and is the motor I'm installing in my 2013 PIP.

    the A25A-FXS is the motor ill be installing in my Gen 3 next. It has 189 hp, combined with the rear electric motor I'm adding that has ~268hp, I should have close to 500hp in a Gen 3 Prius getting great MPG!