Friday, June 12, 2009

0 rpm acceleration limited

One of the great things about electric cars is they have instant torque that means that when you press the accelerator you get a the full power of the motor immediately, think of it as having a car that is always at red line in the power curve, but without that hi pitched engine noise.
Normally when I'm driving the MINI E if I punch the accelerator, I immediately get a very quick burst of acceleration and have to hold onto the steering wheel as torque steer pulls the car heavily to the left. But at a stop, when I press on the accelerator, there is a noticeable half second delay before I get even the smallest amount of acceleration, and even then the acceleration isnt anything to write home about. Then once I get moving, maybe at 3mph or so, the full acceleration kicks in and I have to pull my foot back on the accelerator. This is a very fustrating experiance, for the MINI E's they removed the normal button that would allow you to disable traction control, and if it was the traction control system kicking in to keep the the tires from spinning I'd understand. But its not, this is the control software overly limiting your acceleration at low RPMs.
In a previous article on greencarreports.com John Voelcker mentioned this problem, it was also mentioned that the car may have been running an older version of the software. I hadnt noticed this problem in my pervious test drive, and since these cars have been sitting in storage for the last 6 months, I'm guessing they all have an older version of the software. I asked my service Rep, at Morristown MINI about getting the latest software and he said he'd look into it.
Hopefully this is just overly conservitive software and we can have a car thats as quick off the line as it is once moving.

4 comments:

  1. Robert,

    I agree with that. The car is normal off the line and then at 5to 10mph when you step on it it flys. I notice it but do not find it annoying.

    My guess is a programming code to keep us from breaking the mini parts whith too much off the line. (Thats why they keep the little box locked)

    If they can reprogram that would be awesome and much more fun!

    peder

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  2. First, you don't get the full power of the engine, because power=torque*revs
    What you actually have is almost the full torque of the engine.
    Electric motors having the full power, or even the full torque, from 0 rpm is just a misconception.
    Therefore, it's pretty obvious the car isn't moving as quickly as when you are revving it when you start from standing, because with 0 rpm, the power is null.
    Also, it's very likely that the software is limiting even more the ability of the E to start quickly so to avoid small accidents while maneuvering.

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  3. I heard someplace that the acceleration had to be toned down to work with the existing drivetrain which was not redesigned for the MINI E. I've only had a relatively short drive home so far but I haven't had any problems getting used to it.

    -Stu <<277>>
    http://www.stuartistry.com/my-mini-e

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  4. I definitely would like to see accelerate a bit more instantaneously from 0. So far this is the biggest issue for me. After that it's the Mini Rocket according to my son :-)

    Dominique (308)

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