• Category Archives Smart Car
  • Add lightness

    It really is tough to add lightness. I know this from first hand experience.
    The Smart Car is mostly underpowered. It is fine for what it is designed for, putt putting around the suburbs, but that is not what I was looking for… I wanted a car that could be driven at 8/10s at legal speeds.

    I had two options. More power from the motor, or help the motor work less.
    Most people go the first route and add a turbo to the motor. The motor is very strong, it can take the extra boost from the turbo, but drivability then becomes an issue.
    The Smart car motor is 3 cylinder, 0.9 liter. It is the heart of a humming bird. In other words, it revs like crazy and loves doing that. Adding a turbo that only kicks in a higher revs is like feeding Red Bull to a humming bird. It works, but at the end of the day, it makes no difference. The thing is still spinning like nuts. Getting it spinning is still takes the exact same amount of time and power.
    The other problem with adding a turbo is that doing that makes zero difference to helping the car go around corners.
    It also makes zero difference to stopping the car…..
    Both those factors, corners and stopping can be helped hugely by adding lightness.

    So that’s what we did.

    IMG_20151107_145541

    We have removed the roof, the doors and changed the stock bucket seats for lightweight moulded seats.
    Sounds like a lot right?
    No.
    Sadly, it is only around 160 pounds or 72 kg’s lighter than where I started.
    I know because I have weighed the car on the local feed store grain scales.
    (BTW, FWIW, the total weight is now 1780 pounds or 897 kg’s).
    There is very little left to remove. We joked about pulling the carpet.
    The windshield is an obvious one, but doing that in California means I have to change its registration to a motorbike and wear a full face helmet every time I drive it.
    When I have to do the clutch, we have to remove the motor, at that time, we will remove the air conditioner compressor, evap radiator and hoses…. After that, I just don’t see anything left to remove….

    But, even so, the good news is that even after just dropping those ‘few’ pounds it has made a MASSIVE difference to the all round performance of the car.
    It accelerates much stronger, it can turn on a dime (I might even know that it can turn 180 degrees while staying inside a small country lane…. or I might not – Sush Matt W) and it stops beautifully (most of the time – sush Terry).

    So, all of that was a very long lead in to this article.

    http://www.cnet.com/roadshow/news/making-a-car-lighter-more-difficult-than-you-might-think/

    One might operate under the belief that making a vehicle lighter is easy — just take some stuff out, or use a new metal engineered for lightness. But there are a whole host of factors standing in the way.

    While the base body weight of a vehicle has dropped markedly over decades, desire for creature comforts and additional safety equipment has resulted in an increase in curb weight over the last 30 years, even though we’re using fewer heavy materials (like iron) than ever before.

    This isn’t even an easy topic to crack, as there are no convenient averages across the entire industry. With every car radically different than the next, despite sharing some or many similar parts, the study concludes “there is no single cost estimate (cost per pound) for lightweighting.” Thus, every company attempting to do so is taking a risk that it can’t necessarily grasp fully.

    So, it’s not as easy as Colin Chapman’s “simplify, then add lightness” quote would have us believe. In fact, adding lightness is anything but simple.

    That last sentence is the prod for this blog…. As I found out, it was a LOT of work to lighten the Smart Car. It is anything but easy to simply add lightness.



  • Wet winter inbound.

    NASA just announced that this year’s El Nino is, and I quote, too big to fail.

    Here is a sanitized news report that gives the USA view on things.

    http://laist.com/2015/10/09/el_nino_is_too_big_to_fail.php

    Bottom line, no, I am not putting the roof back on the car.
    I will probably fit the original doors back on, that will not take long to do
    but the roof is a major pain to refit, so, for now, it stays off… Note however, I reserve the right to change my mind on that one.
    Freddy and I have already talked about how we are going to manage the car’s in the rain, so we are mentally prepared.

    The thing to note is that unlike Australia, California is not set up to capture rainfall as a water source. We rely on snowpack and the resulting melt of said snow.
    So a ton of rain is only going to do a lot of damage, and nothing to help the drought. (And to top it off, the rain is too warm to fall as snow, so we are no better off next year).

    I hear that as a result of the same ocean warming, Australia is going to have a pretty warm summer.



  • Passenger side airbag sensor.

    How does the passenger side air bag sensor work?

    Give me 6 seconds of your life and I will show you.
    (Click on the image, it should start playing the mini video).

     

    Yeah, I probably need to get out more…. But if I did, where would you get your entertainment from?

    The interesting thing is the fact that the seat sensor is full of some sort of gel fluid. I guess this way no matter how or where you sit on the seat, the pressure will be measured.
    The output as an analog voltage is necessary as the airbag can fire at different strengths, so the computer needs to know how big (heavy) the person in the front seat is so it can deploy the bag at the right time and amount to decelerate the passenger.

    All very cool. Your welcome.



  • Commute to work in the Smart Car.

    For your 6 minute viewing pleasure (or otherwise), I present a pretty typical commute to work in the Smart Car.

    Bonus footage of my super messy office desk.

    I just love the way it sounds like a Formula One car when I speed up the video.
    Yeah, its a bit long, but I really wanted to show the whole thing rather than cut bits out.
    It was a pretty smooth run, did not catch every red light, but did not get all greens either (a very very rare event)…. So in that regard, it was a very typical run.



  • Just mucking about.

    Jeff got himself a glidecam. Its a weighted mount for a video camera.
    The idea is that the weight at the bottom of the mount puts the center of gravity of the whole rig at the center of the camera so it removes a lot of vibration….

    Of course, we just had to test it out….

    Don’t take it too seriously…. Clearly we weren’t!