hate these ads?, log in or register to hide them
Page 82 of 82 FirstFirst ... 327279808182
Results 1,621 to 1,629 of 1629

Thread: The Dumb Science Questions - Pro Science Answers Megathread

  1. #1621
    Super Moderator Global Moderator QuackBot's Avatar
    Join Date
    March 7, 2012
    Posts
    7,784
    Quote Originally Posted by Zibu View Post
    Now combine that drive by wire hack, with

    (RC F16's)
    and you can start talking about fun and damage you could cause...
    Now i'm one-shotting turrets, fun. And what kind of indiscretion dit lark do?

  2. #1622
    theBlind's Avatar
    Join Date
    April 9, 2011
    Posts
    1,107
    Quote Originally Posted by QuackBot View Post
    Quote Originally Posted by Zibu View Post
    Now combine that drive by wire hack, with

    (RC F16's)
    and you can start talking about fun and damage you could cause...
    Now i'm one-shotting turrets, fun. And what kind of indiscretion dit lark do?
    Can we stop discussing drones with quackerz around? It might give him ideas and he's already asking for excuses...
    Tanks: theBlind[URBAD] (in my heart there will always be a place for [FAIL])
    Planetside2: [UBAD]theAngelic

  3. #1623
    dpidcoe's Avatar
    Join Date
    June 29, 2011
    Location
    San diego
    Posts
    4,907
    Quote Originally Posted by Cool09 View Post
    Quote Originally Posted by Frug View Post
    Quote Originally Posted by Cool09 View Post

    Why? Incase someone enters your car, and plugs into your OBD port with a laptop?
    Are you actually this dense?
    No really... how is someone going to "hack" your ECU as the forbes article is so paranoid about.
    http://www.amazon.com/Version-Blueto.../dp/B008UR7J6I
    i heard you're ideas and their definately good

  4. #1624

    Join Date
    April 11, 2011
    Posts
    958
    Ok these look pretty cool. My mazda is starting to feel a little sluggish, will one of these help me figure out what is starting to give?

    http://www.amazon.com/BAFX-Products-...productDetails
    I'm sure it's frustrating to be sperging about how someone said "no, not doing that yet" - but we've had 7 years to learn to pace ourselves after killing a block. And I dare say -- we've gotten quite good at it.

    Sorry if it doesn't suit the armchair generals who have never committed to anything for more than 2 months, but by now we've learned that we really don't give a shit about what you think v0v.

  5. #1625

    Join Date
    April 14, 2011
    Posts
    3,906
    Quote Originally Posted by LoKiPP View Post
    Ok these look pretty cool. My mazda is starting to feel a little sluggish, will one of these help me figure out what is starting to give?

    http://www.amazon.com/BAFX-Products-...productDetails
    Personally I have http://www.launchtechusa.com/assets/.../products.html I have an older CReader with just a little black/green lcd screen. Works fine with every vehicle I've tried it with. Also one thing to keep in mind is that these only read out OBD fault codes from the ECU, some cars have additional body computers that you need a proprietary reader & software to access, but thats for shit well beyond reading engine check light faults.


  6. #1626
    Smegs's Avatar
    Join Date
    April 2, 2012
    Posts
    385
    Quote Originally Posted by LoKiPP View Post
    Ok these look pretty cool. My mazda is starting to feel a little sluggish, will one of these help me figure out what is starting to give?

    http://www.amazon.com/BAFX-Products-...productDetails
    You need to use that in conjunction with an APP on your phone or Laptop (Torque Pro is highly recommended) and it will show you the full list of ODB2 fault codes if any are within your cars ECU, but on top of that you will also be able to view quite a lot more information beyond the codes as well. I would highly suggest looking at the Fuel trims of your engine as a first place to look if you feel that the engine has lost quite a few ponies (look on-line for what your correct fuel trims should be). Second would be the output from the O2 sensors, which will cause incorrect fueling and poor burn of the fuel within the cylinders.

    One thing these unit do not do, is tell you exactly what the problem is. It will only tell you what the ECU regards as a fault.

    For instance, if your ECU coder is saying a misfire on cylinders 1 and 3, it could be a faulty O2 sensor causing the cylinders to run rich or lean, causing the misfire....


    edit BTW what type of Mazda do you have. I have an awful lot of experience with MK1 and Mk2 MX5's ... and also the Mazda Diesel engine used by Ford
    Last edited by Smegs; October 23 2013 at 05:28:47 PM.
    Shitting up eve for .... well, longer than most of you scumbags.

  7. #1627
    dpidcoe's Avatar
    Join Date
    June 29, 2011
    Location
    San diego
    Posts
    4,907
    Quote Originally Posted by LoKiPP View Post
    Ok these look pretty cool. My mazda is starting to feel a little sluggish, will one of these help me figure out what is starting to give?

    http://www.amazon.com/BAFX-Products-...productDetails
    That one you linked is the exact one I have. It interfaces with the torque phone app flawlessly, and even lets you reset the error codes.

    If it's a miata that you have (especially if it's an older one), I'd recommend looking at the MAF first. The sensor can get dirty and screw the rest of the system up. Or someone could have done the worlds worst kludge job on it. This is what I found in mine when I took it apart:
      Spoiler:

    Looks normal-ish right?


    uh...


    seriously wtf??


    previous owner had cut up this tube to take the place of a $15 part:



    More on topic of the thread, could someone explain wtf is going on here with the intermediate spin:
    i heard you're ideas and their definately good

  8. #1628
    kyrieee's Avatar
    Join Date
    April 9, 2011
    Location
    derp
    Posts
    2,337
    It's a property of rotating rigid bodies.
    Rotation around the principal axis with the highest or the lowest moment of inertia will be stable, but rotation around the third axis (which has neither the largest or the smallest moment of inertia) will be unstable. You can try it with any object, preferably something where you can easily identify the axis, like a deck of cards. Let's call the smallest face of the box with the cards in it 'a', the intermediate one 'b' and the largest one 'c'. If you try throwing the box so that it rotates around the axis going through 'a' or 'c' you'll see that it rotates normally, but if you try to rotate it around the 'b' axis it'll spin around like crazy. Why? Math. Maybe someone can provide you with a good explanation, but it's not a very intuitive result IMO. In principle I think you can make something spin around the intermediate axis, but if it's even slightly off it will start to wobble.

    If you want to get a bit more technical, the magnitude of the angular momentum vector & the total kinetic energy has to be preserved in the absence of external forces. For rotation close to the 'a' and 'c' axis this will result in precession around those axis, but for the 'b' axis there's no similarly stable way to conserve the momentum:

    The ellipsoid corresponds to the three moments of inertia (which corresponds to the energy conservation constraint), so the 'a' axis is the longest and 'c' the shortest. The curves in the picture are the intersections between an ellipsoid and a sphere. The sphere obviously comes from the condition for conservation of angular momentum. So the curves are just the points which satisfy both conditions.

    edit: made a correction
    edit2: to be a bit more clear, the ellipsoid itself is a representation of how fast the object has to spin around a given axis to have a given rotational energy. So because 'a' is the smallest moment of inertia it needs to spin the fastest around 'a' of all the other axis to have a given energy, that's why the ellipse is longest there. The curves represent points which have the same energy AND the same angular momentum.
    Last edited by kyrieee; October 25 2013 at 05:59:18 PM.

  9. #1629

    Join Date
    April 11, 2011
    Posts
    2,293
    A mathematical treatment of the problem

    http://www.stanford.edu/class/me331b...ofInertLab.pdf

    I think it is pretty clear.

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •