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7 G's in a Hot Wheels Loop — Parallax Forums

7 G's in a Hot Wheels Loop

ercoerco Posts: 20,259
edited 2012-07-09 17:51 in General Discussion
We scaled up one of my Hot Wheels sets and had fun at the X Games in Los Angeles today. Fun stuff. Too bad my Corvair wasn't road ready. :)
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Comments

  • PublisonPublison Posts: 12,366
    edited 2012-06-30 15:23
    erco wrote: »
    We scaled up one of my Hot Wheels sets and had fun at the X Games in Los Angeles today. Fun stuff. Too bad my Corvair wasn't road ready. :)

    No way dude!

    Does it make margaritas at the end?
  • ercoerco Posts: 20,259
    edited 2012-06-30 15:29
    No, but there were plenty of margaritas flowing last night at the Conga Room! :)
  • mindrobotsmindrobots Posts: 6,506
    edited 2012-06-30 15:29
    The difference between men and boys is the price of their toys!

    This is too cool!!
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-06-30 15:51
    Thank you erco!

    That was awesome!

    Do they hit 7Gs within the first quarter of the loop?
  • ercoerco Posts: 20,259
    edited 2012-06-30 16:02
    Good call, my young Padawan! Max Gs at the bottom entering and exiting the loop, minimum at the top. Technically, they could be at zero G at the top of the loop. Bad time to chicken out and apply the brakes. :)
  • Martin_HMartin_H Posts: 4,051
    edited 2012-06-30 17:02
    That was awesome!
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-06-30 17:10
    Wow! Impressive! A question, though: I can understand why the entry speed has to be at least X, but why must it be less than Y (aside from bursting through the track at the bottom)?

    -Phil
  • hover1hover1 Posts: 1,929
    edited 2012-06-30 17:19
    Is that track still set up? I know a guy that would like to try a hovercr...... never mind. :)
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2012-06-30 17:30
    erco wrote: »
    Too bad my Corvair wasn't road ready.

    You mean road worthy! :lol:

    Do they ever really have a true zero-g moment at the top of the loop? Seems an unnecessary risk to drive slowly enough to have just 1g by centrifugal forces to counter the 1g of gravity.

    -- Gordon
  • W9GFOW9GFO Posts: 4,010
    edited 2012-06-30 17:59
    Seven Gs? Has anyone done the math to support this? We know the speed, what is the diameter of the loops?
  • Martin_HMartin_H Posts: 4,051
    edited 2012-06-30 18:41
    Phil Pilgrim (PhiPi) wrote: »
    Wow! Impressive! A question, though: I can understand why the entry speed has to be at least X, but why must it be less than Y (aside from bursting through the track at the bottom)?

    A wild guess, but if they go too fast they might pull too many G's or for too long and black out. 6 G's is supposed to be risky, so above 7 would definitely be a risk.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-06-30 18:43
    Martin,

    If I recall correctly from the video, X and Y were too close together for that to be the reason.

    -Phil
  • W9GFOW9GFO Posts: 4,010
    edited 2012-06-30 18:57
    I would guess that the reason for limiting the speed below a certain value is for the protection of the structure.

    Also, those cars appeared to either have very, very stiff or no suspension at all.
  • W9GFOW9GFO Posts: 4,010
    edited 2012-06-30 19:04
    My rough calculations indicate an average of about 4 Gs with a peak (.5 seconds) of about 9 Gs.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-06-30 19:04
    'Not buyin' it. The video said the entry speed has to be between 48 and 52mph. If the structure isn't sound at 53 mph, it won't be at 52 mph, either. There has to be another reason.

    -Phil
  • W9GFOW9GFO Posts: 4,010
    edited 2012-06-30 19:11
    Could be that the announcers were playing it up a bit?

    They have their notes that say entry is between 48 and 52mph, then they say to the audience that it has to be between 48 and 52mph.
  • Dave HeinDave Hein Posts: 6,347
    edited 2012-06-30 20:21
    The max speed may have more to do with the ramp after they exit the loop. If they go too fast they'll have a rougher landing on the other side of the ramp. There also isn't much room for stopping at the end of the track.

    EDIT: I calculated that they had a centripetal acceleration of about 1.7 Gs at the top of the loop. Subtracting 1G for earth's gravity leaves about 0.7 G pushing against the top of the loop.
  • skylightskylight Posts: 1,915
    edited 2012-07-01 07:57
    Saw it on Sky News this morning, impressive!
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-07-01 08:07
    W9GFO wrote: »
    My rough calculations indicate an average of about 4 Gs with a peak (.5 seconds) of about 9 Gs.

    I don't see why the acceleration would change more than 2g (from 7g to 5g).

    Assuming 7g (6g from the loop itself) and 52mph are correct, I get a loop with a diameter of 60.6 ft (which seems pretty close to size of the loop).

    Then, assuming they wanted to maintain a solid g agaist the top of the loop (instead of 5), if I compute the speed needed hold the cars in place I get 30 mph.

    All I can figure is the speed stated is required to safely get over the jump.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2012-07-01 10:28
    What worries me is that reality is beginning to mimic childhood. It wouldn't be so bad except that childhood in the past 40-50 years has gotten to be more and more based on the fantastic.

    In another 50 years, will freeways have loops and jumps? Was I just born too soon for those?

    And is it just me, or did the following car just barely make the jump?
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2012-07-01 10:33
    BTW, if you go to fast the suspension bottoms out and you get a very hard jolt that would effectively bounce you off the road bed. That would be a great opportunity to loose control.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-07-01 10:59
    According to this article, the loop is 66 ft in diameter.

    At 52 mph, the g-force should varry between 6.5g at the bottoms of the loop and 4.5g at the top of the loop.

    I don't understand why they need to maintain such a fast speed. 46 mph would give them a full g of force against the track when they are upside down. At 46 mph, the drivers would only have to handle 3g's.

    Edit: If they were willing to be weight-less at the top of the loop, they'd only need to be going 32.5 mph (though I agree this would be too dangerous).
  • ercoerco Posts: 20,259
    edited 2012-07-01 11:20
    Lots of smart people with all the right answers here! Any speed above a minimum would keep the car in the loop. Max speed was limited for G-force on the drivers & structure, and tuned for jump length & stopping distance. AFAIK, the tires are the only "suspension" in these cars. The 7G force would quickly bottom out any suspension travel, as would landing on the jump ramp. And yes Loopy, Tanner in car 2 just barely cleared the landing ramp.

    And let's hope this paves the way for our freeways to have loops in the near future. That will reinforce the minimum speed requirement for all the lookie-loos doing 35 mph in the fast lane!
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-07-01 11:24
    erco wrote: »
    Tanner in car 2 just barely cleared the landing ramp.

    It looks like he hit the edge of the far side of the jump with his tires. It's pretty amazing he didn't have a blow out.

    That was an amazing loop and jump.
  • skylightskylight Posts: 1,915
    edited 2012-07-01 11:47
    erco wrote: »
    And let's hope this paves the way for our freeways to have loops in the near future. That will reinforce the minimum speed requirement for all the lookie-loos doing 35 mph in the fast lane!

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  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-07-01 13:00
    erco wrote:
    And let's hope this paves the way for our freeways to have loops in the near future. That will reinforce the minimum speed requirement for all the lookie-loos doing 35 mph in the fast lane!
    I'll second that! I'd like to see several of these on Bainbridge Island to keep the local yokels from holding up people who are trying to make the ferry to Seattle.

    -Phil
  • PublisonPublison Posts: 12,366
    edited 2012-07-01 17:10
    Phil Pilgrim (PhiPi) wrote: »
    I'll second that! I'd like to see several of these on Bainbridge Island to keep the local yokels from holding up people who are trying to make the ferry to Seattle.

    -Phil

    And have that good jump just in case you are "REALLY" late for the ferry. :)

    Can the Mercedes do that? Sure it can :)

    Jim
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-07-01 21:20
    Publison wrote:
    Can the Mercedes do that?
    Hmmm, probably not. Maybe I should just get a snow plow attachment for it and loud klaxon horn like fire trucks use.

    -Phil
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2012-07-02 00:44
    Could it just be that the promoters are making a bit more drama than there is?

    I suspect the critical speed is mostly dictated by making that jump. Slower may do a beautiful loop, but with a rather bad ending.
  • davejamesdavejames Posts: 4,047
    edited 2012-07-02 08:13
    ...the videos have been removed.

    Why for?
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