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  1. Join Date
    Oct 2002
    Posts
    29,354
    #21
    Quote Originally Posted by niky View Post
    http://www.airtab.com/



    Try these. They actually work, but mostly for big trucks and trailers, where drag from the trailing edge causes a huge loss of efficiency. They work by creating vortices similar to those created by Mitsubishi's "shark teeth", but instead of using it to force air to flow down to the rear spoiler for maximum downforce, they cause the turbulent air at the back of the vehicle to lift away from the body.

    One way to demonstrate this is to affix devices like this (they're not hard to make... maybe our resident mad-scientist, ghosthunter, would like to try it) on the roof and tape streamers to the rear windshield. Without the devices, turbulent air flows down across the windshield... with them, the streamers should remain calm at speeds above 60 km/h.
    No need for the resident mad scientist to make an experiment on this.

    The way that device works is it create micro vortices (mini tornadoes) which aid in the separation of the air from the sides of the truck into it's slipstream. Also, this creates a "pocket" of air behind the truck which helps reduce air drag. Without the device, the streamlined air could "cling" along the sides and around the back of the truck creating more drag.

    This is similar to the principal of a certain soviet advanced fighter jet's wing design, why it could achieve extreme maneuvers and such.

  2. Join Date
    Aug 2004
    Posts
    22,705
    #22
    I've been thinking of making a couple for myself, actually, as I regularly drive at speeds of above 60 km/h (most experimenters say there's not much in it below this speed). If it does, like some suggest, tame car motions in crosswinds, it'd help me on my reguar... uhhhmmm... high velocity tests...

    3M Command strips, with a cheap small plastic thing attached? Hmmmm...

    Ang pagbalik ng comeback...

  3. Join Date
    Oct 2002
    Posts
    14,825
    #23
    Quote Originally Posted by OTEP View Post
    Yung isang neighbor namin dito nagbebenta ng 'GAS SAVING TURBULENCE SPOILER'. hahaha. Parang yung mga nasa bubong ng Lancer EVO.

    Nakita ko nakalagay sa Pajero at sa Cefiro. Sino ba namang tuod ang bibili nun?
    May nakita na ako nito... sa Cefiro... ang swangit. :rofl01:

  4. Join Date
    Jan 2007
    Posts
    2,198
    #24
    Quote Originally Posted by OTEP View Post
    However, to get any benefit from a vortex generator. You must run the vehicle at constant speed and with sufficient airflow over the generators.

    Pretty much useless in local metro traffic conditions wherein cars rarely reach cruising speed. More like crawling speed. :lol:
    Well, at crawling speed the vortex generators and spoiler can't exactly increase your drag, so no disadvantage there. And then they start to work once you get going.

    The original topic was about wings and spoilers improving economy, and the answer is "yes", but only if your car was properly designed to make good use of the wing, like the lancer Evo 8 and 9.

  5. Join Date
    Feb 2007
    Posts
    2
    #25
    anything you put on your car that doesnt add to performance only adds to weight. thereby only increases fuel consumption. Serious studies always show that a rear spoiler only has minor "help" to handling and economy - only at speeds of 160kph. If you always drive below this speed, the rear spoiler only acts as an "extra weight" to your car and oesnt contribute to any performance at all..


    peace!

  6. Join Date
    Oct 2002
    Posts
    29,354
    #26
    Quote Originally Posted by niky View Post
    I've been thinking of making a couple for myself, actually, as I regularly drive at speeds of above 60 km/h (most experimenters say there's not much in it below this speed). If it does, like some suggest, tame car motions in crosswinds, it'd help me on my reguar... uhhhmmm... high velocity tests...

    3M Command strips, with a cheap small plastic thing attached? Hmmmm...
    You won't really find any major gain simply because a typical sedan has a very low air drag coefficient as compared to a large truck & trailer. You actually find better gains if you have your car's underside covered to reduce air drag there.

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Can rear wing/spoilers improve fuel economy