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Reducing drag coefficient

Discussion in 'Roadster' started by asgard, Apr 28, 2016.

  1. asgard

    asgard Member

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    If Wikipedia is accurate, the Roadster has a Cd (drag coefficient) of 0.35 whereas the Model S is 0.24 and the Model 3 may be even lower. I am wondering if there are low-hanging fruit to be had on the Roadster and that can be done aftermarket?
     
  2. wiztecy

    wiztecy Active Member

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    Santa Cruz, California, United States
    #2 wiztecy, Apr 28, 2016
    Last edited: Apr 28, 2016
    Yes, its been discussed before and there should be a few threads on it.

    But mirrors are red hot on the drag if you see the heat map on it. Also having a proper 5 element rear pan/diffuser that comes out 3 inches off the rear so all that sticky air doesn't grab the bumpers is another one. Filling in the gaps where the bottom aluminum pan doesn't cover the lower suspension / control arms is another one.

    A person over in Europe came up and had fabricated a rear diffuser that's totally functional in reducing drag, would love to get the specs / diagrams on that and have one built up out of carbon fiber.

    F1 inspired parts anyone?
    Hi All from Oxford, England, UK - F1 inspired parts anyone?

    [​IMG]
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    Has anyone played with rear diffuser fins - like the Elise

    And then PV4EV's mods:

    Roadster 3.0
     
  3. asgard

    asgard Member

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    I'd be up for discussing a group-buy with Dietsch if there is a rear diffuser design that has been simulated.
     
  4. ViperDoc

    ViperDoc Roadster 1305

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    I seem to recall a thread here in which a guy in the UK had done a whole series of mods to his Roadster after doing very detailed testing of drag. This included changing the mirror mounts. He claimed he had a range of like 300 miles at normal speeds (eg, not doing 30 mph). He also commented that when he took it to the local SC, he removed lots of the mods but they still took notes on the things he didn't take off.
     
  5. wiztecy

    wiztecy Active Member

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    #5 wiztecy, Apr 28, 2016
    Last edited: Apr 28, 2016
    I believe that was PV4EV's Blue Roadster, I supplied the link above but here it is again. He was able to get 300 miles driving highway speeds running the original Roadster battery.

    Also the front splitter, especially on the 1.5, could be drastically improved to redirect airflow properly down and around the Roadster than what the stock one does now.

    Lastly, adding side sills like the ones below would help to direct and reduce the airflow properly around the sides of the Roadster.
    Racesills - Increased Downforce and Drag Reductions?

    [​IMG]

    Here's the heatmap of the Roadster regarding drag:
    [​IMG]


    Adding a fin to the front side of the nose as in this pic should help with that red hot spot on the left front nose, right in front of the wheel plus add more down-force to the front wheels at higher speeds:

    [​IMG]

    Lastly, PV4EV's pics:
    Roadster 3.0

    [​IMG]

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    [​IMG]
    [​IMG]
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    [​IMG]
     

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