Exterior 1st Gen Splitters and Aerofoils Explained

Discussion in 'Tuning and Performance' started by nabeshin, Apr 2, 2010.

  1. nabeshin

    nabeshin New Member

    Jun 8, 2009
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    With most standard cars, the airflow over the body at speed can cause lift, making your steering go light. With splitters, some of the air that hits the front of the car goes down and impacts the splitter. Since this is attached to the car, it causes a slight downward force. With an aerofoil, it uses aircraft principles to cause lift, but the aerofoil is mounted upside down, forcing the car to the road.

    As with most fluid dynamics, the faster the fluid moves, the more pronounced these effects are. Also, as you go faster, the drag created by these downforce measures increases. So race teams have to balance speed with the need for downforce in the corners, suspension and alignment can also be used to balance the car... but I digress.

    The diagram:
    [​IMG]
     
  2. Jason Montague

    Jason Montague New Member
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    Air Foils and Splitters

    :Thumbsup:My car (08 MCS JCW [engine only not JCW body]) has no splitter and the only foil is the factory one(that 'divet' above the rear window). I have driven it to above(the speedo only goes to 150mph and the needle was buried) 150mph and the front wheels didn't seem light. So in the case of a street MCS ,do we really need splitters and foils?:cornut: Jason
     
  3. minimark

    minimark Well-Known Member

    Jun 24, 2009
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    Downforce = drag

    While going through the upper Ss at VIR with the peddle to the metal you'll want more downforce but on the street it can and will reduce MPG. I have a small splitter and lost about one MPG overall...

    Trick is, is getting the downforce you want with the least possible amount of drag.
     
  4. btwdriver

    btwdriver New Member

    May 4, 2009
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    Seeing how I know for a fact that you don't track. It's nice to know you are driving around Dallas at over 150mph.:rolleyes5:
     
  5. cct1

    cct1 Well-Known Member
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    Graham, ie "Track-Toy", is working on a track solution that hopefully we'll be able to buy ourselves.
     
  6. Jason Montague

    Jason Montague New Member
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    Not In Dallas

    :frown2: I live in Sherman,Grayson County, TX 70mi from Dallas.:Thumbsup:Jason
     
  7. beaner

    beaner New Member

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    But it's only a 20 minute drive. I call BS on 150+ mph. The MINI doesn't have enough power to overcome it's signicant drag.
     
  8. goaljnky

    goaljnky New Member

    Apr 7, 2009
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    Let us tread lightly here, folks. I am just saying.
     
  9. Jason Montague

    Jason Montague New Member
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    :Thumbsup: I agree. The friendly live and let live is why I came here.:cornut: Jason
     
  10. Ofioliti

    Ofioliti New Member

    May 9, 2009
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    Not specificaly splitters and aerofoils, but there are some pretty cool wind tunnel shots here, including the MINI:

    [​IMG]

    Compared to the other cars, you can see the turbulent zone at the boot.
     
  11. RonsMinnie

    RonsMinnie New Member
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    Cool link -- thanks
     
  12. Ofioliti

    Ofioliti New Member

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    Yeah, pretty neat. It is interesting to look at the lift and downforces (front vs back) on the different cars.

    The MINI's air drag index (0.73) doesn't seem so bad compared to some of the other cars, but of course it may not have the same power to overcome that drag.
     
  13. Jason Montague

    Jason Montague New Member
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    Drag/Topend MCS/JCW

    :Thumbsup:Thankyou very much. Now I know that the nay-sayers that would have us believe that the MCS JCW has the aerodynamics of a brick with velcro and therefore cannot achieve published top end, are incorrect. Over on Motoring File they list top speed of MCS JCW as 149mph and Mini/BMW are known to list very conservative numbers(for insurance purposes I'm told). Thanks for the info on all the cars.:cornut: Jason PS,does that 'little divot' spoiler actually do anything helpful. It appears to (in the tunnel photo) decrease rear turbulence/drag but I'm no engineer so...what do you think?
     

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