what are these?

Discussion in 'Hangar Talk' started by GeorgeC, Jan 5, 2016.

  1. SoonerAviator

    SoonerAviator En-Route

    Joined:
    Jul 21, 2014
    Messages:
    3,527
    Location:
    Broken Arrow, OK
    Display Name:

    Display name:
    SoonerAviator
    Again, they're almost purely for aesthetics. There may be some fraction of an mpg gained from it due to some reduction in drag, but I'm willing to bet it's minimal in effect especially at city speeds. I'm sure many of the small design items don't add much in efficiency gains by themselves, but may be a "sum of the parts" advantage.

    If you're driving the semi trucks with enormous side-profiles and lots of wind turbulence, the side skirts and rear-fairings make a noticeable difference in fuel efficiency. They are traveling at highway speeds 90% of the time, so they reap a lot on the efficiency gains. You don't see those trailer additions on trucks used for local transport because there's not much advantage to them at 45mph.
     
  2. wrbix

    wrbix Cleared for Takeoff

    Joined:
    Jul 25, 2013
    Messages:
    1,479
    Display Name:

    Display name:
    Pilot Lite
    As pictured, TTRS.... APR Stage One... 410 HP, 447 ft-lb torque... 0-60 much quicker than I can shift...top speed limited electronically - never been there.


    No, I don't think Audi would put one on an A4.
     
  3. Pilawt

    Pilawt Final Approach

    Joined:
    Sep 19, 2005
    Messages:
    6,433
    Display Name:

    Display name:
    Pilawt
    Those late '50s cars might not have been aerodynamically efficient, but it sure looks like they had ample lateral stability ...

    [​IMG]

    :D
     
  4. SoonerAviator

    SoonerAviator En-Route

    Joined:
    Jul 21, 2014
    Messages:
    3,527
    Location:
    Broken Arrow, OK
    Display Name:

    Display name:
    SoonerAviator
    Also, if I remember correctly, didn't the early TT have some issues early on with the car wanting to flip or get really loose at high speeds (100+)? I thought I recall the spoiler being added at that point to help eliminate some of that tendency. It was due to the design of the TT that was causing the rear end to get light.

    The Corvette never really came with a spoiler, aside from a few "lip spoilers" that were pretty minimal in size because the body design was sort of a wing in itself. The spoilers/wings that are truly functional aren't added until the -R series 'Vettes are included in the discussion, and those aren't for street use. Those are much more intrusive and are adjustable for different tracks/speeds as well.

    Nowadays, the sports car designers do as much work under the body to hold the car down as they do on top.
     
  5. wrbix

    wrbix Cleared for Takeoff

    Joined:
    Jul 25, 2013
    Messages:
    1,479
    Display Name:

    Display name:
    Pilot Lite
    :rofl::rofl:well played.
     
  6. rbridges

    rbridges En-Route

    Joined:
    Nov 9, 2012
    Messages:
    2,577
    Location:
    Warner Robins, GA
    Display Name:

    Display name:
    rbridges
    I don't think you're officially a douche until you put the oversize exhaust on it i.e. fart can.
     
  7. X3 Skier

    X3 Skier En-Route

    Joined:
    Jul 3, 2011
    Messages:
    2,820
    Location:
    I19 & SBS
    Display Name:

    Display name:
    Geezer
    Agreed!

    One of the world's really bad ideas.:D

    Cheers
     
  8. GeorgeC

    GeorgeC Pattern Altitude

    Joined:
    Dec 5, 2010
    Messages:
    2,307
    Display Name:

    Display name:
    GeorgeC
    It was your earlier post that reminded me to pick up that spoiler for my car. I observed about +1mpg (used to have to work to get high 30.x, now high 31.x comes easily), but I attribute that mostly to the four new and improved tires I put on.
     
  9. silver-eagle

    silver-eagle En-Route

    Joined:
    Mar 11, 2005
    Messages:
    4,649
    Location:
    Massachusetts
    Display Name:

    Display name:
    ~John
    That's to cut down on people drafting off his trailer.
     
  10. gerbs

    gerbs Filing Flight Plan

    Joined:
    May 5, 2014
    Messages:
    17
    Location:
    Santa Monica, CA
    Display Name:

    Display name:
    gerbs
    Just another terrible trend new cars are following. It started with the Prius imo and now leaking into other designs.
     
  11. Checkout_my_Six

    Checkout_my_Six Final Approach

    Joined:
    Mar 4, 2007
    Messages:
    8,316
    Location:
    Maryland
    Display Name:

    Display name:
    Check_my_Six
    to put this in simple terms.....dynamic pressure (force over an area) is pd = 1/2 ρ v2 ......

    varies proportionally with density and "velocity" squared.

    So, vehicles moving in city traffic.....ain't making much pressure. :rolleyes2:
     
  12. silver-eagle

    silver-eagle En-Route

    Joined:
    Mar 11, 2005
    Messages:
    4,649
    Location:
    Massachusetts
    Display Name:

    Display name:
    ~John
    Read "All Corvettes are Red". In it, you'll see where the design team struggled to remove mean ounces to reduce the overall weight to gain but a fraction of mpg. It all matters and depends on what they are trying to accomplish.
     
  13. SoonerAviator

    SoonerAviator En-Route

    Joined:
    Jul 21, 2014
    Messages:
    3,527
    Location:
    Broken Arrow, OK
    Display Name:

    Display name:
    SoonerAviator
    Agreed, no doubt that engineering departments can be exhaustive in certain areas depending on the end goal. I just don't know how much the rear spoiler or faux vents really attribute to drag reduction on many vehicles. There are plenty of examples where trunk spoilers exist on the "sport" models, but don't exist on the base models (think '99 Pontiac Grand Prix). I'm willing to bet that most are non-functional other than for aesthetics regarding any performance gain (whether that's traction or fuel mileage).

    When it comes to items like active-shutter grills, undercarriage body panels, etc, there's no doubt that those small bits were added to eek out those tenths of an mpg. :yesnod: