by slothead » Sat Jul 20, 2019 8:56 pm
Harry - you're going to need more popcorn for this, my apologies.
A slot car wing is not going to have enough surface area or speed to generate any meaningful down force if it's realistically sized. Also, functional wings have a precise shape. Wright Bros discovered a wing has to have a particular shape to generate lift (or conversely down force). An airfoil's shape creates a mismatch in the speed of the air going over and under it, which creates more air pressure on one side than the other. A plane's wing creates lower pressure on top and higher pressure below, resulting in lift. (Same principle as a curve ball - it's spin creates more air pressure on one side which makes it arc.)
The amount of lift or down force is proportional to the surface area of the wing, it's shape, orientation, and speed of the air passing over it. At slow speeds there is no lift and a plane stalls and descends to earth with often catastrophic results. Anyone who flew model airplanes has learned this the hard way. If anyone here flew model rockets you know fins do nothing to stabilize the rocket till it gets up to speed.
Height of the wing is only a factor because it gets it out of the turbulent air flowing over the car and into clean air. But, at slow speeds air is not dense enough to make any meaningful difference.
How to test? Mount the wing in the configuration where you suspect it creates down force and time trial the car. Then invert it's orientation so that now it should create the same amount of lift and time trial again. Any effect would be doubled when the down force condition is compared to the lift condition, so if there is an effect it should be apparent. I suspect in a fair comparison there would be no advantage or disadvantage across conditions.
If anyone is warped enough to go down nerd alley with me to check this out we could build a scale wind tunnel to do it. Put the car on a digital scale in the wind tunnel and see if its relative weight changes with air passing over it at realistic speeds.
Harry - you can lighten up on the popcorn now. Mumbo-jumbo terminated.