How can you make a homemade r.c. car have low wind resistance, and not be lowered to the ground? Please help, I am doing a project and I want to make the car go faster.
Well, first you have to understand how drag works. There are three important types to consider: skin friction, form friction, and interfering friction.
Skin friction is the drag experienced when air flows over a surface, and can be minimized by using a surface with a lower coefficient of friction. The second is form friction, where the shape of the surface causes air to be pushed out of the way of the object. The most important thing about this is to limit the forward facing surface area. The smaller the outline of your vehicle, the faster it should go. Next, interfering friction is caused when pressure regions interact. For example, dragging a branch through the water will have almost as much drag as a paddle, despite having less material in the front, because the water will have to speed up as it passes between sticks. This speeding up takes more energy away from the branch, slowing it down. Limiting places where air passes between parts is a good way to fix this in your vehicle, but covering them can be just as effective.
There are some shapes that are good for limiting drag. In nature these are often reproduced by animals like fish and birds, and to a lesser extent faster mammals. This page should help with shaping.
Finally, being aware of the lift your vehicle creates is important. Keeping your lift generation in the downward direction can apply more downward force, increasing the friction on your wheels and improving acceleration. Many race cars use this, and formula one car spoilers generate so much lift, they could theoretically drive upside down. This is about these cars.