This adjuster cylinder helps the driver adjust to track conditions so that when the track
In the first example of our hand in the wind, we were able to adjust the amount of force that we could feel by changing the position of our hand in the air stream. We adjusted the drag and lift with one simple movement. We can also affect our race car's ability to move through the air and reduce the amount of power required to move the car down the track by adjusting the way the air interacts with the car. If we reduce the drag, the power that was previously used to overcome the drag can be used to accelerate the car.
One of the easiest ways to reduce the power-robbing effects the air has on our racing vehicles is to reduce the frontal area. This can be accomplished in a number of ways. The simplest way would be to make the car smaller. This is not always possible due to rules and the use of templates by the technical community to ensure the cars are all the same. If you can, make the car lower while still meeting the letter of the rules-you need to do it! Lower the roof, and lower the car to the track within the rules and the boundaries required to keep the car from hitting the track.
If the rules say the car has to be 4 inches off the ground, that is where you put it-not 5 or 4 1/2, but 4. While this may seem to be a simplistic solution, this activity can significantly reduce the frontal area of your car. It will reduce the size of the hole in the air that the car will be required to penetrate as it moves down the track. The larger the hole, the greater the horsepower required to move the car. As a direct result, you will have less horsepower in surplus to accelerate the car.
This prototype has a splitter piece that the air flowing under the car must flow past. It
You also want to keep the air from under the car. For the most part, you will not find ground effects cars at the local short track. The point is to keep the air on the outside of the car. This includes the air that will go through the radiator. Get it in and then get it out. If your rules allow it, you should try to duct the air back to the outside of the car, not under it. I realize this is difficult to accomplish, but there is an advantage gained by doing this. Not long ago, I saw some Sprint Cars that had special radiators off to one side. The ducting away from the radiators dumped the air out along the side of the hood, and the air intake was on the opposite side of the car. Air in, air out-quite a clever bit of engineering!
Every surface that interacts with air should be as smooth as possible. All body joints need to be smooth, with no edges or overlapping seams facing the airflow. Look at your car and see what areas you might improve from an aero perspective. While many would like to think of this as rocket science, at these lower speeds it is more common sense than science. As the speeds increase, the need for greater levels of science is required.
At short-track speeds (below 100 mph), it is more imperative to make sure you are not giving anything away due to overlooking an area or poor preparation. You need to look at large spoilers, air dams, and air fences as devices that may not be necessary at low speeds. Rear spoilers greatly deprive a race car of power. If you don't need one, you may consider removing that 4- or 5-inch spoiler. At the very least, do some on-track testing to determine if the spoiler makes a difference. The amount of downforce a spoiler makes may be insignificant when balanced against the potential drag.
The control arms on this prototype are shaped to be very aero efficient. While this shape
From your perspective, we need to make sure we are exploiting the rules to our full advantage. I am not suggesting cheating. We need to review the rules and make sure we are doing every legal thing to make the air around us an ally. If you have tubing exposed, place some shaped foam on the downstream side to make air flow around the tube in a less turbulent way.
Are body panels mounted with hex-head bolts exposed to the air stream? Why not use a counter-sunk screw or a flush-mounted 1/4-turn fastener to secure a body panel? Cleaning up the surface of the body can and will make a big difference, not to mention it looks more professional to the other railbirds in the pits.
Look at the wheel cutouts. Are they too big? Cutouts that are too big are just big scoops sucking in air. Make sure the wheelwells are not larger than they need to be to conform to the rules, and then make sure they are not so small that they interfere with the tire through its suspension travel and the steering function. This is just good car preparation.
It is easier to make the wheel openings larger. If you have made the fender opening too big, it may be time to replace the fender and start over or replace the metal you have cut off. If your tires are sticking out past the edge of the fender, you will want to do everything possible to cover that tire. Remember that frontal area we are so concerned about? You have fenders, so use them to your advantage.
As stated, at the lower speeds seen at the short-track level, this is more common sense than rocket science. Preparation followed by execution will help you be the guy smiling after the race with the giant check.