You don’t need another countdown to Daytona, but perhaps a little more information about Daytona will help you appreciate it that much more when it does come. A large part of that is the banking.
Why Daytona is Fast
Daytona International Speedway gets its speed from two aspects of its configuration:
- Large-radius turns
- High banking
Banking helps a racecar turn. On a flat track, the tires have to do all the work. On a banked track, part of the force the track exerts on the car is to the left, which adds to the turning force of the tires.
You experience this same effect when you exit a highway. Banking (not quite as much as on a race track) helps fit the off ramp into a smaller space.
The banking is so effective that you could take a corner at Daytona at 140 mph even if the track were completely covered in ice. Of course, you would have to get the car moving first…
The Trigonometry of Daytona Banking
Most tracks will give you the banking and the track width. From there, it’s just a little trig to figure out the rest.
The sine of an angle is just the ratio of the side opposite the angle to the track surface width (aka: the hypotenuse). The cosine is the ratio of the side next to the angle to the track surface width.
Daytona has a banking of 31 degrees in the corners and a track width of 40 feet. Using opposite side = track width * sin(31), we find that the rise is about 20 feet. The run (adjacent side = track width * cos(31)) is about 34 feet.
In other words, the banking is such that, for every foot you go over, you go up a little more than six inches.
For comparison, the ‘banking’ of a typical stairway is between 30 and 35 degrees.
And just to give you something to compare it to, here’s me standing on the surface at Texas Motor Speedway, which is only 24 degrees.
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What is the minimum speed on the track at Daytona (during yellow flags) or if black flagged stopped?
Hi Robert: NASCAR doesn’t have a minimum speed under yellow flags. Drivers must stay behind the pace car, who generally sets the speed.
This is actually not true. Different tracks have different pacing speeds. For example, Watkins Glen has a pace speed of 45MPH, Bristol has a pace speed of 35MPH, and Daytona has a pace speed of 70MPH. And while there is no rule about a minimum MPH, there is a minimum lap time requirement.
The pace car speed is a maximum speed, not a minimum one. The rules state that you lose your place in the field if you fail to keep up with the pace car, but there is no requirement that you sustain a minimum speed. If you want to trundle around the back of the field much slower, you can do that, as long as the pace car doesn’t catch up to you.
The minimum lap time requirement only applies to green-flag laps, and only if a car has been in an accident. The minimum speed is the speed a car must meet after being on the dvp clock to be allowed to continue. NASCAR rarely black flags cars for being too slow on track unless there is a problem that poses a threat to other competitors.
Because distance is speed times time, any speed requirement is the same as a lap time requirement. I wrote about that here: https://buildingspeed.org/2017/04/21/are-posted-lap-speeds-really-accurate/