How to Calculate the Track Length for a Slot Car

Slot car lanes differ as they round turns.

The measure of a slot car enthusiast's skill is often measured in speed. Hours of effort go into designing and creating the fastest cars. In order to measure the speed of a slot car, one has to either have a radar speed gun or time how long it takes for the car to complete a track of known length. Because of the turns and twists of many slot car tracks, it can be difficult to know exactly how long a particular track is. Exacerbating this problem is the fact that a car traveling on the outside of a turn travels farther than one on the inside. This problem is easily solved using a little math or a piece of string.

Things You'll Need

• Tape measure
• Paper
• Pen
• String
• Scissors
• Adhesive tape

Instructions

Mathematical Calculation

1. 

   Measure the straight pieces of track.

   Measure all the straight pieces of track in inches with the tape measure and record their lengths. Add these lengths together to get the total straight length of the rack.

2. Count the number of 1/8th turns on the track. On most commercially available tracks, each length of a turn is 1/8th of a complete turn. This means a 180 degree turn, the kind that turn the slot cars fully around back towards the way they came, is made of four 1/8th turns.

3. Note which lane is on the inside and which is on the outside of each 1/8th turning piece of track. The length for the outer lane will be longer than the inside lane.

4. Measure the distance from the inner edge of the track to the outer edge of the track. This is the track radius.

5. Use the table located in the References section to determine the length of inner and outer lanes depending on the radius on the turn.

6. Add up these lengths to the total straight length of the track to determine the total length of each of the lanes on your track.

String Measurement Method

1. Tape one end of the string at the beginning of the lane you wish to measure.

2. Run the string along the length of the lane, taping as you go. Do not leave any slack in the string and be sure to follow the lane around all turns.

3. Cut the string when you get to the end of the track.

4. Measure this string to get the total length of the lane you measured.

References

• HO Slot Car Racing: Tracks
• Slot Car Academy: Track Selection for Beginners