Homework: fastest way around 4 cones

Classes start this week and I’ll have a new cohort of students in my High Performance Driving class. In the first week we just hang out and meet each other, but in the second week we start talking about linear and circular performance. That is, how fast do cars go in a straight line (e.g. 1/4 mile or 0-100-0) and how fast do they go around circles. This will be their homework problem.

Given an autocross course with 4 cones, are you better off taking a large, circular path or a smaller square path? For the purposes of calculation, I have given them the following values:

• The straights are 280 ft long
• The small corners have 60 ft radii
• The large circle has a 260 ft radius

They are given a spreadsheet with various linear and circular formulae. It’s all very simple and doesn’t include gearing or aero. The inputs for the vehicle are these:

• Engine acceleration
• Brake deceleration
• Cornering grip

As part of the discussion, I ask the students to ponder how much each of the inputs matter. And even though we haven’t talked about aero, I ask them what they think will happen once it has been taken into account.

If you make a comment, please don’t provide any math or numbers. I want them to figure it out for themselves. You are welcome to predict which one is faster in qualitative terms!

5 thoughts on “Homework: fastest way around 4 cones”

1. Tiernan says:

Easy. You are “better off” taking a large circular path, predominantly sideways, doing a smoky-burnout power-slide the entire way around, and bringing the nose of your vehicle as close as possible to each cone for maximum style.

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2. Gary Smith says:

More specifically, a Miata on the circular path would beat a C8 Z06 on the shorter path.

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3. Peter says:

Horse on the square vs 18 wheeler on the circle, horse wins.

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