Rally racing is not just a test of driving skill, it is a test of communication, timing, and engineering judgment. On closed public or forest roads, drivers often cannot see the next corner, crest, or hazard until it is too late to react safely at racing speed. Pace notes solve this problem by turning the road ahead into a coded stream of information read aloud by the co-driver.
The system lets the driver commit to speed, braking, and line choice before the road is visible.
Key Facts
- Pace notes describe the road ahead using distance, direction, corner severity, road shape, and hazards.
- A common corner scale uses 1 for very slow or tight turns and 6 for fast or nearly flat turns, but teams may use different systems.
- Example sequence: 100, R5 over crest, 50, L3 tightens, don't cut, into hairpin right.
- Stopping distance depends strongly on speed: d = v^2 / (2μg) for ideal braking on level ground.
- Reaction distance is d = vt, so a 0.5 s delay at 30 m/s adds 15 m before any braking begins.
- During recce, the driver and co-driver travel the stage at controlled speed to create, check, and refine the pace notes before competition.
Vocabulary
- Pace notes
- Pace notes are a coded written description of a rally stage that tells the driver what is coming next.
- Co-driver
- The co-driver is the navigator who reads pace notes at the correct time and helps manage timing, route, and stage information.
- Recce
- Recce is the pre-event reconnaissance drive where the crew studies the stage and creates or checks their pace notes.
- Crest
- A crest is a rise in the road that can hide the road beyond it or reduce tire contact if the car becomes light.
- Don't cut
- Don't cut means the driver should avoid placing wheels inside the corner because of a hazard such as a rock, ditch, rut, or barrier.
Common Mistakes to Avoid
- Reading the notes too late is wrong because the driver needs time to brake, position the car, and set up for the next feature before it is visible.
- Treating every number system as universal is wrong because one team's 5 or 6 corner may not match another team's scale or driving style.
- Ignoring distance calls is wrong because the gap between features controls rhythm, speed choice, and whether the driver can fully accelerate.
- Thinking the co-driver only gives directions is wrong because pace notes also include grip changes, crests, jumps, hazards, surface changes, and warnings about line choice.
Practice Questions
- 1 A car is traveling at 27 m/s and the co-driver gives a braking call 2.0 s before the corner. How far does the car travel during that time before braking begins if the driver waits the full 2.0 s?
- 2 On gravel, assume μ = 0.60 and g = 9.8 m/s^2. Using d = v^2 / (2μg), estimate the ideal braking distance from 25 m/s to rest on level ground.
- 3 A pace note says 80, crest into L2 tightens, don't cut. Explain what information each part gives the driver and why trust between driver and co-driver is essential on a blind road.