SPEED RALLY
Fastest wins.Performance is primarily about completing a stage in the shortest time.
EZ RALLY KNOWLEDGE
REGULARITY RALLY
TIMING, EXPLAINED.
Regularity rallying is about precision rather than outright speed — but the way precision is measured is not the same at every event. This guide explains the big picture first, then the PC, SPC and CO terminology used by EZ Rally Timer.
Important: terminology, timing methods, penalties and permitted equipment vary by country and event. The organizer’s current regulations, roadbook, briefing and official timing always take precedence.
01 — THE BIG PICTURE
WHAT IS A
REGULARITY RALLY?
A regularity rally is not a conventional speed rally. The objective is normally to follow a prescribed route while matching target times or prescribed average speeds as accurately and consistently as possible.
In FIA historic regularity rallying, for example, a regularity section tests a crew’s ability to maintain a precise average speed over a defined route. A section can include a start control, intermediate timing controls and a finish. Other events use different formats: some focus on maintaining an average speed across a section, while others score the accuracy with which a car reaches or crosses a particular timing point.
REGULARITY
Precision wins.Performance is about matching the organizer’s prescribed timing or average-speed requirement.
This distinction is consistent with FIA’s description of historic regularity rallying and with widely used regularity-rally terminology.
02 — ONE DISCIPLINE, DIFFERENT FORMATS
“REGULARITY” DOES NOT MEAN
ONE UNIVERSAL TIMING SYSTEM.
This is the most important point to understand before learning PC and CO terminology.
Average-speed regularity
The organizer prescribes an average speed for a section. The crew uses distance and elapsed time to stay on schedule. Timing may be checked at intermediate or secret controls.
DISTANCE+TIME=AVERAGE
Target-time / precision timing
The organizer defines a target time or target moment. The crew is scored on how closely the actual passage matches that target.
EARLY0.00LATE
Why this matters: the terms used at one rally may not map perfectly to another. “PC”, “CO”, “regularity test”, “time control” and similar labels can be event-specific. EZ Rally therefore treats the organizer’s definitions as authoritative.
03 — THE MATH BEHIND REGULARITY
DISTANCE, SPEED
AND TIME.
The basic relationship is simple: if the organizer gives a distance and a prescribed average speed, the corresponding target time can be calculated.
DISTANCE40 m
÷
SPEED18.0 km/h
=
TARGET TIME8.00 s
At 18.0 km/h, a car travels 5 metres per second. Covering 40 metres therefore takes 8.00 seconds. In a real rally, the roadbook or organizer may provide the necessary distances, speeds, target times or tables directly; the exact procedure depends on the event.
This is why accurate distance measurement, timing and clear communication between driver and co-driver matter so much in regularity competition.
04 — PC-STYLE PRECISION TIMING
WHAT DOES A
PC DO?
In the PC-style workflow supported by EZ Rally Timer, the crew aims to cross a defined line at a target moment. The difference between target and actual passage is the result.
CAR →
PC LINE
Crossed 0.20 seconds before the target.
Crossed at the target moment.
Crossed 0.20 seconds after the target.
What the crew is actually doing
As the car approaches the line, the driver controls the car’s speed and position while the co-driver follows the timing information. In EZ Rally Timer, the countdown can continue through zero if the line has not yet been crossed. The app does not assume that reaching 0.0 means the car crossed the physical line.
When the car actually crosses the PC line, the co-driver taps. That tap records the crew’s passage in the Timer workflow and advances to the next configured control.
05 — SPC, PC AND CO
THREE TERMS USED
BY EZ RALLY TIMER.
These labels describe the control types that can be entered in EZ Rally Timer. They should be read as app terminology for a supported rally workflow — not as universal definitions for every regularity rally in the world.
SPC
Start of the timed sequence
SPC marks the start used by the Timer for a configured sequence. The co-driver starts the sequence at the actual start. From there, the app follows the controls entered for that Day.
PC
Precision control
A PC is handled as a precision-timing point. The Timer shows relative timing to the target and continues past zero when necessary. The co-driver taps at the actual line passage.
CO
Time control
A CO is handled differently from a PC. EZ Rally Timer presents absolute clock time for the control, and the co-driver taps at the actual passage. The organizer’s procedure determines how the control must be approached and recorded.
06 — PC VS CO
SAME RALLY.
DIFFERENT JOB.
PCRELATIVE TIMING
8.00 sec
Think: “How close am I to the target moment?”
- Countdown toward the target
- Can show overrun after zero
- Co-driver taps at actual line passage
- Result can be expressed as ± timing difference
COABSOLUTE TIME
10:42:18
Think: “What is the actual clock time?”
- Uses clock time rather than PC-style countdown
- Co-driver confirms actual passage
- Procedure and penalties are event-specific
- Official event rules always control
07 — A SIMPLE EXAMPLE
FOLLOW ONE SEQUENCE
FROM START TO CO.
The example below is illustrative, not a universal rally rule. Its purpose is to show how the three control types can form one Timer sequence.
CONTROLINSTRUCTIONWHAT THE CREW DOES
SPCStart at 10:00:00Co-driver starts the Timer at the actual start.
PC 0140 m · 18.0 km/h · 8.00 sApproach the line and tap at actual passage.
PC 0240 m · 18.0 km/h · 8.00 sFollow the next target and repeat the precision pass.
PC 0340 m · 18.0 km/h · 8.00 sUse the countdown, distance and speed information as configured.
COTime controlUse absolute clock time and follow the organizer’s control procedure.
SPC→PC 01→PC 02→PC 03→CO
08 — THE CREW
DRIVER AND CO-DRIVER
WORK AS ONE SYSTEM.
Road. Car. Line.
The driver’s priority is driving: road position, traffic, speed, braking and the physical control line. The driver must not interact with EZ Rally while driving.
+
Roadbook. Timing. Tap.
The co-driver manages the roadbook and timing information, communicates with the driver and operates the Timer when permitted by the event and local law.
Safety comes first. Set up the app before driving. If interaction is required while the vehicle is moving, it should be performed by a co-driver or passenger where permitted. Always follow local traffic law and event regulations.
09 — WHY TERMINOLOGY VARIES
READ THE EVENT
BEFORE YOU READ THE APP.
Regularity rallying has developed across many countries, clubs and championships. The underlying idea — precision — is shared, but the implementation is not universal.
FIA historic regularity descriptions emphasize maintaining a prescribed average speed across a section, often with intermediate timing controls. Other events may use known timing lines, target-time tests, secret controls, TSD-style instructions or local terminology. A term that means one thing at one event may be used differently elsewhere.
Configure EZ Rally to match the event — never reinterpret the event to match the app.
10 — HOW EZ RALLY TIMER FITS IN
THE COMPETITION FIRST.
THE TOOL SECOND.
Once you understand the event’s timing system, EZ Rally Timer helps present the information in a clear, purpose-built workflow.
During a configured PC
The main screen brings together the current control, remaining time, distance, target speed, current speed and the next control. The co-driver uses the actual line passage as the trigger.
Before the rally
Events, Days and controls are prepared in advance so the competition workflow stays focused and predictable.
EXPLORE EZ RALLY TIMER →SOURCES & FURTHER READING
BUILT ON
ESTABLISHED PRINCIPLES.
This guide separates general regularity-rally principles from the PC/SPC/CO terminology used by EZ Rally Timer. For broader context, we recommend primary and specialist references:
FIA — Introduction to Historic Regularity RallyPrimary-source explanation of regularity sections, prescribed average speed and timing controls.RallyGuide — RegularityAccessible glossary covering regularity, average speed, regularity tests and related terminology.RallyGuide — Average SpeedExplanation of prescribed average speed and its role in regularity competition.
EZ Rally is not affiliated with FIA or RallyGuide. External references are provided for education; the rules of the event you are entering remain authoritative.