Race Car Data Logging

All Forms of Pro. Motorsport use Data Logging, But What is it?

Aug 14, 2009 John Glimmerveen

From lap timing to recording every conceivable aspect of a race car, data logging is an essential part of modern motorsport.

Data logging systems have been in motorsport for more than 25 years. In the early days, the systems merely recorded lap times, but teams soon realized that recording data for later analysis was an invaluable tool. Not only could the analyzed data be used to improve the car’s performance, it could also help to improve driver performance.

Rapid Development

As with all motorsport components, the competitive nature of the sport has lead to rapid development of the available systems. Engineers can now view ‘real time’ data as the car travels around a track, and drivers can examine theoretical fast laps to see where they can go faster and/or reduce their lap times. Also, it is possible to measure tire temperatures and pressures in 'real time' adding greatly to driver safety.

All data logging systems consist of the following base components:

Sensors
Recording device (data logging unit for data storage)
Triggering mechanism (an infra-red beacon placed at the side of a track starts the system)

For the average race car, the following sensors will be used:

Wheel speed sensors (at least one, often on all four wheels)
Throttle position sensor (measures the angular change of the steering wheel)
Gear position sensor (monitors the selected gear – shown as a number on the dash assembly)
Lateral ‘G’ meter (quantifies the amount of sideways resistance to cornering in units related to gravity)
Longitudinal ‘G’ (quantifies braking and acceleration in units related to gravity)
Shock travel sensor (measures the linear distance traveled by a shock absorber, or damper)
Brake pressure sensor (can measure brake line or pedal pressure)

The sensors monitor movement or temperature change in a preset locations: wheel rotation, for instance. Depending on the sophistication of the system (and associated expense), all moving parts and all parts subject to temperature change can be measured. In addition, flow sensors can determine the amount of air pressure or air flow, much like those used on aircraft. In the case of race car applications, these flow sensors can be used for testing radiator air flow, and for aerodynamic applications.

Typical Engine Sensors

In addition to the sensors noted above, the engine and transmission can have multiple sensors to continuously monitor performance. Typical engine sensors include:

RPM (revolutions per minute of the crankshaft)
Water temperature (often preprogramed to warn the driver when the temperature exceeds a set parameter)
Oil Temperature (as above)
Oil pressure (monitors the dynamic oil pressure again, with preset warnings if the pressure moves beyond a set range)
Battery voltage (as some of the components on a racecar – including the logging system – are voltage sensitive, the battery must operate within a set range)
Cylinder head temperature (as combustion takes place, the engine settings will compensate for fluctuations in the heat generated)

Track Maps

Of particular importance to the driver is a track map (combined with the associated data – speed, position, rpm – etc.). Track maps are a visual aid to the driver for analysis. He can zoom into any given part of the track to check that he is driving as fast as the car (and conditions) will allow. For instance, a driver may wish to see if he can brake any later for a given corner; if he found that he was releasing the brakes early (and coasting before turning into a corner), he would know that it was possible to brake later.

Some older driver’s referrer to data logging systems as ‘tell tales’. In reality, the system only adds data to his observations. Sometimes this data will indicate that the driver’s observation was wrong (he thought he was changing gear quickly, for instance) but ultimately the driver must make the final decision about driving changes or car set-up changes – it is his life on the line after all.

Computer Memory

Of particular importance within motorsport of data logging devices is the information they can supply to a race engineer. Experienced professional drivers will remember many aspects of a given lap, but the human brain cannot remember the intricate detail of so many parameters that a computer can.

The race engineer will analyze the data from a track session to see where a car can go faster. He may decide that the suspension needs adjustment (for example) or he may decide that the driver needs to change his approach to a certain corner. Working with the race engineer, a driver will study every aspect of the recorded data to maximize his driving and also to increase, wherever possible, the performance of the car.

The most popular systems are manufactured by: Motec, Stack, Cosworth Electronics (formerly Pi), and Aim.

Development is ongoing with all the various systems, but most companies supply a base system that can be added to as the team/driver progresses.

The copyright of the article Race Car Data Logging in Auto Racing is owned by John Glimmerveen. Permission to republish Race Car Data Logging in print or online must be granted by the author in writing.

Typical logged data display