How to make a good datalog?

The datalog function, also known as datalogging, allows relevant measurements to be taken based on the manufacturer’s specific datalogging parameters.

What is datalogging?

Datalogging allows real-time collection of ECU data.
This data includes key metrics about engine performance such as:

• Turbo pressure
• Load
• Acceleration
• Air/fuel
• Exhaust gas temperature
• Intake temperature
• Ignition timing
• Short-term and long-term adaptations

Why perform datalogging?

Reprogramming a car without datalogging is like cooking with your eyes closed. Indeed, no one can properly tune an engine without feedback on the changes made. The information obtained from datalogging is crucial to fine-tune the modified file.

Various tools are available to perform proper logs. Autotuner is undoubtedly the most complete and user-friendly tool for doing this under the best conditions. However, if you have a VCDS, this diagnostic tool also allows precise measurements on VAG vehicles and also supports multiple brands. Diagnostic tool suppliers such as Launch and Autel also offer these functions on some models in their respective ranges.

How to perform an accurate datalog?

1. Perform the log in a gear that’s not too short (4th or 5th)
2. Start from low RPM (e.g., 50 or 60km/h)
3. Apply full throttle and click START to begin logging. (In the case of Autotuner, it selects values for you; with other tools, manual selection may be required)
4. Maintain full throttle throughout the log (do not release the gas pedal)
5. Once you reach the rev limiter or gear shift (or around 4500rpm on a diesel), click STOP.
6. Send the log (The log can be submitted directly via the vehicle record in your OLSX account history)

If you're using Autotuner for logging, you can find more information at the link below.

How to use the datalog function with Autotuner | FAQ (autotuner-tool.com)