Little black box

Modern aftermarket engine management systems have developed and progressed a lot in recent years, most higher end aftermarket engine control units (ECU) now contain data recording functions, these can be activated in various ways.

Here we are going to describe one of the ways you can activate the ECU data logging in the Link G4+ and Vi-PEC ‘iSeries’ ECUs.

Firstly, you need to have the software already installed on your computer, if you don’t it can be downloaded HERE, open it, make sure you’re physically connected to the ECU and select ‘Connect to ECU’ under ‘ECU Controls’ or alternatively press ‘F3’

Link / Vi-PEC ECU connection

Connecting software to Link/ Vi-PEC ECUs

Now you need to set up your logging, this is found under the ‘ECU controls’ tab, ‘ECU Log File Setup’ or as we’re showing here, under the ‘Logging’ tab and ‘Logging Setup’. This gives you the option of setting up data logging with the PC connected or, as we’re going to do, ECU data logging.

data recording

Logging setup

Once you have selected this a new window will open up, this is where you choose the ‘ECU Logging’ tab, check the ‘enabled’ box to enable the ECU logging.

Data recorder

ECU datalogging

With ECU logging enabled in the ECU you now need to decide what you will use to activate the logging process and how long each log will last. We usually use throttle position (if the throttle is opened more than the set value, here we are using 50%, logging will begin) and record for as long as possible using the ‘off delay’ (if this is left at ‘0’ then it will only log whilst the activation condition is reached, here we have chosen the longest duration of 25 seconds). This means that once the logging is activated it will log for up to 25 seconds after the last activation.  Other options for activating the logging are RPM above a certain range, MAP above a certain value or even something as simple as a switch.

You also need to decide what parameters you want logged, key parameters can be added by clicking ‘Add Default’, you can set up and save your own default parameters. Every parameter of the ECU can be found in the left hand box (Available Parameters); to get the ECU to log it you click on the parameter you want logged and press the ‘>>’ button in the middle, this will put the data streams in the right hand box (Logged Parameters).

how and what is recorded

Choosing areas to be recorded and how to begin recording


For example, during a sprint race the driver will open the throttle beyond half way (50%) when starting their run, they will lift off for a corner and open the throttle again to accelerate through and out of the corner, as this will usually involve a lift off of 1-3 seconds the data recorder will continue to record data during the light/partial throttle (less than 50%) area and then the counter will be reset as they accelerate again. The counter will continue to be reset until the time in the ‘off delay’ has elapsed and it will put a marker in the data log to identify this.

Here’s a screen shot of a days racing logged:



Certain parameters change faster than others so you can choose the ‘frequency’ in which it’s loggeded (Hz=samples per second). This allows you to increase the amount of data captured for fast changing parameters such as knock levels, injector duty cycles and wastegate duty cycles, or you can decrease the amount of data captured for slower changing parameters such as coolant temperature or altitude. As there is only 4MB of datalogging available on some models if you log everything at full frequency you will only be able to log approximately 14 minutes of data before it will either stop or begin to overwrite the logged data, by only choosing what needs to be logged and at sensible frequencies you can log between 1 and nearly 7 hours of data, the Link G4+ Fury, Xtreme and Typhoon have 32MB. This is set up like this:

Sample rates

Choosing data logging speeds

With everything set up you must now save your settings into the ECU, first click the ‘Ok’ button


And then the changes will need stored, this can be done by going into the ‘ECU Controls’ and choosing ‘Store to ECU’ or simply pressing ‘CTRL’ and the ‘S’ button on your keyboard at the same time.

Storing changes

any changes to the ECU are stored

If you don’t complete this step all changes that you have made will be lost when you disconnect from the ECU.