In the previous two articles (HERE and HERE), we discussed planning, purchasing and installing your data capture system. At this point, you’re ready to take it to the track! This week we’re going to discuss how to capture and use that data with as minimal frustration and hassle as possible. There’s a lot to learn here, so take baby steps on your way to becoming an expert at data capture and analysis.
Before you load up and head to the track, there are a few things you might do to make that first trip with the new equipment go more smoothly. With new systems on the car feeding you data, and the need to make sure all sensors and inputs are working properly, the whole process may seem overwhelming at first. You can practice taking logs at home before going to the track, for example, when warming up the engine. You should practice until you can start, stop, and view the datalogs with ease. You should already be able to locate each input channel and know how to enable or disable the display on your charts. You should know how to connect your laptop and download datalogs, and know how to save or store them, and bonus points if you learn how to locate and attach those datalogs to emails so that you can send your logs to people who may need to see them. You may want to share that data with your torque converter manufacturer so they can help you pick better parts, or you might need to send data logs to your EFI tech support team to help debug a problem you’re seeing. It’s important to know how to perform these tasks comfortably at home before you need to perform them under stress at the races.
Additionally, it’s a great idea to create a checklist for yourself and your crew, especially since you’ve added complexity to your program. Make sure you know who will be responsible for starting the data recordings if you’ve configured your system for manual start. If you’ve set automatic recording, then make sure the logs are starting as you intend, again by practicing at home. Make sure to include the data downloading process in your checklist, and have a storage plan for the datalogs in place so that you can save all your runs and refer back to them easily.
Oftentimes, tuners will use filenames to indicate the event, date and performance of the pass when they’re saving data files to a laptop. You may want to store the files in folders that are named for each event, with names like “Q1 6.85 220” for each run file. Racepak datalogs will even store atmospheric conditions or your own custom data with each run so you can get as deep as you like into performance analysis. Spend time learning these tools and the best practices that the manufacturers recommend and you’ll ease the transition into this new technology by a lot!
Next, its time to make a pass and see how everything works. First, don’t let your new equipment distract you from the basics you already know so well. Data capture takes a back seat to safety every time, so make sure the car is ready and you’re ready to make that pass. Consider making an easy run just to make sure you’re getting good data. If you’ve done your homework here, the data capture should happen almost by itself, and in some cases, completely without human intervention (if you’ve configured your system for automatic capture). Once the pass is complete, get the car back to the pits and grab your laptop—it’s finally time to look at real data.
Back in the pits, it’s time to pull the data from your ECU or logger. You’ve practiced this already so it should be a no-brainer, right? Pull up your datalog, and zoom in on the time that interests you: launch through shutdown. This can be found by looking at the Throttle Position or RPM data, you’ll see exactly where the car was running wide open and will be able to zoom quickly on that part of the log file. One of the first things you should do is disable data views that you do not need to see. It’s very difficult to look at more than a few channels at a time, some systems let you create multiple charts on a single screen, while others require you to select data fields for viewing all on one timeline.
We recommend starting simple with just RPM, driveshaft speed and throttle position. Then add channels one at a time as you decide to look at them: oil pressure, transmission line pressure, air fuel ratio, etc. Most logging systems allow you to save different views of data so you can easily switch between groups of channels without having to individually add or remove them from your current view. It’s worth spending a little time at home learning more about how to navigate your logging software, and most manufacturers have great online resources to show you how. At some point you will want to go through each channel you’re using just to make sure they’re working properly. If you have problems seeing the data, it can be configuration error, or a wiring problem, or even a bad sensor. Check with your manufacturer’s technical support team if you can’t quickly figure out the problem.
Congratulations, you’re now capturing data like a pro! And chances are good that you will want to add more channels as you get more comfortable with data logging. Hopefully you’ve prepared by having plenty of spare inputs as we suggested previously, because you can never have too much information about your car’s performance. Now go out there and use that data to your advantage!
Scott Clark is an independent EFI tuner who works with a variety of different engine management and data capture systems. He focuses mainly on engine and powertrain electronics, and has tuned engines in a variety of venues including landpseed, drag racing, Engine Masters Challenge and even emissions-compliant stationary engines. Scott also teaches EFI installation and tuning classes through his company RealTuners, www.realtuners.com.