 Amy here again and welcome to another episode of Cobb U. In our last video we talked about the access port and how it's the gateway to the ECU but we also talked about how it's not only just used to flash tunes but how it can also monitor and help diagnose possible issues. While viewing up to six gauges on the access port can be convenient for daily use, sometimes you need to get a more detailed vision of how your engine's performing. That's because it might not be running right or because maybe you or your tuner in the process of tuning it. The information is very powerful and simple to record with a data log using the access port. So today we'll go over the basics of data logging from setup to how to obtain a good log and finally how to view the data. The first and most important thing we need to do is to collect the proper information. If your data log's too short you won't have enough data to analyze and if your data log's too long well then you're just gonna have way too much information to sort through. To do this we're gonna go to gauges on the main menu. Then we'll go to the arrow at the top and press OK and then we'll go to configure data logging. We have a default data logging list set up but we can add or remove individual monitors to that list. What monitors you add or remove is dependent upon what information you need but more importantly what kind of car you have. Each make model is different so you need to have a good understanding of what monitors are used on your car. So just like we did in our last episode we're gonna have a link in the extra credit to each make and what monitors are used. Now for the sake of today's demonstration we'll keep our data log on the default list. Once you're ready to begin data logging you'll press the OK button while in the gauges function. While the access port is recording a data log a single blue light will appear and oscillate through the shift light. To stop data logging just press the OK button again. Now that you're set up it's time to data log. Now to do this you're gonna do what is referred to as a wide open throttle pool. This will put the ideal load on your car to provide proper boost characteristics and give you good data. To do the pool you're gonna cruise in third gear at about 2,500 rpm. Then you'll start the data log and press the accelerator to wide open throttle and accelerate until you hit near red line. Then you're gonna let off the accelerator pull over and stop the recording. Okay now we're gonna start data logging but before we do that you want to make sure you get yourself to a safe place because we don't want you or anybody else getting into an accident. Okay I'm in third gear and I'm cruising right at 2,500 rpm pressing the OK button to start logging and there we have our oscillating blue light and it says logging underneath so here we go. All right that's it we're gonna slow down we're gonna press OK again to stop logging and now we're gonna head back to the studio and see what we got. Because every car is different I'm not gonna go into the specifics of what the data actually means. Instead I'll go over getting it to your computer and a quick overview of what you'll actually see. First let's get AP manager pulled up. We'll connect our access port to our computer via this micro USB cable and now we see everything on the access port so let's filter out only our logs. Let's drag them to our desktop and we'll open them up. I'm using Microsoft Excel but any spreadsheet program or data log viewing program will display the information properly. So what are all these numbers? Well this is your detailed data log and you're gonna look at it one of two ways. One to diagnose symptoms of maybe specific issues that you're having or two just to look at how your engine's performing. When reading your data log the top row will list all the monitors that you selected to record. For the sake of demonstration we've moved some of these columns around but you will see them in alphabetical order. The column on the left is the time stamp during the recording. The access port can record at speeds of up to 60 Hertz that can vary depending on your car and how many monitors are selected. This means it takes a snapshot about 50 times a second. At this rate you will see very detailed information which can equate to hundreds of lines of information. The rest of the cells will be populated by actual data provided by the ECU for each individual monitor. If you're just looking to assess the general behavior of your engine your approach will be a more broad examination. Each vehicle will have a handful of key monitors you would look at initially. You would start by looking at the majority of the log to identify if any of the data within those monitors exceed the acceptable ranges to identify if any particular area warrants a more detailed examination. Accessible ranges does not mean perfect. It's completely normal for the various systems to make adjustments while you drive that's why it's there. Defining what is considered acceptable range will require a bit of homework before the numbers will mean anything to you. If you're recording a data log to diagnose an already known or suspicious issue then your approach will be a more detailed examination. For example if you think that your car is showing any signs of detonation then you can take a look at the data log. When you look at the ignition timing cylinder three you can see that while we were at full throttle during the pool cylinder three is pulling four degrees of ignition timing. This tells us that the ECU is seeing something that it doesn't like and making an active change to correct it. If we were actively tuning the car it would mean that we will most likely want to take some ignition timing out. As I mentioned earlier the amount as well as the specific monitors changes from make to make so if you're unsure about what you're seeing in your log you can just send it over to us at support at cobtuning.com or contact your local pro tuner to take a closer look. That's going to do it for this episode. Thanks for joining us and be sure to subscribe to our YouTube channel so you can check out future episodes. I'm Emmy your host for Cobb U remember check out cobtuning.com for all your parts and tuning needs. Do you like the storage solutions featured in our studio then visit sonictoolsusa.com to get more detailed product information.