Grab a snack, this will take a bit. For those that are really interested in learning an overall process, you?ll want to open the links, download the logs, and try to follow along. This is all based on Cobb information, and I'm breezing over a lot of info simply due to brevity. As stated multiple times throughout, this is only an example of the overall process to show how you can use the different programs in conjunction with each other when datamining.
Before we get started, here is the link to Cobb?s monitor list (as of this writing)- COBBS MONITOR LIST. Become familiar with your monitors and what is/isn?t applicable to our platform, and try to think about how each monitor is used in and relates to the overall system as a whole. With enough datalog evaluation you?ll start to be able to have a deeper understanding of not only what is logged but how that particular monitor is related to other monitors and the engine as an entire system. Take note of the fact that some of the parameters are inferred and therefor cannot be fully relied on as absolute data, but their presence can still be used and referred to when making general conclusions.
There?s no way that I can walk you through every-single possible comparison scenario in a reasonable amount of time. For this thread I?m going to use one single comparison that I?ve gathered from some of the current personal testing that I?m doing, but the overall process is the same for pretty much all others-what changes is the data logged, how you log it, and how you choose to view it. You can (and will) compare two logs a multitude of ways depending on what it is you?re looking for or evaluating.
For the sake of this thread we?re assuming that you already know how to get consistent datalog information (DATALOGGING 101) and already know the quality of your fuel (YOU'RE USING INFERIOR FUEL). You can pull up the logs I?m using here (open them up in separate tabs on your ?puter)-
87 Octane Testing, 87E10
87 Octane Testing, 93E0
I think you can download the actual Excel files if you scroll down below the chart and spreadsheet, and if not feel free to PM me if you want to use them to practice pruning or whatever. I use Excel for the majority of my actual data comparisons and I only use Datazap as a means to quickly view an overall relationship or to chart a pretty line for posting on here. Logs 2 and 4 are both heading NW and 3 is SE on 87 octane, then 5 and 7 are heading NW with 6 being SE on 93 octane. All six runs were done on the Cobb 93 octane Stage 3 OTS tune.
The first step in any comparison that I do is upload it to Datazap for an overview. I do this to make sure that my data is clean and get an overall picture of whatever data I?m going to be comparing, which is going to be ignition corrections and timing for this example. I will verify that no related parameters are too far from each other (coolant/oil temps, etc) and generally make sure that they are all ?similar? within the before and also within the after, and then as a whole. All this is is a check on overall consistency.
If everything looks close, the next step that I do in most performance evaluations is prune the log to only show me what is happening at WOT. To do that, go up to the Trim button (towards the upper right above the chart), select Accelerator Pedal Position % and move the left slider all the way to the right (100%). This is going to prune the chart to only show what was logged when my foot was on the floor. I also remove the Boost Pressure monitor because it?s not something we?ll be looking at in this instance.
Now that that is done, open up all four ignition corrections in both charts. What you should notice once you look at it long enough is that even though both show mostly positive corrections with some reductions, chart 5 is generally more consistent, has fewer reductions, and shows mostly higher corrections. This is to be expected because the effective octane is higher, but here you can visually see it.
Next we?ll add the Ign Timing Cy 1 monitor to the chart. That monitor is showing the timing for cylinder 1 after corrections, and if you go to 5992 rpm on chart 2 you?ll see that that cylinder in my car had 10.3 degrees of total timing advance at that RPM. Moving over to chart 5 and 5997 rpm you?ll see that that cylinder is now achieving 15.13 degrees of advance. Again, not anything that we didn?t expect, but you can now visually confirm the difference.
Before we get started, here is the link to Cobb?s monitor list (as of this writing)- COBBS MONITOR LIST. Become familiar with your monitors and what is/isn?t applicable to our platform, and try to think about how each monitor is used in and relates to the overall system as a whole. With enough datalog evaluation you?ll start to be able to have a deeper understanding of not only what is logged but how that particular monitor is related to other monitors and the engine as an entire system. Take note of the fact that some of the parameters are inferred and therefor cannot be fully relied on as absolute data, but their presence can still be used and referred to when making general conclusions.
There?s no way that I can walk you through every-single possible comparison scenario in a reasonable amount of time. For this thread I?m going to use one single comparison that I?ve gathered from some of the current personal testing that I?m doing, but the overall process is the same for pretty much all others-what changes is the data logged, how you log it, and how you choose to view it. You can (and will) compare two logs a multitude of ways depending on what it is you?re looking for or evaluating.
For the sake of this thread we?re assuming that you already know how to get consistent datalog information (DATALOGGING 101) and already know the quality of your fuel (YOU'RE USING INFERIOR FUEL). You can pull up the logs I?m using here (open them up in separate tabs on your ?puter)-
87 Octane Testing, 87E10
87 Octane Testing, 93E0
I think you can download the actual Excel files if you scroll down below the chart and spreadsheet, and if not feel free to PM me if you want to use them to practice pruning or whatever. I use Excel for the majority of my actual data comparisons and I only use Datazap as a means to quickly view an overall relationship or to chart a pretty line for posting on here. Logs 2 and 4 are both heading NW and 3 is SE on 87 octane, then 5 and 7 are heading NW with 6 being SE on 93 octane. All six runs were done on the Cobb 93 octane Stage 3 OTS tune.
The first step in any comparison that I do is upload it to Datazap for an overview. I do this to make sure that my data is clean and get an overall picture of whatever data I?m going to be comparing, which is going to be ignition corrections and timing for this example. I will verify that no related parameters are too far from each other (coolant/oil temps, etc) and generally make sure that they are all ?similar? within the before and also within the after, and then as a whole. All this is is a check on overall consistency.
If everything looks close, the next step that I do in most performance evaluations is prune the log to only show me what is happening at WOT. To do that, go up to the Trim button (towards the upper right above the chart), select Accelerator Pedal Position % and move the left slider all the way to the right (100%). This is going to prune the chart to only show what was logged when my foot was on the floor. I also remove the Boost Pressure monitor because it?s not something we?ll be looking at in this instance.
Now that that is done, open up all four ignition corrections in both charts. What you should notice once you look at it long enough is that even though both show mostly positive corrections with some reductions, chart 5 is generally more consistent, has fewer reductions, and shows mostly higher corrections. This is to be expected because the effective octane is higher, but here you can visually see it.
Next we?ll add the Ign Timing Cy 1 monitor to the chart. That monitor is showing the timing for cylinder 1 after corrections, and if you go to 5992 rpm on chart 2 you?ll see that that cylinder in my car had 10.3 degrees of total timing advance at that RPM. Moving over to chart 5 and 5997 rpm you?ll see that that cylinder is now achieving 15.13 degrees of advance. Again, not anything that we didn?t expect, but you can now visually confirm the difference.