Data Logger results

[addictionMS]

Just interested in what you are looking at and where you are getting the most value out of the data?

Jim

[Jack Olsen]

I'm just taking baby steps with my DL1, but looking at segments, and overlaying a best lap with others made with slight changes to the setup -- the graphing function -- are what I'm getting the most out of right now.

I'm looking forward to video overlaid with data, but the obstacle is my absolute unfamiliarity with the Windows-based laptop I have to use with the data logging software.

[cstreit]

I've been using it to compare suspension setups...

I'll take the same corner over say, 20-30 laps. Then look at the total average lateral G's in the various corner sections. Say entry to apex, and also apex to exit. Then calculate the average G for that section and see how it changed. Must then also look at exit speed.


This is a good topic Jim. Perhaps we can start a thread with the coolective knowledge of our most useful analysis with the tool. I for one still find it difficult to get a lot of useful information without spending a ton of hours on the data.

[addictionMS]

I was hoping that there would be a lot of knowledge out there, but if not, then a lets use this thread to gather ideas and archive them.

I have just started reaping value out of mine, I had some issues with the GPS data, seems that the analysis software discarded any GPS data where there were less than 8 Sat in the sky, so most of my data was bad. Ended up sending my DL90 and results back to Race Technology and after a few weeks of testing they found the bug (software of course) and I am all set to go. So I am now dangerous with the DL90 and hope to spend more time looking at it and comparing the data. It looks like we will have atleast four Toyo Cup cars running DL90s so we should be able to get some good results.

Jim

[john_colasante]

I like to put the unit in another (faster) guys car and then overlay the runs to see the differences.

[Dave at Pelican Parts]

There's an article in the newest Grassroots Motorsports about communication with your race engineer. (Even if that engineer is yourself.) They talked about, among other things, considering a turn in at least three parts--turn-in, steady-state cornering, and track-out.

Might be worth a read; sounds like at least some of the concepts also apply here. The article was quite general, though, so it might not have the specific type of recommendations you want.

--DD

[cstreit]

Originally posted by john_colasante
I like to put the unit in another (faster) guys car and then overlay the runs to see the differences.

That would probably a valuable data point. I have tons of data, but unfortunately all you DL-90 owners are left-coasters!

[addictionMS]

we will have four DL90s running in Toyo Cup soon,

so far my greatest bang for the buck effort has been color mapping the % of time slip, so I can see wher I consistantly am loosing the most time, giving me one or two corners to work on.

Jim

[cstreit]

I haven't used that feature yet. REally gotta read the new manual! Very cool feature!

[logician]

Here's what I wrote recently to a friend that asked about data logging. My experience is with the Mychron XG-Log system, which I have installed in both my GTS and SM race cars.

1) I like programmable shift lights on the Mychron. Those are helpful for optimizing your shifting. But they can also be used to give feedback on performance. For example, you can set one to light up at the target RPM for T2 at TH (a sweeper). No light in the turn means go faster.

2) I like the lap time display, which in addition to displaying your last lap time, will also display your best time for the session. Best time is especially helpful for qualifying.

3) The MXL has predictive lap timing, which tells your relative time vs. your best lap as you go. It''s kind of like the ghost car in Grand Turismo. So for example, on a particular lap, you know that going into T9, you are behind by 0.1 seconds. This is a good coaching tool to help you pick up the pace.

4) When I analyze the data on my laptop, I compare a known good lap vs. my current lap. I usually focus on speed traces and compare performance in different segments. It is helpful to look at the maximum speed before braking, and the minimum speeds in a turn. The max speed tells you how well you exited the last turn. The min speed tells you whether you are over-braking. Relative segment times are also helpful. After looking at a trace, it's pretty clear what you need to improve.

5) Related to point 4, it is really really really helpful to exchange data with other drivers. Thus you can see where each driver is quicker and why. This can help give you some confidence that more speed possible in certain turns. Unfortunately, the software will generally not allow you to share data between systems. So you are limited to exchanging data with drivers that are using the same system as you. Consider which drivers you might want to exchange data with when you select a system.

6) Studying RPMs can be helpful to analyze shift points, and predict better gear choices. You can also drive turns in different gears, and then look at the data to compare the results (exit speed and segment times) and objectively decide which approach is better. Another example is analyzing optimal gear choices in a start, where you might not be fully up to speed.

7) On systems that have wheel speed sensors, you can see lockup in the traces, since the wheel speed glitches to zero. You can also compare the longitudinal G's with lateral G's to analyze the degree of trail braking.

8) Because the system monitors RPM, it will log mechanical over-rev conditions. This is helpful to understand the degree to which an engine might have been stressed.

9) Logging temperature and oil pressure can be really helpful to monitor critical engine issues. Oil starvation can be seen in the logs, where you might not notice it otherwise. Same with temps. You can program four alarm lights on the Mychron to come on under critical conditions. Maybe this will save your engine.

There's a lot more that you can do with the system. But those are the basics, and mostly how I use it.

-Juan

[69911e]

Depends on what you are looking for. I found for suspension tuning, tire temp profile across the tire is important. Using a datalogger for this will allow you to see the temp profile of each tire in each corner(much better than the average temp of a tire you will get in the pits using a standard pyrometer). I installed 3 infrared sensors per wheel mounted on a bracket attached to the hub. This allows the sensors to move with wheel travel and monitor a consistent spot on the tire. I also added engine RPM,throttle position, brake, and a 3 axis accelerometer.
Once the data is gathered the most important step is processing it. By looking at the 12 tire temps sensor data, you can make a much more informed decision on suspension adjustments and modification.
ED

[addictionMS]

As I play more with the data, I think it might be a good idea ot think about the effort of analysis along two dimensions, one is driver improvement, the other is car improvement.

Clearly what Ed was doing was car improvement, color coding the track map based on % of time slip (same kind of measurement at Juan' s "predictive lap timing") is more directed at driver improvement.

I know for the time being I am focused on driver improvement. That said, I think I will focus on adding driver imput data to my collection, so far I have been logging the brake lights as a digital input. I am adding throttle position before the next race. I am also testing out the video and data merge. It looks like Race Technologies will allow a nice over lay, but almost more important, you can watch the video of a fast sector and a slow sector side by side in the analysis software, and que it up based on the sector analysis table the provide. I am hoping I will be able to based on seeing my line in the video, and watching my braking and throttle, I will be able to see what I did different in the faster lap and build a visual model for me to attempt to repeat.

I have also been told, that putting a brake light on your dash so it getsw captured in the video is a good analysis tool, when reviewing videos. Poor mans version of data overlay.

Jim