Data Aquisition - What do you use?

[gran racing]

I get how to use the software, but like Joe said don't comprehend what to do with the data. Jeremy L., I know you showed me some stuff before but that was waaay over my head. At the same point I understand that wasn't our goal for that day. Articles and books on this subject are okay, but the way I personally would learn this stuff is more hands on and looking at the real system. I bought one of the new data acq books that discusses the Dl1 system but again, over my head. I think if someone were to conduct a few online classes using something like GoToMeeting or other similar on line meeting software, there would be interest. Again, keep it simple and only include the most basic inputs.

[rsportvolvo]

Most DAS software is well laid out and quite user friendly. As most folks are mentioning it's what to do with the data once you have it. For that you are going to have to read up, find a mentor, take a class, and/or hire a DAG.

I took Claude Rouelle's seminar @ 6 years ago and it is a very good primer. I recommend a hands on seminar for anyone wanting to use DAS. Additionally the best book on the subject matter, that I've read, is Jorge Segers new book (see my previous post for details). This book tells you the sensors you need, math channels to program, and how to review the "squiggly lines." He does so using various cars, various DAS, and puts it quite plainly. I can't say enough about this book and the knowledge you'll gain from it.

Data analysis is on the technical side of the sport. With that you will need to hit the books (i.e. back to school for most). You don't have to be an engineer to correctly utilize the data, but you have to think like one.

[924Guy]

Went back and looked - duh, the stuff is already on my website, just never linked it in:
http://vaughanscott.com/AIM/Data_Acq.htm

There's a Powerpoint presentation there, plus you'll want the notes page to go with each slide.

Some of the info about systems is a couple of years old now, but all the analysis stuff still applies!

[Andy Bettencourt]

We do session to session comparisions, 2, 3 and 4 driver overlays all the time. We go over every corner, braking points, effectiveness, mid corner speeds, corner exit, resulting straight speeds etc.

Its all in there and easy to see once you have seen it a couple times.

Contact me if you want to be part of a seminar at our shop.

[jlucas]

I think I would probably prefer something that is showing me where on the track I am at when I am gaining or losing time as opposed to a graph, or a bunch of "squiggly lines".

Here's a DL1 example showing a graphical indication of where time is being lost or gained for a single lap. + is slower (red) , - is faster (blue), green is on pace. The comparison is done against "best theoretical" baseline which is the compilation of all your fastest sectors strung together. As your more consistent, the best theoretical converges on what is actually achievable. (linked so you can see them larger and not clog up the forum):
http://i267.photobucket.com/albums/i...lip-shaded.jpg
So that's one way to look at it. If you look at that same lap compared to another in a more traditional view, you can see multiple channels at the same time, and quantify some of the difference why one lap is faster than another. Any of the light blue text, arrows, boxes are my manual markup on top of the screen grab to point things out to you. Keep in mind this is just 1 option of many available in the software.
http://i267.photobucket.com/albums/i...-slip-full.jpg
The color map trace (image 1) and the bottom graph in image 2 both are showing you the "time slip %" variable which is something unique to the DL1 among it's entry level competitors.

I actually don't care all that much about the video part. It would be cool, but my interest lies in the data; entrance and exit speeds, G forces, braking points, acceleration points, and if available, line on the racetrack.

I could give you a graphical example of each of these in just about any of the software packages (ie. brands). The DL1 advantage here is the speed of jumping from one comparison to the next and the multitude of options to view your data. You can view the information on graphs (aka squiggly lines), in a table, in a colored map trace, or in a animated replay of your session. Different people learn differently so one method might appeal to you, another for me.

Can the DL1 be set up to show you that easily? Or would I need a programming degree? And what about the installation? Is it a 'drop and go' system with minimal wiring?

Yup, that's the beauty of the GPS based systems (any of them) is the amount of information that can be recorded from a 5 min install - GPS position, GPS speed, lateral accel (side to side), longitudinal accel (brak ing/accel). Even just that is information overload already for most people not used to looking at data acquisition. Tapping into analog inputs (TPS, brake, RPM, etc..) will take a little more time and on some systems this starts to drive up the cost but the DL1 has 8 analog/4 frequency/& RPM inputs built in. These extra inputs help you get deeper into the analysis. Some inputs like steering angle are you going to cost you extra no matter what system you go with.

Jorge Segers new book (see my previous post for details). This book tells you the sensors you need, math channels to program, and how to review the "squiggly lines." He does so using various cars, various DAS, and puts it quite plainly. I can't say enough about this book and the knowledge you'll gain from it.

I'll second the Segers' book. Greg has my copy right now.

pros and cons to each, so your particular mission requirements matter ALOT

Very true but most newbies don't know or understand the differences between some of the choices or can understand why one software is better than another. Hence why these types of discussions are very enlightening for those who are starting to look/investigate.

As far as add-ons, one of the best for the DL1 is adding a DASH3lite. Adding a DASH3lite (or buying as a bundle with a DL1 initially) will give you predictive lap time feedback as you circulate the track and cross your virtual GPS lap beacons; GPS speed, programmable shift lights, and many other features are part of it as well. It's a powerful tool to help you while on track, and help you capitalize on what you reviewed on the PC back in the paddock. A DASH3full adds sensor monitoring/display capability as well as programmable alarms for those sensors so you concentrate on the important stuff, you can even start off with a "lite" and upgrade it later to a "full".

Hopefully these visual examples and more specific comments help you in your search. It's hard to know which presentation of the information works for each of you, so if someone wants to see if a different way just let me know. This is why it's important that your software package has options. Also as your data analysis skill grows, what you want to see and how you want to see it will grow/change. You want something that will grow with you.

[Spinnetti]

Several mentioned what do you do once you have the data?

I took a two day driving course at Mid-Ohio, and we did every corner over, and over, and over again, with turn in points, track out points etc.. Once you know what the correct line and points by corner are, all you need to do is look at Planned vs. Actual. If you hit all your marks, you just need to focus on improving segment times (which you can compare from each lap), and if not, now you know which areas to focus on. So..... my advice would be to take instruction from pros if available at the tracks you wish to run on, and you will then know what to do with the data....

[Ed Funk]

OK, 3 cars, 2 drivers, frequently we'll be on track together, so 1 system wouldn't work.
But, if we're in different groups, what would be he best system to quickly remove from one car and put in another?

[jlucas]

Ed, any of the GPS based systems can be easily moved between cars. To facilitate that just get an extra set of connectors & GPS antenna for each car and just move the "brain" unit. You can have a similar flat mounting spot in each car that you can put velcro on, if needed, you can use a secondary strap (think I/O Port camera strap or similar). If your going to use a display, I would also recommend 1 per car - not required but it would simplify things greatly for moving.
So that condition alone won't help you pick a unit, however the speed at which you can sift through large amounts of data and skip from one comparison to the next I don't think can be beat with the DL1. I can tell you from working last year in GrandAm with 6 drivers & 3 cars at once that my opinion on this has been further reinforced by the driver's comments and the comparisons they made to other systems that data has been presented to them in the past.

[almracing]

This has been a very interesting thread. The info at Jeremy's site was great to get an understanding of the DL-1 from a potential buyer.

I am looking seriously at a DAS this season (don't tell my wife... lol). My Hot Lap timer is great to tell me which lap was fastest... but can't tell me why I was faster. I would really like to know!

If anyone can answer a couple of questions:

1 - Do you have to download the data after each session? (ie does it record over a previous session?)

2 - Do people just use a couple of CF cards for data collection to keep sessions separate?

3 - How long does it take to download the data to a laptop?

4 - Jeremy notes in his information that GPS shift makes it difficult to compare "lines" from one day to another. That I can understand. Does that also include acceleration and braking points?

Thanks!

I am an engineer so I love data... but I also don't want to spend too much time trying to figure out the software, etc.