Data Acquisition

[Scott Malbon]

I'm thinking seriously about data acquisition. A lot of $$ for my racing budget but perhaps a good investment. Any advice or lessons learned would be appreciated.

Scott

[David Ferguson]

Our company, Veracity Racing Data, sponsor a forum with discusion about all sorts of data acquistion questions. You may want to go read some of the older posts there. Here's the link:
Data Acquisition Forum

I have also put some of my own thoughts into a webpage on our company site: Why use Data Acquisition?

Data Systems are great for answering questions. Sometimes the hard part is coming up with the questions you want to ask. For example, a data system can answer the question "Driver X is faster in my car than me, where is he faster?", but can't always answer "How can I go 1 second faster to catch the next car?"

I could write more, but check out those links, there's lots of good information there already. Got questions? I'll be glad to answer either on the other forum or here.

[This message has been edited by David Ferguson (edited October 12, 2004).]

[This message has been edited by David Ferguson (edited October 12, 2004).]

[924Guy]

I just started using a data system this year. Over the course of the season, which was only 3 weekends for me, only 2 of which were at my home track (Waterford Hills), I found over 4 seconds thanks IMO mostly to the data I gathered and analyzed.

I am and continue to be very happy with the system. I'm using an AIM Mychron3 system; mine (Gold Auto XG) cost about $900 plus sensors, but they start at around $400. Supplier:
http://www.motorsports-exchange.com/store.htm#aim

A very important part when shopping is to consider the software available for analysis. I work with in-vehicle data acqusition and analysis at work, and AIM's software stands up extremely well in comparison to the "professional" stuff we use at work. I can't comment on other manufacturer's systems or software, though - just be sure to try it out before you buy it.

Next test planned for the system will be the Last Chance Enduro at the Glen - 3 drivers in 3 hrs. Two of the 3 drivers in my car (2-car team) will be novices to the Glen, myself included. It's going to be very interesting when we all run through the car and compare data after practice, before the race, to see how the Mychron system will allow us to come up to speed and compare our technique.

Hope that helps... feel free to email direct with questions: [email protected]

------------------
Vaughan Scott
Detroit Region #280052
'79 924 #77 ITA/GTS1
www.vaughanscott.com

[This message has been edited by 924Guy (edited October 13, 2004).]

[Greg Amy]

I just got my first shot at using data acq, this weekend during the 13-hour race.

Evan Webb brought an Action Digital DL1 with him to install in Kirk's Golf III. We used it during the test day, the qualifying and practice, and all through the 13-hour race. We were able to overlay the stints of the drivers and discuss where we were each strong, and see where we were each weak, and make suggestions to each other for improvements. The bottom line is that we all dropped our lap times about *10 seconds* during the test day alone using this information. I managed to lop off *another* 3-4 seconds during qualifying and the race.

I'll have more to say about this tool later, but this has got to be the best learning tool I have *ever* used in my many years of racing. As I told the guys, I feel like I've been given a new religion, been reborn into the Church of DL1 Data Acquisition. I feel like I have to go out and spread the good news to all you electronics-fearing heathens...

Like I said, we'll have more to share later, but this is Real Good Stuff.

GregA

[gsbaker]

Quick question: Do any, some, or all of these products overlay data onto the driving video?

Gregg

[planet6racing]

There is one that overlays data onto video, I believe it is the Commander CDS system. I know they are shown in the back of SportsCar in the advertising section... oh wait, I still have it in my history here (I'm starting to shop for something like this):

http://www.competitiondata.com

Be forewarned, though. The video overlay system isn't cheap.

Could someone share a DL1 file with me? I have the software and the demo file from the actiondigital.com site, but it doesn't have the engine connected and I'd really like to see what it does with RPM's and the like.

Also, Vaughn, could you go a little more into detail about the AIM system you have, what you log, and maybe some pictures/snapshots of the data analysis?

------------------
Bill
Planet 6 Racing
bill (at) planet6racing (dot) com

[planet6racing]

Oh, forgot one other question:

David: since you seem to sell all different systems, which do you think is the best bang for the buck and why? Also, of all the sensors and tricks that these systems can do, what is probably the most helpful? I know the accelerometers will give the g's and that will help explain a lot, but what about things like the wheel speed sensors, linear displacement sensors for suspension tuning, etc? Or, is it just better to stick to the basics and not get too deep into it? (I'm going to read the forum link that you posted today, read the other document yesterday. If this is already covered in that, I'm sorry!)

------------------
Bill
Planet 6 Racing
bill (at) planet6racing (dot) com

[gsbaker]

Hey Bill, as a member of your crew I strongly recommend we beg/borrow/steal one of these gizmos for the ARRC.

Does anyone rent? Is it possible to get a stripped-down demo for trial?

G

[924Guy]

Well, the enduro didn't go off as planned; we didn't have more than 30 minutes between practice and race, and due to other issues didn't get the data downloaded in time to review beforehand. We also had major issues during the race leading to an eventual retirement, preventing us from getting much good data. Much work remains to be done on both of those cars.

Anyway. I do have some of the data from that enduro on my website:
http://www.vaughanscott.com/AIM/aim_tracks.htm

I also have some pics of the unit installed in my own car (just used velcro to pop it into the enduro car):
http://www.vaughanscott.com/construction.htm#MYCHRON3

I don't have handy any snapshots of data analysis, but you can download the software for free, grab my data, and play with it to your heart's content.

The system I use is the AIM Mychron3 Gold XG Auto. It records speed, RPM, computed gear, lap time, and lateral g's, plus 4 analog inputs your choice. It also has the realtime display (unlike some units, I guess) of rpm (by bar graph and programmable shift lights), previous lap time, 2 analogs, and your choice of battery voltage, rpm (digital #), best lap time, or vehicle speed. Comes with lap beacon and receiver, speed sensor, and two analog sensors.

I've chosen to use my own (stock) sensors; for now I have oil pressure, water temp, longitudinal G's, and yaw rate logged. For engine tuning I'll switch over to from 1 to 4 EGT probes; maybe all 4 on the dyno, just 1 on the track at most.

I agree it's best value, at this level, is for driver training; for this reason I expect to add a steering angle sensor at some point and run that with yaw rate, oil pressure, and either EGT or decel. I don't find the decel and lateral g's that useful except to show a major glaring issue (would be useful for driver comparisons, though). I find yaw rate smoothness is more meaningful, though of course nothing is ever more important than speed.

The best part is to be able to pair it up with the track map and analyze the incremental gains and losses around the track for specific laps by segment. The best tool by far for finding speed.

I can echo GregA's comments about finding speed. The most telling for me was that over 2 consecutive weekends on my home track (where I've been racing for 5 years), I was able to rip well over 3 seconds off my best previous ever laptimes after I started using the data system - this where I'd already pretty much plateaued. Not quite as earth-shattering as having someone else get in and drive, but still amazing to me.

Considering the cost required to get similar amount of time out of, say, the motor, tires, or suspension (if they were even allowed), the data systems suddenly become VERY affordable!!! Less than a grand for multiple seconds? Portable between cars? More durable than NOS?

Plus, it's really fun to be able to say, without guessing or exaggeration, just how fast you were going!

Oh, yeah - wheel speed sensors, just the one on the rear axle for vehicle speed. You wouldn't know what to do with the rest, unless you're trying to perfect your threshold braking. I would also stay away from the linear potentiometers for suspension tuning, unless you have high-end shocks (like the ones we can't run), to tune them. For driver development, you need to know what the driver and car are doing. For the former, the most useful is steering angle; brake and throttle less so. For the latter, lateral and long. g's are a start, yaw rate will really get you there.

Since you're gonna ask (yaw rate is not readily available for these systems) - we're using a production yaw rate sensor from a car equipped with ESP (stability control) - specifically a 2000 Olds Intrigue. You give it power and ground, and it spits out a yaw rate signal and linear accelerometer (long. or lateral, depending on how you mount it). If you really wanted to be a jerque, you could get a couple and use them to try to look at pitch rate and roll rate, along with acceleration in all 3 directions. But that would be the less useful info. As I believe it may have been Carrol Smith once said, "Nothing good has ever been written about the rotation of a car about its pitch or roll axes."




------------------
Vaughan Scott
Detroit Region #280052
'79 924 #77 ITA/GTS1
www.vaughanscott.com

[Greg Amy]

<font face=\"Verdana, Arial\" size=\"2\">Do...these products overlay data onto the driving video?</font>

Gregg, there is a video function within the software, but I did not explore it. I'd suggest contacting Action Digital for more info:

http://www.actdigital.com

(I also note that they are a banner sponsor of IT.com...)

<font face=\"Verdana, Arial\" size=\"2\">...see what it does with RPM's and the like.</font>

That's the even more encouraging part. I'm this excited about data acq and all we used was the built-in sensors! We did not take advantage of any of the analog inputs available, all we used was the internal 2-axis accelerometer and the GPS input. Couple in the tach, wheel speed, throttle position, brake sensor, and a host of other variables and there's some significant time left in the car.

To give you an example, I compared my best day and best night laps. I saw EXACTLY where I was being a wuss at night and where I could have improved my night times (had I another night stint). What's really interesting is that on both laps I *nailed* the Oak Tree turn exactly the same, but was 4 (?) mph slower at the same braking point going into Roller Coaster. The difference? The killer headlight setup! Thus, the additional aero drag of the lights cost us exactly 4 mph and 1 second (!) per lap. How else are you gonna get that kind of detailed information without speculation?

GregA

[lateapex911]

I just ordered an AIM MyChron MXL unit.

If you are building a car, you'd be a fool not to do DAQ.

Here's why: (I needed these things tto) You need a good tach. With memory and shift lights, you're looking at over $300 in some cases. A lap timing system is $300 as well. Add shipping, and you are close to $700.

The smaller display AIM unit has a tach with shift lights, and a lap timer on it. PLUS it does a milion other things.

I ordered the MXL unit, which has a bigger display and does a zillion other things for a little more. I was making a cold air inlet, and ws concerned that I might end up with not enough flow at speed. How can I know for sure? Um...simply...a sensor from NAPA, and this trick box and I should know for sure! I can even set an alarm light to indicate that its;gone negative! How cool these things are.

And as the guys pointed out, I expect that it will be able to help me find a litle (or maybe a lot of!?!) speed, and thats a good deal at nearly any price!



------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[racer14itc]

Originally posted by GregAmy:
I just got my first shot at using data acq, this weekend during the 13-hour race.

Evan Webb brought an Action Digital DL1 with him to install in Kirk's Golf III. We used it during the test day, the qualifying and practice, and all through the 13-hour race. We were able to overlay the stints of the drivers and discuss where we were each strong, and see where we were each weak, and make suggestions to each other for improvements. The bottom line is that we all dropped our lap times about *10 seconds* during the test day alone using this information. I managed to lop off *another* 3-4 seconds during qualifying and the race.

I'll have more to say about this tool later, but this has got to be the best learning tool I have *ever* used in my many years of racing. As I told the guys, I feel like I've been given a new religion, been reborn into the Church of DL1 Data Acquisition. I feel like I have to go out and spread the good news to all you electronics-fearing heathens...

Like I said, we'll have more to share later, but this is Real Good Stuff.

GregA

I'll echo the sentiment about the DL1 data logger. I used the DL1 at Mid-Ohio during the Runoffs and saw dramatic improvements during the week, as well as where I could continue to improve. By using the "lap segment" tool you can see what your theoretical 'best lap' would be if you just DID WHAT YOU ARE ALREADY capable of doing in the car, let alone if you tweak the car. In my case, there's still over 1.5 seconds left at Mid Ohio if I can just drive each segment to my (shown) ability. Saves me $$$ because I don't have to bother with spending $$$ on the car until I extract the maximum from it, and the DL1 shows that.

The cool thing about it is that it is portable (takes about 15 minutes to install the whole shooting match) and very simple to operate. If you have a laptop at the track, downloading the data takes only seconds and within just a couple of minutes you can be viewing track maps, speed vs. distance overlays (for comparing multiple laps of yours and other drivers' laps), etc. The most interesting graphs for me were the lateral g's vs. distance overlays. Showed me where I was using the full capabilities of the car in the corners and where I was wimping out. It also shows if you are early apexing or late apexing corners if you know what you are looking at!

The data logger is practically fool proof and the software interface is very user friendly. Best bang for your buck in racing, IMHO.

MC


------------------
Mark Coffin
#14 GP BSI Racing/Airborn Coatings/The Shop VW
Scirocco
Zephyr Race Coaching and Consulting
http://pages.prodigy.net/Scirocco14gp

[This message has been edited by racer14itc (edited October 26, 2004).]

[David Ferguson]

Sorry, I haven't kept up with the postings in this topic. Specifically I was asked:

<font face=\"Verdana, Arial\" size=\"2\">David: since you seem to sell all different systems, which do you think is the best bang for the buck and why? Also, of all the sensors and tricks that these systems can do, what is probably the most helpful? I know the accelerometers will give the g's and that will help explain a lot, but what about things like the wheel speed sensors, linear displacement sensors for suspension tuning, etc? Or, is it just better to stick to the basics and not get too deep into it? </font>

I think you can see from the postings above that the AIM (and the Action Digital) system both can deliver great value in the ability to do driver development. The low cost is obviously the first draw, but the software with the AIM system is pretty amazing (has features not found in some $5000+ systems), and it's updated free via the web. Of course, the software is one of the most critical components of any data system -- and the solid/professional feel of the Pi, Stack or MoTeC software can certainly contribute to how much you use/gain from the system.

I find the most useful sensor beyond wheelspeed/RPM/LatG is usually the throttle position. Next is a toss up between Steering and Brake Pressure.

The first thing I look at is usually the speed graph (which I always overlay with my fastest lap at that track), then I usually go to the section times report (a feature found on AIM, Pi, Stack, MoTeC), and look at the fastest rolling lap (this is the real measure of performance over the entire lap). On my Sports 2000, I have suspension position sensors, and I will study the front vs. rear roll to identify opportunities to improve the car with shock changes.

Do you need extra sensors? -- it all depends on what questoins you have -- I have lots of questions and have installed a bunch of sensors (latest was 12 IR sensors for real-time tire-temp measurements, I can now dialin the ideal camber for a critical corner on a particular course).

Regarding video: In addition to the CDS video system mentioned, Stack has a couple of products, once similar to the CDS just overlays text data values on the video stream. The other system called "Synchronized Video" is really powerful. You import your video into the computer along with the data, and it will show you the video on the same screen as your graphs. You can scroll through the video, and the data cursor will update, or move the data cursor, and the video will update. Really great for finding out that you were slow entering that corner because you were behind another car! It's a bit pricy, but totally unique in what it can do.

Please feel free to contact Veracity Racing Data, http://veracitydata.com if you need AIM parts/help, or just want to understand what the various systems available can do for you. Ellen is availalble at 408-732-6606, 9-6 most days.

[lateapex911]

I forgot to mention that AIM is coming out with modules that will atach to their MXL and MyChron systems for both video interface and GPS data.

I am not sure of eithers full capabilities, but the GPS module is said to offer full 3D track mapping.

David seems to have great input here, and I aould also recommend George at Motorsports Exchange. This guy calls you back before you finish your message! It seemed like no matter how many questions I asked he had full detailed answers.

If anyone will be at the ARRCs find me and I will be happy to give them the nickel tour. Look for my cars pic in the "ARRC spotters guide" here on IT.com

Too bad I'm such a newb at this...you won't get your nickels worth!

------------------
Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[924Guy]

I can also echo 110% the recommendation for George, he was truely awesome about getting me gear in time to upgrade for my impending race!

Likewise, as David was saying about the software... I can only speak to the AIM system, as it's all I've used for racing, but it's without question on par with the stuff we use at work to evaluate data from measurement systems (think data acq for development of production vehicle chassis control systems) which cost upwards of $25k.

------------------
Vaughan Scott
Detroit Region #280052
'79 924 #77 ITA/GTS1
www.vaughanscott.com

[Al Seim]

An update:

First, thanks to Greg Amy and Mark Coffin for their positive words about the DL1 GPS Data System.

Second, I'd like to give an update regarding the DL1 system and software. As David Ferguson correctly states, the software is a very important part of the equation. We now have a new major release (V5) of the DL1 analysis software (works with DL90s too) which has many detail improvements, including automatic "best theoretical lap" calculation. It also offers synchronized video!

The software (and sample data) is available from our website www.actdigital.com. Software, as usual, is free. The video feature does require a separate license after a 30 day trial period.

Feel free to e-mail or call with any questions.

Happy Holidays,

Al Seim
www.actdigital.com

[Scott Malbon]

The DL1 is on my Christmas wish list and I think Santa will deliver.

Scott

[Scott Malbon]

Does anyone have DL90 or DL1 files from VIR, CMP, or RR they are willing to share? I need to learn the software and these are the tracks I know best.

Thanks
Scott
[email protected]

[BillW]

Scott, I have some DL1 data from the 13hr race at VIR here:

http://bw.homeip.net/Bill/DL1/VIR.zip

Bill

[ITA Racer]

WOW. You guys are good salesmen. I think after reading this post I will be puting a data aqcuisition system on the top of my list. Seems like this will be the bets investment for a new guy. Thanks Dave