Track-Day Data Systems

[Rick F.]

I know that a number of you participate in track days around the country—as well you should, given your capable car! I also know that there are a lot of data systems out there, ranging from iPhone app's to very comprehensive units that put to shame those available to professional racing teams as recently as the 1990s.

Back when I was racing a Sports Renault / Spec Racer with the Sports Car Club of America, Mike Valentine had just come out with a data logger called a g-Analyst. This was right after he'd been forced out of the radar-detector company he helped found (Escort Inc.) and before he'd created his groundbreaking Valentine 1 detector. The class rules didn't allow us to use a g-Analyst in SCCA races, but it was okay in practice and qualifying. I bought one and found that a careful review of the data showed a number of areas where I could improve my race driving.


One difficulty with such systems involves how to interpret the data. Data loggers produce thousands and thousands of measurements. Even with good software to view the results, what should you be looking for?

With that question in mind, I thought that some of you might enjoy reading an article that I wrote for Porsche Panorama some years ago. It focuses on interpreting g-Analyst results, but the same principles should still apply with newer systems.

See what you think--I hope it's useful. It's available at Porsche Panorama article.

Also, what modern systems are you guys using? I'll likely be taking my roadster to some BMWCCA track days this year, and I'd love to capture g force data.

Rick F.

[SD ///M4]

Originally Posted by Rick F.

Also, what modern systems are you guys using?

I'll likely be taking my roadster to some BMWCCA track days this year, and I'd love to capture g force data.

Great timing on this question! On May 22 my local BMW CCA Chapter is putting on a join Tech Session with the local PCA chapter at a local independent shop. The topic is

Tech Session - Track Data Acquisition Systems.
This Tech Session will provide an overview of available Data Acquisition systems and software to include advantages of using track data acquisition systems, smart phone software, data loggers, creating video overlays, and basic data analysis."

The person who is speaking at this event is an avid BMW autocross and track junkie and has a highly modified 135i. He consistently takes first in his class at our autocrosses and posts his videos on YouTube, complete with all of the data displays. He is probably the most knowledgeable member in our club when it comes to data acquisition.

I'll be sure to take lots of notes and report back what I learn!

As far as taking your Roadster to some BMW CCA track days this year, my understanding is that BMW CCA does not allow any open top cars to run unless they have a full roll cage.

[MFGJR]

Originally Posted by Rick F.

I
Also, what modern systems are you guys using? I'll likely be taking my roadster to some BMWCCA track days this year, and I'd love to capture g force data.

What I'm using: http://www.zpost.com/forums/showthread.php?t=610564

Trailbrake.net has some useful basics, and there's a good bit of useful stuff to be found on youtube.

[3002 tii]

Correct CCA won't allow your roadster but you can drive with PCA or NASA at the very least. I'm using Harry's Lap Timer software for the iPhone.

[Finnegan]

I'm also using Harry's Lap Timer, with external GPS and OBDII connections (Bluetooth). DSC's thread over here has some more info.

For the price, if you have an iPhone 4 or better, it's a pretty good deal. The externals simply add more data inputs/parameters. It's going to capture Gforce data--the question is whether it's capturing it with enough frequency to satisfy your analytical needs.

If not, there are other good systems out there, and SD Z4MR should be able to get some good info for us on those.

[Rick F.]

Originally Posted by SD Z4MR

Great timing on this question! On May 22 my local BMW CCA Chapter is putting on a join Tech Session with the local PCA chapter at a local independent shop. The topic is

Tech Session - Track Data Acquisition Systems.
This Tech Session will provide an overview of available Data Acquisition systems and software to include advantages of using track data acquisition systems, smart phone software, data loggers, creating video overlays, and basic data analysis."

The person who is speaking at this event is an avid BMW autocross and track junkie and has a highly modified 135i. He consistently takes first in his class at our autocrosses and posts his videos on YouTube, complete with all of the data displays. He is probably the most knowledgeable member in our club when it comes to data acquisition.

I'll be sure to take lots of notes and report back what I learn!

As far as taking your Roadster to some BMW CCA track days this year, my understanding is that BMW CCA does not allow any open top cars to run unless they have a full roll cage.

SD Z4MR,

Should be a very valuable tech session. I learned a lot during my SCCA years from the g-Analyst.

Thanks for the head's-up regarding BMWCCA and open cars. Years ago, I was the chief instructor for the DC chapter of BMWCCA, but the rules have changed since those days--and probably for the better.

Rick F.

[Rick F.]

Originally Posted by MFGJR

What I'm using: http://www.zpost.com/forums/showthread.php?t=610564

Trailbrake.net has some useful basics, and there's a good bit of useful stuff to be found on youtube.

MFGJR,

Wow, technology has come a long way! The basic g-g data from your system is very comparable to the g-Analyst, but the ability to import speed, rpm, and other inputs from the car is impressive, as is the data overlay on video.

Thanks for the response (and for the detailed DIY instructions in your other post).

Rick F.

[Rick F.]

Originally Posted by DSC_OFF

Correct CCA won't allow your roadster but you can drive with PCA or NASA at the very least. I'm using Harry's Lap Timer software for the iPhone.

DSC_OFF,

Thanks for the suggestions re PCA and NASA. And regarding Harry's Lap Timer, which also looks very comprehensive. My jaw is dropping even further at the state of technology...

Rick F.

[Rick F.]

Originally Posted by Finnegan

I'm also using Harry's Lap Timer, with external GPS and OBDII connections (Bluetooth). DSC's thread over here has some more info.

For the price, if you have an iPhone 4 or better, it's a pretty good deal. The externals simply add more data inputs/parameters. It's going to capture Gforce data--the question is whether it's capturing it with enough frequency to satisfy your analytical needs.

If not, there are other good systems out there, and SD Z4MR should be able to get some good info for us on those.

Finn,

Greetings! With Harry's Lap Timer, are you capturing g forces through a direct measurement or does the software calculate them based on the GPS data? Just curious; it seems like either way would be doable. Was the OBD II connection easy to manage?

Rick

[Finnegan]

As I understand it Harry's LapTimer uses the internal G meter on the iPhone to calculate GForce. Harry acknowledges that that's not optimal, but I bet he's going to upgrade it the future somehow. It does give a fairly good idea of Gs. I have the traction circle set to .9 as yellow and 1.0 as red.

Speed calculated by external GPS gives a lot of data points. The OBDII connection and external GPS using Bluetooth are pretty easy to integrate. I think the "Kiwiwifi", which uses wifi not Bluetooth, for OBDII has a higher data rate but I have no experience with it.