Affordable data logging?

[djmcmath]

Some of the recent discussions have made me think: wouldn't it be fantastic to have a computer doing data logging during track runs? You could connect manometers to read airflow information, or thermocouples to track temps. Some kind of DME hookup would be essential, so you'd have throttle and RPM inputs. For example, for Jack's aero mods, having a dozen or so thermocouples scattered through the engine bay would give invaluable data as to whether or not the mods were helping. Brake duct changes, or pad/rotor changes would be similar -- having a TC on each caliper could make all the difference in the world, knowledge-wise. Heck, just having the throttle/RPM/speed data would be great for analyzing the mistakes in a lap.

So is it possible? Is there any reasonably affordable way to pipe analog sensor data into a digital laptop (or similar) for this kind of purpose?

TIA,

Dan

[SPJ-911]

Not sure what your idea of affordable is but check out the link below. When you start talking extensive analog inputs the cost of the system goes up pretty quick. If you are familiar with National Instruments you can get a board to install in a laptop and attach sensors to it. I am a test engineer and use Somat eDAQs which are the best out there, but you don't even want to know how much they cost. The device below can be had for around $3K.

http://www.motec.com.au/adl.htm

[kjb]

Dan,

If you already have a laptop and some programming skills, you should be set. There are companies making fairly inexpensive multi-channel A/D converters that plug into the USB port.

I don't think you'll get throttle position from the carrera DME. There's a sensor that tells you if the throttle is completely closed, and one that tells you if it's wide open.

You should be able to pick-up RPM from the cigarette lighter jack. There's probably some A/C ripple that you can get the frequency from and calculate RPM.

You'll most likely have to make some simple electronics to convert you signal into a voltage within the range of your a/d converter. If I remember correctly, you can read about how the Carrera AFM is hooked up in the Bentley manual.

I think this would be a fun little project too. I don't track my car, but it's still struck my mind that it would be fun to put something together.

/ J

[Early_S_Man]

For low-cost DAQ, check out the Measurement Computing USB products ... $109 - $399, depending on resolution and sample rate:

http://www.measurementcomputing.com/usb.html

[kstylianos]

http://www.apexvisualizations.com/

They use a DL90 to record the following:

High quality video and audio
A track map with real-time car position
Engine speed in RPM
Car speed in MPH
Braking and Acceleration
Lateral G-forces
Current lap time
Best lap time for the session

Probably can ask them to help out with your specific request.

[jpnovak]

Charlie is right the race technologies systems(DL90 and others) work well. They also have external analog inputs to track additional information. It would be a matter of finding the right sensor, ID the signal, feed into the logger. These systems have a serial port to download into a Laptop.

http://www.race-technology.com/WebPage2/Products/DL1/DL1Home.html

One the board members owns ApexVis and allows the information to be fed into a video camera as a text on the bottom of the screen instead of the laptop. This allows for real time visual logging such as cornering force. It even allows you to download a track layout and analyze specific sections. Very cool setup. I am saving my money.

You would be building a highly integrated system. sounds like fun.

[djmcmath]

The DL-90 setup, complete with GPS, looks a lot like a really excellent driving analysis tool. Given that seat-time is the #1 most important thing to improve speed, it seems like $1000 worth of track-data-logging would be a pretty good investment. It'd be fun to couple something like the DL-90 with one of the tools from Warren's link (measurement computing) for detailed data about engine/brake/airflow-type data.

Affordable, when I first posted this, was like a few hundred $$. It doesn't look like that's terribly practical -- perhaps under $1000 is a more reasonable goal. (sigh) Time to start saving pennies.

For throttle position, I was actually thinking something more like MAF sensor position -- that'd give an idea, right? RPM and speed should already be electrical signals -- the sort of thing that vary resistance based on speed, no? Tapping into the chassis electrical to measure frequency would be an difficult and error prone technique, it seems; there ought to be a more straightforward way to obtain that data via the tachometer. ???

Dan

[Grady Clay]

Data logging can be as complete or inexpensive as you want – your budget will determine that.

Some places to look:
http://www.veracitydata.com/
http://www.corsa-inst.com/
http://www.piresearch.com/
http://www.advantagemotorsports.com/
http://www.competitiondata.com/
http://www.truechoice.com/menu.asp
http://www.maxqdata.com/

For a skilled tech, this is basic easy stuff. An off-the-shelf system is as inexpensive as you want and is very functional. For complex and custom systems, there are a large number of (probably unemployed or under employed) experts. Many will advise for little or no compensation just to keep up to date with the technology.

Best,
Grady

[Randy Webb]

I use Campbell Scientific dataloggers. Gaylon Campbell was on my PhD committee - they are a lot bigger now. These are designed for environmental use - but car co.s are a big customer for them. They are rel. slow, very high res. (nV range) and totally bombproof (literally). Prices start at about $1k. They are specifically designed to measure wind, temperature, etc. and have lots of pre-set programs to excite various sensors such as phtochoppers for wind, etc.

So my choice is somewhat historical. I have one in the basement bedroom right now checking on the temps. of the wine in there....