Data Logger

[Jack Olsen]

Hey, that's Thunderhill in the last example.

Yeah, I think the two ideas complement each other. To me, watching the videos is a great way to visually reinforce the lessons learned. The stuff offered by the DL-90 is useful in a different way.

We'll have to see if the DL-90 can communicate with an emulating Mac. I've got an older G3 laptop somewhere around here that still has that kind of port on it, I think. If not, I'd imagine I could pick up a slightly-out-of-date PC laptop for not too much, and just use it to run this one app.

[930fan]

I have been trying to find a website for the manufacturer of the Datacam. It isn't as sophisticated as some of the stuff on this thread but I think it is a good low cost alternative for the non-pro track enthusiast.

[cstreit]

Jack,

Low end laptops such as the one I will likely use, can be had for less than $150 all over the place on e-bay.

I have an old pentium 75 (8 years old) that I will use... No fear of breaking it since it will see hard duty at the track...


930FAN : It's

http://datacam2.com/

[Jack Olsen]

Datacam is expensive. The basic, non-upgradable unit is $500. If you want to add bells and whistles, it gets close to $1500 pretty easily.

[930fan]

Thanks for the website guys. I take it you are not fans of the product.

[Jack Olsen]

Low cost alternative? As I see it, the Datacam is at least as expensive as the DL-90, and depending on how you configure the Datacam, it can easily cost double the DL-90, for less functionality.

I think adding speed, brake, and accel indicators to in-car videos is a great idea, though -- so good, that me and another Pelicanite are building one ourselves. Having the numbers appear like close captioning is great in the Datacam setup, but it also requires a separate camera and recording deck, which further adds to the expense. I think a dash-mounted illuminated LED display would be just as good, and maybe 1/50th the cost.

But a data display like Datacam's is very different from a true data logging system, like the DL-90, in that with the Datacam you can't play with the data on a computer, and overlay multiple laps, and get specific braking and accelerating points that you can graph and compare.

They're two different animals, each useful in their own way. (I plan on getting both.)

[cstreit]

I think with some practice you could meld your in-car video with the output from the DL-90 and get the same result... THe only difficult part is syncronizing the video tape with the output of the DL-90 software.

THis also requires that you download the video into you computer to do the editing..

I dunno, I'd like to have both, but the datacam would be more for fun than improvement...

[TimT]

I can't find an easy way to overlay speed and g-forces in a corner for several laps...

Chris the way to get lap by lap comparisons of speed and gforce is to graph speed vs time and G's vs time on the same graph. You can then "play" the runs and toggle between the track map and graph. You can also do lateral g vs long g's and make the friction circle.

Also Chris turn on the g force vector on the track map, this shows the instant you tap the brakes.Youcould add the track markers at these points and analyze entry speeds, conversly you could do that for corner exit speeds also.in

I just noticed that the they already have a newer version of the software available. ill have to install that

Jack, I see you took the plunge and bought a DL-90 the logger has analog and digital inputs, so you will be able to see your braking and throttle info. If you split the signals from the TPS and brake lights you will be able to work some thing up to fire some lights on your dash. I think those mini auto-meter shift lights would work pretty well

[cstreit]

Thanks Tim...

I figured out how to run the same car, same run, but 5 different laps simultanteously on both the map and the graph. Thing You don't need to use the G-meter to see the brakeing zone, you can highlight it on the track map show it shows the trak in black when you are braking, and yellow when you are not... It's really cool!

[TimT]

Chris I think i saw you post that your going to use a 75hz laptop to crunch the data. I think you will be waiting a long long long time for your results. I have a 330 hz laptop and it takes quite awhile to compile the data. the playback on the slower machines it choppy to.

The Dl-90 is easily mounted and dismounted, I just took the unit out of the car, to my main computer and used (the supplied) 12v converter and the spare serial cable i leave plugged into my main pc to download the data.

I just though of another way you could analyzecorner dynamics on different laps. You can save the files as *.csv file then use excel to manipulate the data. I havent tried it but it is an option. Im scrambling now to get my car ready for some events in late march

[cstreit]

Hmm... Hadn't thought of that... In fact I hadn't tried it on that laptop yet, so I went ahead and did it... DOesn't even have enough RAM to run the thing...

Soooo.... I have another multi-Ghz screamer to use, was just hoping not to take that one to the track... Maybe ebay..

I tried the CSV thing, if you use any kind of decent sample rate, the data volume in Excel is staggering....