Data Logger
 

Since there has been discussion lately regarding the Gtech pro.. I thought I might add this little tid bit of info.

I received in the mail today my DL-90 Race-Technology data logger. This is a GPS and two accelerometer based unit, with inputs for tach and 4 other inputs.

Since my race car is on blocks, I decided to test the logger in my truck. I installed the logger and GPS antenna in my truck and drove to the beach and back.

The accuracy of this unit is amazing, the map it drew for me when I processed the data was amazing. I could interpolate lane changes!!

Also the DL-90 comes in a Halliburton type attache case. I cant wait till spring and use this thing in my car.

Yes it costs more than the Gtech, but it is not a one dimensional unit.

Perhaps this logger will show me what a bad driver I am LOL

oh yea..... I got a .7G turn in my mountaineer

data-loggers are great tools to learn how consistant you drive on the track, remember consistancy is what makes good drivers stand above the rest :)
that should also have capabilities of adding laser temp sensors, these can come in handy for evaluating rotor surface temps/tire temps.
sounds like you're going to get to have alot of fun
:D

How much did you pay for your DL90?

I've seen them advertised for something like $650. Is this consistent with what you paid?

Thanks,

Brian

did you take the firestones off the mountaineer before that 0.7g turn?

I paid $655 with shipping

and yes the Firestones are long gone, (I took advantage of the recall program)

My '97 Mountaineer has 128000 miles currently, I think I am on my 4th set of rubber, and it pulls a trailer just fine.

This data logger is impresive though, the in car unit is about the size of a pack of cigarettes. ant the GPS antenna is about the same size.

Ive been playing with my "to the beach" run and finding out the capabilities of this unit. I think it will take a long time until I find all the capabilties of this unit..

Check out these guys if you are looking for a data logger:
http://www.race-technology.com
I have an AP-22 and while it doen't have the GPS capabilities, it sure is a good device for logging a few laps (it has longitudinal and lateral accelerometers) and then working on smoothness.

Bob......... Race-Technology makes the DL-90

Sounds cool. FYI, the G-Tech has 3 acellerometers, so it's three dimensional & measures side loads (I believe). I have mine in a box on the kitchen table - I need to test it tomorrow...

-Wayne

how good is your kitchen table going to handle wayne?
make sure you post the results :)

hmmm ok cough cough...

Wayne per the Gtech's website

At the heart of G-TECH/Pro is a precision 3-axis accelerometer, a sensor that measures acceleration also known as G-Force.

I read that as one accelerometer..

Im getting the hint that the GtechPro is on Pelicans bill of sale. Perhaps you should investigate the capabilities if the DL-90. It uses GPS (with a minimum of 3 satellites) and 2 accelerometers, along with the parameters you define to draw the track maps and provide the data for interpretation.

Lets compare notes if you like...... I am just amazed at how powerful a data gathering device the DL-90 is...... I will be learning all the cpabilities this winter by testing it with my truck..before I take it out on my race car this coming spring.

the DL-90 is a killer piece, i think waynes point was the g-tec pro has some basic affordable datalogging capabilities at a much lower cost.....but we all know we get what we pay for.

There seems to be some confusion here about which G-Tech Pro version is being referred to. The latest version Wayne was referring to, and the only one with data logging capabilities, is actually called the G-Tech Pro Competition model, and it DEFINITELY has 3 acellerometers total, one on all three axes! The earlier version that is several years old, now, had only one acellerometer, and was intended primarily for drag-racing enthusiasts.

I attempted to call G-Tech but couldn't get past the basic sales guys who weren't very helpful.

In order for the GTPComp to work for road race use is recording time and sampling rate. If you can record 15-30 minutes on the meter, or hook it up to an external recording device for real-time download of this data, then it could be a great analysis tool.

I think one of the aftermarket software tools could infer a track map using the speed and accel data.

TimT,

Any word about this device yet? The website listed it as $499 pounds which is almost $800US now.. Where did you get it for $650US?

The price may have gone up since they got a nice write-up in the latest issue of RaceTech. I haven't had time to read it yet, but it's on the newstands now.

Chris,

I ordered the DL-90 directly from race-technology. It was shipped to me from cb racing . Race-technology didmention on their website that the $650 price was an introductory price good till the end of 2002 (cb racing still lists the DL-90 at $650), but D2 Engineering now lists the DL 90 at $800.

I have played around with the unit in my daily driver and am really amazed at the accuracy it records to. For example I did some laps of a large parking lot near me, and varied the line incrementaly, (changing radius and diameter of turns). When I used the "overlay lap" function it actually showed the variances in line. I did my laps at speed less than 40 mph in my mountaineer so it was really easy to be consitent with the line and the changes were controlled.


ramble mode off

Also check the D2 schedule, they will be at gingerman in april with DL-90 rentals. (you do run gingerman?)

Do the DL-90 people site an accuracy? I thought that non-military GPS were only close to within a yard or two.

I think the accuracy restrictions were removed a few years ago.

Maybe we can measure to a few feet with a GPS and the military can measure to the inch now

THe website says that standard commercial accuracy is only 15meters... That;s like 45 feet! I think it's better than that, and what really matters in this case is resolution from point to point which supposedly is a lot higher...

Well Tim, guess what the wife just ordered me for my birthday?

Woohoo!

Cool for you Chris.....does your wife have a sister that is single?

my ex just didnt understand... I told her its all adrenalin and endorphins...


one thing that is amazing about the DL-90 is that when you go for out a run you just hit the "sample" button and it will record data until you hit "sample" again

It records about 90 mins of data

Then you dump all your runs into your laptop and have some brews and analyze

What sort of cable does it output through. I'd get it, but I'm on a Mac, and would have to either go buy a PC laptop for this one thing, or find a way to get the data into the Mac laptop, and then run a PC emulation program. Anyone ever taken a stab at this?

Jack the output is by serial cable (RS 232) Macs still use that dont they?

The software is windows based though

They can fake being Windows machines just fine, but their ports are all USB and Firewire now.

WTF?
Ok
Jack you go figure it out, the DL-90 has a serial output. I have heard thats a pretty universal method of data transfer ( slow perhaps)

Jack,

They make USB to serial adapters...

I'm just starting to play around with the software from their website....

Esther is the patron saint of race car wives...

I think the accuracy comes from the computer interpolating/reconciling data from the GPS and accelerometers.

I just ordered one.

(But I still want something that will show speed/brake/throttle on my lap videos.)

You just ordered a DL-90? Like just now? :)

Have you played with the Software yet?

It certainly is in it's infancy, but you can get some nice analysis out of it. It takes some work, but it's there... They will be getting a LOT of feedback from me... the poor ba$tard$. I've been working in software for 15 years so I know the biz...

I'm fooling around with the lastest version now... It's improved but still somewhat unstable.

Tim, how much time have you spent on the software yet? I can't find an easy way to overlay speed and g-forces in a corner for several laps... Have you?

(I'm beginning to wonder if I have to break out the programming manuals again, Yikes!)

Yes, I ordered it. I'm not married to Esther, and I don't want to be faced with the new, higher price later.

And I'd like to possibly use some of its sensors for the digital lap video display we've been talking about in the other thread.

My car is out for weeks, still, so I'll wait for the Streit-ified version software, if need be. ;)

Ideally, you'd be able to make it generate something like this:

http://opentrackracing.com/kevin/cortlap.jpg

Jack...

Here's an example that's similar. You can define your own transition points. Those points can be measured in a graph or spreadsheet later. The color shows the acceleration or decelleration... You can also have it show Yellow vs. black for braking vs. accellerating to analyze braking points....

THe thing that is difficult for me to far is comparison lap to lap...

http://forums.pelicanparts.com/uploads/DL90TM1.JPG

Here;s an example where you can see (in black) when the driver releases the brakes, and that he is doing some trail braking.

In your case you could easily tap into the throttle position sensor and hook it up to the analog input...

Oh... One advantageous thing... If you do a screen record of the output of the track map replay, you could syncronize it with a video-editor to your in-car video... THen you could play a movie with the video, and with the acceleration/brake dashboard and track map right next to the actual in-car video, producing a double width video.. That would get you what you want in the end...

http://forums.pelicanparts.com/uploads/DLTM2.jpg

crap....you guys suck! Now I have another toy I absolutely must have, the wife is never going to forgive you. Ha Ha...thanks for the info and the graphic display capability. Even though I will not be running the big track events, this would really help me get better at the local autox and then maybe one day I will brave the track!

K9... Sorry dude... But it IS really neat huh? :D


In this case you can see that (for WHATEVER reason) The speed at the exit of turn 1 does not dictate the speed at the entrance for turn two (before braking). I would guess that this could mean the driver is lifting early (which could be determined by the TPS)... Strange this...

http://forums.pelicanparts.com/uploads/DL90TM3.jpg

Jack, I have a G4 laptop running OSX with Virtual PC 5. I run a few high end CAD programs on it with no problems. You should have no problem running this software on it. The only snag is the serial port. I have had problems in the past with Virtual PC seeing serial connections. Why they still use serial is beyond me, they should also include a 5" floppy to install the drivers....

Jack... Here is one... Just wanted to follow up with you to make sure I was on the level with that one...

http://catalog.belkin.com/IWCatProductPage.process?Merchant_Id=1&Product_Id= 102007

this is just really cool stuff...add this DL-90 with the accelerator and brake indicator lights (like Jack is looking into) and you can post some pretty cool "lessons learned" videos and even handouts if needed!

Okay, with something like this Jack you'd be set...

http://forums.pelicanparts.com/uploads/dl90sc2.jpg

Chris,

Is there a good story behind that litte black squiggle coming off of the hairpin in your first track map ?

And of course I'm asking because I wonder if the DL-90 can help you determine the cause.... ;)

From the looks of the data run, I think it's a pit area or some such thing... You can see the car driving through it slowly...

I dunno, this is just some sample data, not actually mine...