Tell me about your DL-90 Data Logger

[jpachard]

I know a few of you must have one of these. How do you like it? It looks like a very comprehensive package. Did it help your driving? How do you like the software? Thanks in advance for the help.

Cheers, James

[carnut169]

Look into AIM's systems also. For the $$ they are very sweet.

[jpachard]

AIM!!??..Please don't tell me you're instant messaging while on the track :-) Seriously, What is AIM, Iss there a website?

Cheers, James

[jluetjen]

Hi James. Here's some more references off of the Production Racing Forum. I know that one of the guys here on Pelican is also working on integrating video since he posted a trial version here earlier.

[cstreit]

James...

It does everything they say it does!

BUT.. (and this is a BIG BUT) you must take the time to analyze the data to get value out of it, AND have the time to try different things on the track to see what works.

May favorite use is to find those 1 or 2 corners on the track where you are loosing the most time, and try several different lines through it in a session. Then go back and look to see a) which got you through in the least amount of time and b) what your time was in the next session to make sure your exit was the most optimal as well.

For instance in a "throw-away corner" you don't look at the corner so much as the time you were in the following straight. Then go back and find out what line was best..

[304065]

James,

Chris gives (as ever) good advice, I'd add to it the following:

1. Initially the DL-90 is like trying to take a drink out of a fire hose. There is a ton of data and the interface takes a few hours to get comfortable with, so I find that I understand it better when I break the track down into discrete segments.

2. Once you have a) a consistent line in practice; b) good data on the car, e.g. you know the caster, camber, toe and other alignment settings and c) tire data = pressures and pyrometer readings, you can then begin to exploit the DL-90.

3. What Chris said is exactly right-- you only want to change ONE THING at a time. Car is understeering in slow corners. Reduce front tire pressure by one pound. Go out and run three laps with the DL-90 set up, then immediately come back, drop the tire pressure by another pound, go do three more laps. Once you get done with the session, you can then analyze things like the maximum speed through that corner, the segment time, the max lat g, the max long g, etc. It gives you quantitative feedback on the effect of changes to setup. But the only way to effectively correlate speed vs. changes is by only changing one variable at a time.

Which takes a long, long time. Sometimes I wish our sessions weren't 20 minutes long, but rather 7 minutes, so you could do a whole bunch of separate sessions with a tuning/analyzing period in between.

I love mine, every time I use it I say, "There is no performance, without measurement!"

[NicolasW]

No experience with it....but a local club member started a company this past fall to merge DL-90 data with your video camera to look at your driving style.

Check out http://www.apexvisualizations.com/

[jpachard]

Men,
Thanks for the responses. I feel that right now I really need to analyse different sections of track to see where I need to improve. Right now all I have is a laptimer which is great but has it's limitations. I know the DL-90 has a ton of info on it so I guess it's pretty user friendly? Right now every track I go to I turn laps off within 1 sec of each other, they just need to be faster. My gut feeling is that on any given lap, I do a few corners well and a few not so well. It would be really helpful for me to be able to see what's working and what's not. Thanks again for the help. Also, how's the reliability etc Can I convert serial to USB signal? I have a laptop with no serial but USB?

Cheers, James

[304065]

USB/Serial convertor is about $30, check www.pricewatch.com

[rs911t]

know that one of the guys here on Pelican is also working on integrating video since he posted a trial version here earlier.

That's be me! Thanks for the plug. Check out the web site for more details. I'll have a new beta release available in a couple days.

[TimT]

The DL90 is a really powerful tool... couple it with the apexviz software and its even more usefull...

usb/serial converters can be had for much less than $30

[rs911t]

Can I convert serial to USB signal? I have a laptop with no serial but USB?

I've tried to connect my DL90s to a laptop via a serial-to-usb adapter, without any luck. Any of you make this work? I'm just a software geek ...

[304065]

How many of the external interfaces have you guys hooked up? I would be interested to know how you wired the data acquisition for the DL-90.

RPM
Wheel Speed Input
Digital input (brake on/off)
Analog Input (oil pressure?)
Analog Input (oil temperature?)

I'm gonna get some lightweight Tefzel wire and hook it up, would love to know how you guys did it. Chris?

[jpachard]

John, have you tried the USB converter? It seems like there are conflicting reports in regard to this working.

Cheers, James

[cstreit]

I have:

1. RPM (standard)
2. GPS (standard)
3. Ignition Advance from twin electromotive units (into analog)
4. Brake (into digital)

[Jack Olsen]

Where are you guys mounting the unit in the car?

[304065]

I have had success duct-taping it to the top of the dash with a piece of folded-over duct tape under the aft edge to level it out. Also success taping to the passenger floor. Since I don't have a radio I'm going to fab an aluminum plate the same size as the radio grill and mount it on there, with some washers underneath to level it out.

Chris, how do you wire RPM pickup?

James, I haven't used the USB/Serial as I have serial on my old track laptop. Presumably it would have to include a driver to spoof the software into thinking that the USB bitstream was coming from the serial port.

[cstreit]

Mine is mounted to the cross-brace on the roll cage.

John, I just used the inductive pickup that they send along with it. I figured you could tap off the RPM wire, but it doesn't work for some reason.

[Jack Olsen]

Originally posted by john_cramer
Since I don't have a radio I'm going to fab an aluminum plate the same size as the radio grill and mount it on there, with some washers underneath to level it out.

Ah! Smart. That's what I'll shoot for.

[rs911t]

Where are you guys mounting the unit in the car?

I cut a aluminum plate about 8" long and tapped it to thread onto a tripod or camera mount (1/4" x 20) then plastered it, the DL90, GPS receiver and lipstick camera with velcro. The plate can be mounted to the rollbar with an I/O port or a tilt-and-pan tripod head (done both with good results). The camcoder sits on the floor.