cetom

so i finally figured out the problem . the remote usb cord was shorting out the system . i removed this and all is good . thanks all and thanks amso3

cetom

jerry was kind enough to help and so the AIM unit is up and running. thanks
may i ask for some additional help. i have a motec MADXL3 , which is a three axis accelerometer. there is a wire coming out of it that i have not opened up yet . i am guessing or hoping that there are 3 pair of wires ,one for each axis .the wire terminates in what i think is a custom 6 pin female connector.
anyway, i would like to use this sensor as part of my AIM PISTA unit.so once i get the wires sorted out should i just attach them to like channel 2,3 and 4 and use them as generic linear 0-5v potentiometers
thank you and have a great holiday

Matt Romanowski

You're plan should be ok. What brand accelerometer? You will probably have 5 wires out: voltage in, ground, then x reading, y reading, and z reading. You will only have to power from one channel and will need to know if it's 5 or 12 volts (or doesn't care). Should be pretty easy.

amso3

Ron

I found this schematic on the Motec website. You do not need to connect all three accelerometers, you have a Lat Acc in the dash, you don't need a Vert Acc so you only need to wire the Longitudinal ACC. I've also attached the wiring color chart for the AIM Pista channel extensions. I'd cut the end off an AIM extension and verify that the Blue wire is 5V before you connect. You can verify it's function by going on-line and turning the accelerometer 90 degrees (before you mount it. It should go from 0 to 1 G as you rotate.

Matt Romanowski

I would still hook up all three directions. It would be interesting if you mount the 3 axis sensor right at the Cg to compare it to the lat G in the dash. Also, with the vertical G you can do some math to figure out percent of traction used.

cetom

thank you very much for the above . i will get the work done this weekend .
when i get it all connected doi calibrate the acelerometer automatically with the aim unit or do i have to build a special sensor table. i know these questions are rudimentary but i had someone else do the work initially and so this is my first time with an installation
is there there some standard or accepted way of knowing where the cg is
thanks

Matt Romanowski

Looking further, you will only be able to use the vertical and horizontal accelerometers. In the channel setup, you'll select longitudinal and vertical accelerometers. They don't have an option for the lateral one because there is on in the dash. If you build a custom sensor, it won't let you calibrate it how you need to.

As for finding the CG, check out http://www.how-to-build-hotrods.com/...f-gravity.html

amso3

Ron

Porsche mounts the accelerometer in the center of the car on the tunnel, behind the driver seat where the rear seat cushion would start. That should be adequate.

cetom

thanks. we are doing the intall today or monday. its funny how quickly the tunnel gets filled up with stuff. i also use a 4 camera raceeeper unit and we plan on also mounting it on the tunnel .
i understand now (i think) how to attach the acceleromter to the aim. the aim unit itself has the lat accel. within the channel choices there is vertical and horizontal acccel. horizontal will become" longitude".
sometimes i have to remind myself that getting good at setting up and understanding data isn't the goal . the goal is driving fast consistently.

ProCoach