I come from an electrical engineering background and I like building things myself, so lately I've been toying with the idea of designing my own data logger and real time display for driving. However, I'm still learning my way around cars so I don't know what would be good variables to keep track of. I was thinking air temperature at the intake would be nice to know to keep an eye on heat saturation for a short ram intake. Possibly monitor the oxygen sensor or fuel mixture, if that would be of any use. I was also considering reading the fuel level gauge and display it on a scale of 0-100% instead of the normal dial. This would also allow for another feature calculating fuel economy for each trip. Basically I'm looking for information I could read off the car's sensors (or other sensors that could be installed) that would allow the driver to drive the car most efficiently or powerfully. Any suggestions?

Keep in mind I'm not looking to get anywhere near Hondalogger or anything like it. Just looking for a few things I could display on the dash board that would be useful to know for the sake of knowing or to better take advantage on the car's capabilities. Thanks for any ideas.

 

Coming from experience...

Anything you build is going to be harder than you think it will be to do.

Coming from a computer hardware background, I can tell you that real time display without so much lag that it becomes useless, while still doing the conversions needed to turn your raw voltage data into what you want to know, is a milestone in itself.

Data logging is a can of worms that companies with plenty of money to invest for years before getting any return on.

Now, assuming that doesn't scare you off. ALL you need to do for the fuel guage percentage stuff is to know your empty and full fuel gauge sender voltages and calculate the percentages accordingly, since the sender is just a linear potentiometer. But, if you want to get real accurate, you have to do some experimentation to find out what the voltage values are for known amounts of fuel from empty until full, because most tanks are not the same dimensions from top to bottom.

For the air intake sensor, you need to figure out what voltages correspond with what temperatures as well.

For fuel mixture, you need a wideband O2 sensor, because the stock O2 sensors don't have a fast/stable enough render time and signal resolution to give you anything useful otherwise.

To top it all off, data logging systems, and Dash race clusters are becoming more affordable, and commercially available.

If you want to do it as a hobby, I say go for it, but plan on it being a very involved and lengthy project that might last longer than you own your car.

 

Thanks for the informative reply. Sorry for the late response, I didn't realize anyone replied to this thread until now.

First off, I understand the complexity of what I want to do and that it'll be more work than I could imagine right now. However, I do have extensive experience with PIC chips and the Motorola 68HC12. I'm quite familar with all the A/D converting and calibration that would be required for this project.

Possibly the most useful thing to know would be the fuel/air mix from reading the O2 sensor. A wideband O2 sensor is more than I want to spend on this project so that rules it out. Is there any chance the stock O2 sensor signal could be convoluted the achieve stability at the sacrifice of some response time?

Thanks for any insight. Right now it's just an idea in my head. I don't know if I'll go through with it yet.

 

Well, if a wideband O2 sensor is outside of you budget, I'd hang it up right now.

A standard O2 sensor is too jumpy to get any real useful data at any time other than idle, or WOT.