My plans

Working:
Ogg Vorbis / MP3 player

Need help:

Lm_sensors to monitor air temperatures like air inside car, air under the hood, air entering engine, and engine temperature. Or monitor fan speeds like the speed of the radiator fan.

Linux GPS system. (Is this one practical?)

Hardware:

Have:
dual 866 box with 256ram
car power supply unit

Not sure where to get:

Linux supported fan speed sensors
Linux supported heat sensors

Temperature probes wouldn't be much of a problem, as I've seen USB probes used within scientific research that would do the job, but I doubt you'd be using lm_sensors, as they're just picking up sensors on various motherboards + voltages / fan speeds of the board. Not quite sure what you would use, but it would probably be a case or reading the value of the probe to a file, then using whatever front-end to read them all in. As for fan speeds on radiators and such, really doubt you could do that into a Linux box - haven't seen anything that would read it in, as there's no easy way of connecting in to the car's electrical systems to get that kind of data, not without voiding any warranty from your car dealer. When lm_sensors reads in fan speeds, it's just picking up the eletrical signals from your 3 pin motherboard connectors, but it's a bit different with your car radiator.

Why (other than because you can) would you want all this data anyway? Can't see any real use for knowing the temperature under the bonnet or exact engine temperature (and what part of the engine exactly?). But, good luck if you want to give it a go!

some of these things you said could be done with sensors already on a motherboard, but I don't think it would have anything to do with linux, just the BIOS. Like if you were to look in your BIOS right now, you'd find temperature of your CPU and some fan speeds... Othere than that, I think the last guy was right, check out if there's anything as far as hardware available 4 measuring scientific stuff. There are a few "scientific" aimed distros, but I have no idea where you can get hooked up with linux science peoples.

Good luck, it sounds very cool,

slackwarebilly

The car is a 1990 Mustang project car so warranty is not an issue I have replaced the radiator fan with a large three wire electrical fan. I can run the yellow wire to the motherboard but not sure if it will read fan speeds that high. Where can I get USB probes?

Okay, if it will plug into the motherboard, fine, it should read the current fan speed the same way any fan will. Whether I'd want to have my car radiator fan running through a PC I'm not sure! But, that should be picked up fine by lm_sensors when configured correctly for you motherboard. A quick google for "usb temperature sensors" brings up a number of results. Have a look and see if any of the data loggers are compatible with linux.

Check out these two sites...

mp3car
ryanspc

Linux thermometer project:

http://www.joepverhaeg.nl/ltp/

GPS navigation software for Linux:

http://gpsdrive.kraftvoll.at/