hacking your car
This is something I've been looking into for a little while now and there's a lot to be said about it. I'm not sure if there are very many people that have done this but it's pretty awesome. Rather than buy a piggyback engine management system from Greddy for around 1,500, buying a stand alone engine management system from AEM for 2,500-5k, or flashing the factory ECU for a couple hundred each time you do it. The best choice that I've come across is "Mega Squirt". Mega Squirt is a "build-it-yourself" stand alone engine management system that sells for approximately 200 bucks!
You basically buy the circuit boards and hardware and do all the soldering and putting things together yourself. The software/firmware is freely downloadable from the site and there is a very large knowledge base there as well. This replaces your stock/factory ECU and totally gives you complete and unrestricted access to modify any and all settings! To include but not limited to: air/fuel ratio, boost, ignition settings, etc..
Although some of the software runs on windows, they do release the source code. There is no reason why this couldn't be compiled on a Linux/Unix system with a custom kernel. The ultimate solution I've been wanting for a while is to have a small computer mounted underneath the passenger seat that is directly connected to this so that I may change configuration settings at anytime. This computer could easily be hooked up to a touch screen in the middle of the console for easy access and operation. You could have this computer running everything from your sound system, your navigation, and still running as the interface to the mega squirt setup! If you wanted you could even have a pcmcia slot on the machine and have a verizon/sprint/whoever wireless aircard installed for consistent internet access.
Small things that may need to be addressed are:
If you don't read the docs and ask questions, mega squirt gives you almost too much control over what you can change and you can easily fuck up your car.
If you add a computer under your passenger seat you will need to look at proper cooling for this machine.
You may also want to add some kind of stabilizability control so that the machine is moving around underneath the seat getting bumped constantly.
More information can be found at:
http://www.bgsoflex.com/megasquirt.html
-cisc0ninja