when i had an evo 1 last year id bought an ostrich 2.0 which allowed me to run launch control. its plumbed in to your ecu like a chip and had usb connections which allow different maps to be uploaded via laptop but disconnected when driving.
The site where i got all my info from was geekmapped.com, evo321.com, lancerregister.com.
i think the mitsubishi evo 1,2,3 run on 16 or 32 bit encrypted maps or something.
heres the site
http://www.moates.net/product_info.php?cPath=50&products_id=169if you want an aftermarket ecu eprom program that allows launch control look into this. im not to sure about coding but managed to upload a few maps before i sold up.
anyway hope someone gets there head round this i thought id share this in case it helps...