http://www.toysport.com/technical%20information/22r_tech_notes.htmTheres where I get my info from. I dont know much other than that. Besides what others have posted. On mine I cleaned up the efi unit black stuff in there, took out the catalyic convertor, and just ran a glasspack, got the tuning right, along with the distrubter right, and changed the spark plugs to high quailty ones.
Obivolusly I havent done what others have, and it seems like great power to me.
Also check out wildyoats.com for more mods.