This link may help you out.
http://www.brazosport.edu/~lshadoff/turbo/timer.html. And about your VAFC... It is sometimes alot easier and more reliable just to get a tuned ECU. Enjuku racing can tune it for you. It is called an RS Enthalpy tune. I've got an S14 SR20DET pushing 340 to the wheels with that tune so I know it works. Their shop is in Orlando, FL. Or just go to their website, Enjuku.com and tell them what mods you have. I hope I helped you a lil bit