Yes I'm using the seat-of-the-pantsometer. I try to use as less money as possible. There are some indications on running rich other than black smoke out of tail pipe. Sparkplug conditions, too much fuel will create backfiring on exhaust pipe. Air/fuel ratio gauge readings. Yes I know the gauge is not that precise, but it give you an idea. Remember I'm running stock injectors plus 330cc. That is a lot of fuel. Better to run rich than lean. Everybody know the symtoms of running lean, so I try to run very very rich first then start leaning out little by little. Right now the next step-up in the setting will rich me too much.

If you are running more than 23psi, don't get it. Or if you have 900.00 for the new version HKS AIC-3, you can boost more than 23psi. Also it give you an obtion to use high or low impendace injectors.

No, didn't spend money. That is the beauty of custom setup. Better if you do-it-yourself.