The alcohol becomes part of your fuel system. As the boost level rises, you increase the delivery into the motor. This keeps the transition seemless.
As the delivery increases you reduce the amount of fuel your injectors are delivering and let the alcohol make up the rest.
Up the alky, drop the fueling... back and forth. If you can get a pretty healthy flow of alcohol into the motor, the sky is the limit on boost/timing levels you wish to run.
Your starting point on timing, is what your street timing is. Your turnon point generally is dependant on style of system used. With my setup, I recommend a low turnon like 4 PSI.
How much are you adding..You keep increasing knobs on the controller... and watch your AF activity. Then adjust fueling to bring things back in line. Always tune with the car going rich then leaning out to correct.
On an S/C car.. you have a limit on boost. Once your at this limit.. start adding timing. If you encounter "knock" then add alcohol to eliminate the knock. Adding alcohol.. then you go and reduce the fueling some more.
Some of this is like riding a bicycle. Its very hard to tell you how to do it.. beyond placing feet on pedals and getting your balance..
Its not difficult, there is no majic, you'll be amazed how easy... once you start.
The above post is assumming your using one of my systems. If you plan on doing a DIY, then the strategy changes. Since varying amounts can only come from adding nozzles in stages via pressure switches, varying nozzle sizes, varying voltage to pump, etc..
