Re:how to run 14-15 psi of boost?
 

The 8 bit math is not a limitation of the microcontroller, it's a limitation in the fuel interpolation routine. If one were inclined to do so, one could theorectically rewrite the interpolation routine to use a 16-bit math function, and expand the tables. However, the MAP signal routine would also have to be altered in order to take advantage of these expanded tables.

Re:how to run 14-15 psi of boost?
 

maybe ill try jan style :P 15psi, afc hack, stock map sensor!