Originally Posted by Chip

Depends on the chip, as you are adding extra fuel on the nitrous kit anyway so in theory it should be fine without changing the map, especially if you are able to retard the timing a little with the octane wires to keep that safe too.

The only issue you might have is if you spool the turbo at a point your mapper didnt expect (or more to the point couldnt do during mapping as it didnt have the nitrous to spool it earlier), then he might not have good guesses in there, but in the case of the MSD chip I was using, it was perfect.