The fixed AFR tuning does lean out the fuel above maximum torque more than below resulting in the fuel values being closer to 12.2AFR without WI. This should result in a greater % increase of power at the higher rpms and help flatten out the torque curve. But you do not want to remove so much fuel that the calculated AFR without WI is leaner than 12.2 AFR as you will loose power.
I am now starting to experiment with doing some pre-turbo WI after reading this thread:
http://www.rx7club.com/showthread.php?t=987107
I am comparing normal WI nozzles with a different type of nozzle that only can be used in the filter where the air flow is parallel with the injection flow.
http://www.bete.com/pdfs/BETE_PJ.pdf
For best pre-turbo injection, axial flow is best to prevent water from wetting the sides of the filter or ducts. See pictures of mine in the filter.
I want to thank RiceRacing and Peter94RX7.