Type-R Chasis and Civic SI chasis are within about 10-15 pounds. Driver will wash that out most of the time.

171 isn't too low. I would like to see a list of the actual mods. I am gonna venture a guess it isn't a 2.5" collector header. The Ignition stuff isn't doing much for you. WHo tuned the VAFC and what did they tune it to? There might be more power there with a different tuner.

I ran a 13.8 @ 101 with my R with i/h and untuned power FC making about 179 hp. On street tires.