Matthew Jenks

if u mess with the pcm do you have to dyno the rx8

Loki

iTrader: (1)

You shouldn't mess with the PCM. There is nothing to be had there.
A dyno helps you tune, it's not a requirement after you have tuned.

BoostedRX

Don't mess with the PCM unless you know what you are doing. If you are referring to changing fuel table, ignition time, ext...
provided you know how to properly tune a rotary(and not kill it) then that should be done on a proper dyno for the best results.