13.4 is a 'can do' with some important mods, you won't get the stockie going like that un-fortunately cause of the exhaust if nothing else.
My 205's , even tho simex, are way under sized for road rubber let alone the drags.
Didn't do a thing with the s-afc II except watch the pretty blue screen for 'knocking'. I only installed it the night before and since the instructions are all in jap i was not prepared to touch the A/F settings, I'll leave it for the dyno some time in the next month.
Note: * that I did a bunch of 13.5's and a 13.6 that night, it's no fluke.
* Simex (read cheap'o) 205's, no octane booster , stock ecu , stock intercooler, 10psi.