N/A performance tune

[yaris2010RS]

Hey all, so as most of you know i have recently switched from boosted to Stock. i cant wait to get boosted again but in the mean time i do plan to do some "wallet friendly" mods to this engine (its painfully slow). its 99% stock. Stock intake (carbon trap removed) stock header, stock midpipe, aftermarket axel back, 5w-20 oil and 87 octane fuel (im not gonna miss 91 and untra 94), i did reinstall my AEM Wideband AFR sensor into my stock midpipe to see what the stock ECM is doing.

I do plan to do this correct by doing a dyno run prior to anything and as long as i find a reasonable rate for 3 pulls i plan to dyno after each small mod.

Basically NA tuning is new to me (We actually tuning in general is, hence the fact im back to stock), i know our EMC has a fuel econo tune on it, and i love % changes. before we get into the nit-grits of my method of madness what kind of tune would benifit a NA engine. I have considered ways to set off the ECM to change output % but would % more fuel benefit to more Power?

Stock ECM tune AFR (for all you wondering) is 14.6-15.6 for all conditions untill open loop conditions are met. where it drops down to a very steady 12.4.

basically to make more power on a NA engine on a very small budget would i be looking to gain a bit more fuel or would this be useless and i should focus my efforts on timing?