Turbo upgrade from stock

[VFRegal]

Hi everyone, hopefully this isn't too much of a basic question for these forums.
I have an adm S15 with the stock turbo.
Normal mods with increased boost and my road tune to suit.
The tune is ok for my current setup but I am about to install a td05-18g turbo.
My concern is where abouts to start with timing.
Is it best to reset back to the original stock timing map, or should I take some timing out of the original map before I get the afr's sorted ?

Would anyone be kind enough to share a tune or map for a similar setup for me to take a gander at ?

Thanks !