Air Temp vs. AFR
 

Im in the process of Tuning my Turbo 1st gen, However now that the temps have dropped significantly I need to start correcting. Is there any baseline that i could follow ie. for every 10 degree drop, 10% more fuel.

Not sure if this really makes a difference but these are the Specs:
S4 13BT
Microtech ECU
FMIC
Stock Turbo at 8 PSI for the moment
MSD Race Wires

I've been tuning for mid-low 14's AFR under Vaccum and dropping to 12's up to 6psi, then 11's for 8 psi. Car Pulls Really nice.

Also on a side note: I've been pulling 2 degrees of Timing for every 2 Psi of Boost. Havent had any issues like this, but i'd love some input.

Thanks

There are a couple of threads around here discussing Air Temp corrections. Westbrook has some values he used and tested in the PFC section of the forum. I believe Wargasm had posted some pure mathematical calculations too.