Let's say your wide open Afr is 12:1 at 90 degrees, what would it be at the same place but at 50 degrees? I have a friend who is lean and wondering how much the temp would affect it

Too many variables. Na or blower. What kind of blower of its forced?

N/A 454, 800 holley, 500hp on the dyno. Just curious in general I guess

.5-.75 is what I have seen change, I monitor full time for this reason...

Both myself and Mild thunder were lean in the 50*- 60* weather. I added jet last weekend and increased powervalve restrictions orfices

He is close to 14:1 from 12:1 before so something else is up. Not running it hard because of this. I figured .3 or so for the temp.

10*F is 1% horsepower.

Also, during fall, in the North, we see higher pressure systems in our weather than other times of the boating year.

Again.