I realize this isn't a sexy area to talk about
but I am curious what kind of AFR targets make sense (and why) for high vacuum situations. I recall datalogging my stock setup targeting ~20:1.
My thinking (hypothesizing) is that maybe a little fuel (14:1?) would be good to run at high RPM + high vacuum in our cases since this is usually indicative of the end of a WOT run and either:
- a shift up, in which case it might be better left alone
- engine braking (entering a turn) - could use the time to do a little cooling while off load
- braking just before a downshift - could use the time to do a little cooling while off load
Perhaps I'm naive, but it seems like this is an area we're kind of free to play with a bit.
I'm not really able to find any good information on it.