Sam Lin

14.7:1 is stoichiometric, depending on whether air/fuel ratio or fuel/air ratio is being read, higher or lower will be rich or lean. 14.7 is center. Usually, air/fuel ratio is read, making a 12 rich while a 16 is lean.

Sam

JustinL

I'll just add that leaner generates more heat so you will get a faster turbo spool up, but at high boost this can lead to detonation. What I was shooting for was 14:1 off boost and then 12:1 on boost. I guess 12:1 is pretty safe yet still being reasonably efficient.