12:1 IS to high for some applications, Expecially if you got Aftermarket Injectors. Picture This: You are running 10 PSI of Boost on the turbo, and you have a 12:1 FMU. The vacume line is atached to the Intake Manifold, thats how the FMU knows. You boost to 10 PSI. (12*10=120) so you have 120 PSI of fuel, not including the 40PSI that you have at 0 boost. so that is roughly 160 PSI of fuel!! Not many fuel pumps can handle that, yet alone any fuel systems. So many Turboers use HonData or an AFC to tune the ecu to do it automaticly. Most Turbo Dudes, will say Fuck the FMU. Just because they are included in some Turbo Kits, doesn't mean they are very good.
And NO, Fuel Regulators are not the same as Fuel Managment Units, but kinda, in the fact that they controlle fuel.