We know, thanks to Ian C's observations, that the Jap ECU goes all-out on the injectors when it sees more than 1 bar of manifold pressure.
What happens if you had a single turbo, so you had a large mass of air but the pressure was still within the stock system's range (0 - 0.99 bar)?
Has anybody measured the reactions of the stock fuel system to differing levels of air mass? If I went single-turbo, I could just use an A/F meter and see if everything's OK, but it would be pretty dangerous raising boost until things started to go lean. I envisage that with a 58/60 sized turbo, I wouldn't be exceeding 0.9bar or something, so would be within the stock fuel system's sensor-reading range, but the air density would be much higher than with stock turbos.
I'm a little mystified because I've just read about how MAP systems work, and it seems like all MAP does is provide a way of coming out with a MAF measurement. So why not just use a MAF sensor in the first place?
From what I read, MAP systems measure manifold air pressure and density (which is inversely proportional to the air's temperature) and refer this against an engine speed map which tables how much air the engine gobbles up for a given rpm, the end result being a calculation of mass air flow, according to Wikipedia.
So why would people want to change from MAF to MAP, i.e. with a MAP2 ECU ?