the turbos also used the MAF, its on the intake side so theres no pressure. They're not very reliable. It wasnt until I think saab came out with the trionic system that a single computer controlled boost, fuel, and timing all together. Prior to that you had a few independent brains. ECU setting fuel, timing sometimes with an EZK brain, etc.
Yup. T5 used a combination of MAP and temp sensors to do its fuel mappings. The system was able account for fuel quality by adjusting the spark timing and boost amount via controlling a solenoid valve down to whatever the actually physical waste gate spring was set to.
The later T7 system involved a MAF sensor behind the intake, while still retaining the temp sensors and MAP but changed the fuel mapping in the system to be a speed - density system for greater control and better boost handling with large temp and altitude changes. (T5 shot for a pressure value t7 shot for a target air mass).
There is software called t5suite / t7suite that allowed you to remap everything in the ECU, basically letting you modify the system in every possible way but not making you do all the setup that a complete stand alone unit would make you setup. It was and is, amazing. You could flash an ECU via BDM interface out of car, and in later T7 models actually make real time changes on a laptop that would immediately take effect. Later you could write them to the ECU flash (it requires more than 12v to flash, although some people rigged things up so they could also flash the memory in car).
Good times. I still have a t7 Saab on my lawn. My custom tune isn't the best, but it went damn good.
Interesting to note, the MAF in the t7 could be placed on the pressure side of the world and it would work perfectly fine minus the fact that they would die a lot quicker due to oils and such on the pressure side of the turbo. People sometimes did this as it was the only way to run a true blow off valve for cool effect. If the MAF is in the stick location and you do not recirculate that air, the car would be fueling for XYZ air density but you'd have dumped some out of the closed system and it ran rich as hell and like crap .
