Micra Ed said:
At over 1.2-1.3 bar stock MAF is no good at all. Z32 becomes no option. IF the actuator spring is not very strong, then to get more than 1.5 bar may become difficult, if you want to run this I would get a stronger actuator, Typically around a bar.
Just to add to Ed's comments, I'd suspect it is the actuator from how you explain it. If you look at it in it's simplest terms, all the boost control unit is doing, is taking a reading of pressure, and from that reading, telling the solenoid to open or close. As it's working up to 1.5 bar, there is no justification to assume it's broken.
Also, all the MAF does, is measure airflow and turn that reading into a voltage. Again, in simple terms, your just re-calibrating the ecu to accept those new voltages, (as the Z32 clearly differs in these from the stock MAF) so that it can use them in it's calculations for fuelling etc... I'd assume this is just a table change, similar to any remapping process ?!
It would seem that Noble are just trying to fob you off.As above, I'd go somewhere else !
Paul