Quote Originally Posted by mudski View Post
On my old Di the boost limit was 16psi, yes not via the MAP sensor as you say, just thats when the stupid thing would just a have hissy fit and go into limp mode, at 16psi, or 14psi if I wound in the needle valve for faster spool up. After changing out the MAF housing for a high flow housing, no limp, no hissy fits, nothing, I wound the boost out to 30psi and still nothing. Drove great.
This is a non-sense mate.
reducing the MAF voltage makes the ECM believe there is less air than real. So, the ECM requests less fuel to the pump.
Pushing boost, when reducing the MAF voltage, results in increasing the AFR by reducing the fuel injection.

The only way to get the most of our 3.0 motor is to control the MAF value at all times by using the RPM signal, and manage the turbo vanes directly to maximize the MAF value. I explained all this in details on a Patrol site, and many abandonned dawes+needle for dawes + 2 needles, and now the magic box. That one makes an unbelievable difference.
I am just sharing here the result of the 18 months I spent full time of deep analysis and development to overcome once for all the limits of my own Patrol owned for 21 years now.

The problem with beliefs which have been going on for so long, is that it is hard to believe they were just wrong. I have been misled myself, so I know what it is ! I have been running my home made electronic VNT controller including a LIMP avoidance function, and my old lady became a young girl, climbing like never, to the top of the highest mountains I have around.