I'd highly recommend moving your boost gauge sensor (for gauge readout in the cab) to before the filter.Thank you for the detailed explanation! Everything is set up as you described and I have been doing everything like you describe in shooting for a 16 psi boost EXCEPT that I have my boost sensor after the filter and not before. My thinking was to protect the sensor by putting after the filter but perhaps that restriction is not giving me a true measurement of manifold boost. THANK YOU for the clarification- I will switch that around.
With my recent SV adjustments, this may be my issue...Fueling is a component of creating boost.Your spill valve may be set at a point that the amount of fuel you are able to receive will only create a maximum of 14PSI of boost.
So, to create more boost will require more fuel. However, more fuel will also create more heat. Your goal is to adjust both in conjunction to to find a sweet spot that produces sufficient boost to help offset the additional heat generated by the additional fuel. Those of us intercooled at running max boost pressures that are actually dictated by the amount of fuel the IP will deliver, not the max boost the turbo is capable of producing. My boost controller for instance is bottomed out. I believe Nick's is as well. But, because of the intercooler, we can utilize the additional fuel without creating a heat problem once the pump is turned up.
It's sort of a balancing act, and every injection pump will produce slightly different results.
With all the diesels I have tuned, no 2 are set up exactly the same. They all take a bit of trial and error. I can for instance get a 300TDI Land Rover engine pretty close by ear and feel, but it still requires test runs to wring out all the power it is capable of producing while not getting the EGT's too high on sustained pulls. And, they vary wildly on where that is. I have not tinkered around on that many LandCruiser engines, but that has been my experience on the ones I have seen and really nearly every other diesel that isn't 100% ECU controlled.
As per the pictures I put up earlier in the thread, you want the bleed valve between the filter and map sensor. The filter is a restriction, which allows the bleed valve to successfully bleed off the boost. Without it, there would be a virtually unlimited supply of air from the intake manifold, making it not work properly.sweet, was just worried if the two T's are 10-15cm apart on the same line the bleed off would would still effect the line pressure and put the gauge off.