One Bob
Just read on the DD site that I was wrong in getting this type of adjustment for the VNT
PLEASE NOTE: These can be used for controlling the boost on WASTEGATE TURBOCHARGERS ONLY. These will NOT control the boost on VNT Vaccum Turbochargers.
And as you mentioned it may have only been 4-6 psi and this would not have solved the issue anyway if expected high boost is going to be over 35psi (not that I have any desire to run boost at this level, just does it).
Be interested in how you have plumbed your vac line to get it working, the flutter issues I have at present at best guess is that it is not being enough vac to open the vanes and at 26 psi it literally is acting like an engine exhaust brake which just happens to correspond on a light foot at around 2500 rpm, engines brakes boost drops, revs rise boost rise and engine brakes again etc...
The only turbotech one I saw was similar to the one I got, not a pneumatic style which I am looking at now, by HDI, but it is the plumbing that I got to be sure of and exactly where does enough vacuum be produced to run a VNT?

