Adjusting a ZD30 VNT

[the evil twin]

Half a turn made a noticeable difference. I only got to 80kph but I could not get it to over boost like before. Under 2000rpm pickup was a little better and the egt were higher. The boost was 2 to 3 psi lower. When it would normally hit 22psi and drop off it now only hits 17psi and keeps going. I will try it on the hwy over the weekend and report back.

Yeah, pretty much what I had... I will amend my post before someone has a cow as the 38 PSI I quoted was absolute not gauge which equates to about 23 PSIG

[Fity]

I have done a couple hundred Ks over the weekend. On the highway it still trips out on over boost, but does not go over 17psi. The egt is about 50deg higher probably as a result of lower boost when accelerating being compensated for with more fuel.

I will leave it where it its until I fit the dawes then have another play.

[Forest1970]

Yeah, pretty much what I had... I will amend my post before someone has a cow as the 38 PSI I quoted was absolute not gauge which equates to about 23 PSIG

What do you mean by 38PSI absolute and how/where did you measure this?
Just curious and interested , thanks

[nissannewby]

Absolute is when you add boost and atmospheric pressure. Atmospheric is around 14.5 psi. Most gauges are calibrated to give you a boost reading on top of that.

[threedogs]

Fity what are your EGTs and boost PSI at 100 kph ???? 250-300 degree C and 10 PSI ?????
Sort of rule of thumb is to have 10 psi at 2000 RPM

[Forest1970]

Absolute is when you add boost and atmospheric pressure. Atmospheric is around 14.5 psi. Most gauges are calibrated to give you a boost reading on top of that.

So Zero on a Gauge is actually 14.5 PSI being atmospheric pressure?